TBD Meeting (5328-21)

Maribavir, an investigational antiviral agent with a novel mechanism of action, was superior to other antiviral strategies at clearing cytomegalovirus (CMV) viremia and controlling symptoms in hematopoietic cell or solid-organ transplant recipients, results of a phase 3 clinical trial showed.

CDC

CMV viremia clearance at study week 8 was seen in 55.7% of all patients randomized to receive maribavir, compared with 23.9% for patients assigned to receive investigator-assigned therapy (IAT), Francisco Marty, MD, from the Dana-Farber Cancer Institute in Boston reported at the Transplant & Cellular Therapies Meetings.

“Maribavir’s benefit was driven by lower incidence of treatment-limiting toxicities, compared with IAT,” he said a late-breaking abstract session during the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

“Available anti-CMV antivirals are limited by development of resistance and toxicities, particularly myelosuppression with the use of valganciclovir and nephrotoxicity with the use of foscarnet and cidofovir. Alternative treatment options are required to address this unmet medical need,” he said.

Maribavir inhibits the CMV UL97 protein kinase and is thought to affect several critical processes in CMV replication, including viral DNA synthesis, viral gene expression, encapsidation, and egress of mature capsids from the nucleus.
 

Details of trial

In the phase 3 SHP620-30e trial (NCT02931539), Dr. Marty and colleagues enrolled patients with relapsed or refractory CMV infections after hematopoietic cell transplant (HCT) or solid-organ transplant (SOT) and after stratification by transplant type and screening CMV DNA level randomly assigned them on a 2:1 basis to receive either maribavir 400 mg twice daily (235 patients) or IAT (117 patients), consisting of either ganciclovir/valganciclovir, foscarnet, cidofovir, or combined foscarnet and val/ganciclovir.

The primary endpoint of viremia clearance at 8 weeks was defined as plasma CMV DNA less than 137 IU/mL in two consecutive tests at a central laboratory at least 5 days apart beginning at the end of week 8.

The trial met its primary endpoint, with a viremia clearance rate of 55.7% with maribavir versus 23.9% with IAT.

The viremia clearance rates were similar in each of the transplant groups: 55.9% versus 20.8%, respectively, in patients who underwent HCT, and 55.6% versus 26.1% in patients who underwent SOT (P < .001).

Clearance rates among patients with CMV DNA below 9,100 IU/mL at baseline were 62.1% with maribavir versus 24.7% with IAT. Among patients with baseline CMV DNA of 9100 IU/mL or above, the respective rates were 43.9% versus 21.9%.

CMV viremia clearance continued from week 8 to week 16 in 18.7% of patients assigned to maribavir and to 10.3% of patients randomized to IAT (P < .013).

The median time to first CMV viremia clearance as 22 days with maribavir versus 27 days with IAT (P = .039).

All-cause mortality was similar between the groups, at 11.5% versus 11.1%, respectively.

The incidences of serious and severe treatment-emergent adverse events (TEAE) were 38.5% and 32.1%, respectively, in the maribavir group, and 37.1% and 37.9% in the IAT group.

Any TEAE leading to study drug discontinuation was less common with maribavir, occurring in 13.2% of patients, compared with 31.9% of patients on IAT. Serious TEAEs leading to drug discontinuation occurred in 8.5% versus 14.7%, respectively.

Serious TEAEs leading to death occurred in 6.8% of patients on maribavir versus 5.2% of those on IAT.
 

Role of letermovir

In the question-and-answer session following the presentation, comoderator Monalisa Ghosh, MD, from the University of Michigan, Ann Arbor, asked whether any patients in the study were currently on letermovir (Prevymis) prophylaxis, and whether any patients had previously been treated with letermovir but had CMV reactivation and were then treated on study.

Dr. Marty noted that the trial was designed before letermovir was approved for CMV prophylaxis in adults who have undergone an allogeneic HCT.

“Nobody was on letermovir at the beginning of the trial,” he replied, but noted that some patients who were enrolled and had infections that were refractory or resistant to valganciclovir, foscarnet, or a combination of the two received letermovir as secondary prophylaxis.

“I haven’t got the data to tell you how often [letermovir] was used; I think part of the lack of mortality benefit [with maribavir] may be due to the fact that people jumped into secondary prophylaxis with letermovir to minimize the toxicities that we saw,” he said.

Although maribavir has not as of this writing received Food and Drug Administration approval, the drug may be available to some patients through a compassionate-use program from Takeda, Dr. Marty noted.

The study was funded by Shire ViroPharma. Dr. Marty disclosed research funding from Shire and from others. Dr. Ghosh had no relevant disclosures.

Maribavir, an investigational antiviral agent with a novel mechanism of action, was superior to other antiviral strategies at clearing cytomegalovirus (CMV) viremia and controlling symptoms in hematopoietic cell or solid-organ transplant recipients, results of a phase 3 clinical trial showed.

CDC

CMV viremia clearance at study week 8 was seen in 55.7% of all patients randomized to receive maribavir, compared with 23.9% for patients assigned to receive investigator-assigned therapy (IAT), Francisco Marty, MD, from the Dana-Farber Cancer Institute in Boston reported at the Transplant & Cellular Therapies Meetings.

“Maribavir’s benefit was driven by lower incidence of treatment-limiting toxicities, compared with IAT,” he said a late-breaking abstract session during the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

“Available anti-CMV antivirals are limited by development of resistance and toxicities, particularly myelosuppression with the use of valganciclovir and nephrotoxicity with the use of foscarnet and cidofovir. Alternative treatment options are required to address this unmet medical need,” he said.

Maribavir inhibits the CMV UL97 protein kinase and is thought to affect several critical processes in CMV replication, including viral DNA synthesis, viral gene expression, encapsidation, and egress of mature capsids from the nucleus.
 

Details of trial

In the phase 3 SHP620-30e trial (NCT02931539), Dr. Marty and colleagues enrolled patients with relapsed or refractory CMV infections after hematopoietic cell transplant (HCT) or solid-organ transplant (SOT) and after stratification by transplant type and screening CMV DNA level randomly assigned them on a 2:1 basis to receive either maribavir 400 mg twice daily (235 patients) or IAT (117 patients), consisting of either ganciclovir/valganciclovir, foscarnet, cidofovir, or combined foscarnet and val/ganciclovir.

The primary endpoint of viremia clearance at 8 weeks was defined as plasma CMV DNA less than 137 IU/mL in two consecutive tests at a central laboratory at least 5 days apart beginning at the end of week 8.

The trial met its primary endpoint, with a viremia clearance rate of 55.7% with maribavir versus 23.9% with IAT.

The viremia clearance rates were similar in each of the transplant groups: 55.9% versus 20.8%, respectively, in patients who underwent HCT, and 55.6% versus 26.1% in patients who underwent SOT (P < .001).

Clearance rates among patients with CMV DNA below 9,100 IU/mL at baseline were 62.1% with maribavir versus 24.7% with IAT. Among patients with baseline CMV DNA of 9100 IU/mL or above, the respective rates were 43.9% versus 21.9%.

CMV viremia clearance continued from week 8 to week 16 in 18.7% of patients assigned to maribavir and to 10.3% of patients randomized to IAT (P < .013).

The median time to first CMV viremia clearance as 22 days with maribavir versus 27 days with IAT (P = .039).

All-cause mortality was similar between the groups, at 11.5% versus 11.1%, respectively.

The incidences of serious and severe treatment-emergent adverse events (TEAE) were 38.5% and 32.1%, respectively, in the maribavir group, and 37.1% and 37.9% in the IAT group.

Any TEAE leading to study drug discontinuation was less common with maribavir, occurring in 13.2% of patients, compared with 31.9% of patients on IAT. Serious TEAEs leading to drug discontinuation occurred in 8.5% versus 14.7%, respectively.

Serious TEAEs leading to death occurred in 6.8% of patients on maribavir versus 5.2% of those on IAT.
 

Role of letermovir

In the question-and-answer session following the presentation, comoderator Monalisa Ghosh, MD, from the University of Michigan, Ann Arbor, asked whether any patients in the study were currently on letermovir (Prevymis) prophylaxis, and whether any patients had previously been treated with letermovir but had CMV reactivation and were then treated on study.

Dr. Marty noted that the trial was designed before letermovir was approved for CMV prophylaxis in adults who have undergone an allogeneic HCT.

“Nobody was on letermovir at the beginning of the trial,” he replied, but noted that some patients who were enrolled and had infections that were refractory or resistant to valganciclovir, foscarnet, or a combination of the two received letermovir as secondary prophylaxis.

“I haven’t got the data to tell you how often [letermovir] was used; I think part of the lack of mortality benefit [with maribavir] may be due to the fact that people jumped into secondary prophylaxis with letermovir to minimize the toxicities that we saw,” he said.

Although maribavir has not as of this writing received Food and Drug Administration approval, the drug may be available to some patients through a compassionate-use program from Takeda, Dr. Marty noted.

The study was funded by Shire ViroPharma. Dr. Marty disclosed research funding from Shire and from others. Dr. Ghosh had no relevant disclosures.

Maribavir, an investigational antiviral agent with a novel mechanism of action, was superior to other antiviral strategies at clearing cytomegalovirus (CMV) viremia and controlling symptoms in hematopoietic cell or solid-organ transplant recipients, results of a phase 3 clinical trial showed.

CDC

CMV viremia clearance at study week 8 was seen in 55.7% of all patients randomized to receive maribavir, compared with 23.9% for patients assigned to receive investigator-assigned therapy (IAT), Francisco Marty, MD, from the Dana-Farber Cancer Institute in Boston reported at the Transplant & Cellular Therapies Meetings.

“Maribavir’s benefit was driven by lower incidence of treatment-limiting toxicities, compared with IAT,” he said a late-breaking abstract session during the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

“Available anti-CMV antivirals are limited by development of resistance and toxicities, particularly myelosuppression with the use of valganciclovir and nephrotoxicity with the use of foscarnet and cidofovir. Alternative treatment options are required to address this unmet medical need,” he said.

Maribavir inhibits the CMV UL97 protein kinase and is thought to affect several critical processes in CMV replication, including viral DNA synthesis, viral gene expression, encapsidation, and egress of mature capsids from the nucleus.
 

Details of trial

In the phase 3 SHP620-30e trial (NCT02931539), Dr. Marty and colleagues enrolled patients with relapsed or refractory CMV infections after hematopoietic cell transplant (HCT) or solid-organ transplant (SOT) and after stratification by transplant type and screening CMV DNA level randomly assigned them on a 2:1 basis to receive either maribavir 400 mg twice daily (235 patients) or IAT (117 patients), consisting of either ganciclovir/valganciclovir, foscarnet, cidofovir, or combined foscarnet and val/ganciclovir.

The primary endpoint of viremia clearance at 8 weeks was defined as plasma CMV DNA less than 137 IU/mL in two consecutive tests at a central laboratory at least 5 days apart beginning at the end of week 8.

The trial met its primary endpoint, with a viremia clearance rate of 55.7% with maribavir versus 23.9% with IAT.

The viremia clearance rates were similar in each of the transplant groups: 55.9% versus 20.8%, respectively, in patients who underwent HCT, and 55.6% versus 26.1% in patients who underwent SOT (P < .001).

Clearance rates among patients with CMV DNA below 9,100 IU/mL at baseline were 62.1% with maribavir versus 24.7% with IAT. Among patients with baseline CMV DNA of 9100 IU/mL or above, the respective rates were 43.9% versus 21.9%.

CMV viremia clearance continued from week 8 to week 16 in 18.7% of patients assigned to maribavir and to 10.3% of patients randomized to IAT (P < .013).

The median time to first CMV viremia clearance as 22 days with maribavir versus 27 days with IAT (P = .039).

All-cause mortality was similar between the groups, at 11.5% versus 11.1%, respectively.

The incidences of serious and severe treatment-emergent adverse events (TEAE) were 38.5% and 32.1%, respectively, in the maribavir group, and 37.1% and 37.9% in the IAT group.

Any TEAE leading to study drug discontinuation was less common with maribavir, occurring in 13.2% of patients, compared with 31.9% of patients on IAT. Serious TEAEs leading to drug discontinuation occurred in 8.5% versus 14.7%, respectively.

Serious TEAEs leading to death occurred in 6.8% of patients on maribavir versus 5.2% of those on IAT.
 

Role of letermovir

In the question-and-answer session following the presentation, comoderator Monalisa Ghosh, MD, from the University of Michigan, Ann Arbor, asked whether any patients in the study were currently on letermovir (Prevymis) prophylaxis, and whether any patients had previously been treated with letermovir but had CMV reactivation and were then treated on study.

Dr. Marty noted that the trial was designed before letermovir was approved for CMV prophylaxis in adults who have undergone an allogeneic HCT.

“Nobody was on letermovir at the beginning of the trial,” he replied, but noted that some patients who were enrolled and had infections that were refractory or resistant to valganciclovir, foscarnet, or a combination of the two received letermovir as secondary prophylaxis.

“I haven’t got the data to tell you how often [letermovir] was used; I think part of the lack of mortality benefit [with maribavir] may be due to the fact that people jumped into secondary prophylaxis with letermovir to minimize the toxicities that we saw,” he said.

Although maribavir has not as of this writing received Food and Drug Administration approval, the drug may be available to some patients through a compassionate-use program from Takeda, Dr. Marty noted.

The study was funded by Shire ViroPharma. Dr. Marty disclosed research funding from Shire and from others. Dr. Ghosh had no relevant disclosures.

Although the only pediatric indication for chimeric antigen receptor T-cell therapy currently approved by the Food and Drug Administration is B-lineage acute lymphoblastic leukemia (ALL) that is refractory to at least two frontline induction attempts or is in second or later relapse, clinical trials of CAR-T therapy for pediatric solid tumors are also currently in progress, said Gregory Yanik, MD, from the CS Mott Children’s Hospital at the University of Michigan, Ann Arbor, at the Transplant & Cellular Therapies Meetings.

In his presentation, Dr. Yanik discussed progress in solid tumor studies as well as some issues involving the current use of CAR-T therapy for ALL.

Solid tumor studies

Malignancies such as sarcomas, brain tumors, and neuroblastomas pose unique challenges, “In contrast to hematologic malignancies, the protein we’re targeting may not be present on the cell surface of all the tumor cells. There are lower-expression profiles, and this is a problem. In fact, many people have postulated that with CAR-T for pediatric solid tumors we’ll have to do repeated cycles, almost like we do with chemotherapy,” he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

There are currently 14 studies of CAR-T for central nervous system tumors in children, targeting either epidermal growth factor receptor (EGFR) in glioblastoma multiforme and high-grade gliomas, HER2 in a variety of CNS tumors, the GD2 antigen on pontine gliomas, and the checkpoint molecular B7H3 in medulloblastomas and pontine gliomas.

“In sarcomas in kids there are currently 12 trials in progress. Most of the targeting epitopes are targeting either HER2 or GD2. Repetitive CAR-T infusions are being used in several of these trials in sarcomas.

For neuroblastomas there are currently 13 studies in progress, nearly all of which target GD2. Some of the trials include combining CAR-T with immune checkpoint inhibitors or C7R, an engineered cytokine driver designed to prevent T-cell exhaustion.

In addition, several trials of tumor pulsed dendritic cell vaccines are underway for treatment of children with Wilms tumor, Dr. Yanik noted.
 

Unresolved procedural questions

It’s still early days in CAR-T therapy, and there are several still unanswered questions regarding optimal therapy for and management of patients undergoing CAR-T procedures, Dr. Yanik said.

For example, the optimal time to collect T cells during apheresis is still unclear, he said. Collecting prior to reinduction therapy raises the risk of transducing leukemic cells, while collecting after reinduction may result in inadequate quantity or quality of cells. Regardless of when cells are collected, apheresis should be performed only when the absolute lymphocyte count is above 500/mcL or the CD3 count is above 150/mcL at the time of apheresis.

In the case tisagenlecleucel (Kymriah), his center typically collects 1x10⁹ CD3 cells regardless of age or weight.

The number of CAR T-cells infused also appears to matter, as responses are improved at CAR-T doses above 1.5x10⁶/kg, while risk for higher-grade cytokine release syndrome (CRS) occurs at higher infusion doses.
 

Blinatumomab or inotuzumab?

Along with CAR-T, two other agents, the bispecific T-cell engager blinatumomab (Blincyto) and the antibody conjugate inotuzumab ozogamicin (Besponsa) are also approved for the treatment of patients with relapsed/refractory B-cell ALL.

Like CAR-T therapy, the primary toxicities associated with blinatumomab are CRS and neurologic adverse events, whereas at inotuzumab is largely associated with hematologic and hepatic toxicities.

The logistics of therapy differ widely, with a 28-day infusion required for blinatumomab, compared with weekly dosing of inotuzumab, and the multiple visits for apheresis and infusion required for CAR-T.

Blinatumomab is approved for both children and adults with relapsed/refractory ALL, but inotuzumab is approved only for adults, and CAR-T with tisagenlecleucel is approved only for children in this indication.
 

CD-19 expression

There is evidence to suggest that CD19 expression prior to CAR-T has an effect on outcomes, Dr. Yanik said.

“Does blinatumomab pre–CAR-T impact outcome? The answer is probably yes,” he said.

He referred to a study by investigators at the Children’s Hospital of Philadelphia showing that, “if you’re giving blinatumomab prior to CAR-T therapy, you’re potentially reducing the cell-surface expression of CD19 on your leukemic blasts, and now while you’re bringing these patients in for CAR-T therapy, you’re getting a much higher population of dim CD19 expressers, and this is associated with a higher relapse rate and lower remission rate.”
 

Predicting relapse

Dr. Yanik referred to a study, currently unpublished, which will show that next-generation sequencing (NGS) is more sensitive than flow cytometry for detection of minimal residual disease (MRD), and that MRD analysis of marrow was more sensitive than analysis of peripheral blood.

“Poor outcomes were seen post CAR-T for patients who were in morphologic remission on day 28 or day 100, but had positive MRD. This especially held true if it was next-gen sequencing MRD-positive at day 100, for which relapse rates were over 95%,” he said.

The absence of B-cells is a surrogate marker for the persistence of CAR-T, and conversely, the recovery of CD19-positive B cells may be a predictor for relapse, especially if the B-cell recovery occurs within the first 6 months following CAR-T infusion.
 

Transplant after CAR-T?

Bone marrow transplant after CAR-T is recommend for patients with high risk of relapse, including those with B-cell recovery within the first 6 months after CAR-T, patients with MRD positivity at days 28 or 100, and patients with mixed lineage leukemia.

“Should we transplant good-risk patients, meaning, if you have NGS-MRD negative patients, is there a role for transplant? You have to look at the risk versus benefit there. These patients may have a cure rate that’s in the 80%-plus range, could we potentially optimize that even more if we consolidate them with an allo[geneic] transplant,” Dr. Yank said.
 

Move CAR-T up front?

A Children’s Oncology Group study is currently examining whether giving CAR-T therapy to patients with MRD of 0.01% or greater following first consolidation could result in lower tumor burden, fewer relapse, and less CRS with CAR-T.

Dr. Yanik reported that he had no conflicts of interest to disclose.

Although the only pediatric indication for chimeric antigen receptor T-cell therapy currently approved by the Food and Drug Administration is B-lineage acute lymphoblastic leukemia (ALL) that is refractory to at least two frontline induction attempts or is in second or later relapse, clinical trials of CAR-T therapy for pediatric solid tumors are also currently in progress, said Gregory Yanik, MD, from the CS Mott Children’s Hospital at the University of Michigan, Ann Arbor, at the Transplant & Cellular Therapies Meetings.

In his presentation, Dr. Yanik discussed progress in solid tumor studies as well as some issues involving the current use of CAR-T therapy for ALL.

Solid tumor studies

Malignancies such as sarcomas, brain tumors, and neuroblastomas pose unique challenges, “In contrast to hematologic malignancies, the protein we’re targeting may not be present on the cell surface of all the tumor cells. There are lower-expression profiles, and this is a problem. In fact, many people have postulated that with CAR-T for pediatric solid tumors we’ll have to do repeated cycles, almost like we do with chemotherapy,” he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

There are currently 14 studies of CAR-T for central nervous system tumors in children, targeting either epidermal growth factor receptor (EGFR) in glioblastoma multiforme and high-grade gliomas, HER2 in a variety of CNS tumors, the GD2 antigen on pontine gliomas, and the checkpoint molecular B7H3 in medulloblastomas and pontine gliomas.

“In sarcomas in kids there are currently 12 trials in progress. Most of the targeting epitopes are targeting either HER2 or GD2. Repetitive CAR-T infusions are being used in several of these trials in sarcomas.

For neuroblastomas there are currently 13 studies in progress, nearly all of which target GD2. Some of the trials include combining CAR-T with immune checkpoint inhibitors or C7R, an engineered cytokine driver designed to prevent T-cell exhaustion.

In addition, several trials of tumor pulsed dendritic cell vaccines are underway for treatment of children with Wilms tumor, Dr. Yanik noted.
 

Unresolved procedural questions

It’s still early days in CAR-T therapy, and there are several still unanswered questions regarding optimal therapy for and management of patients undergoing CAR-T procedures, Dr. Yanik said.

For example, the optimal time to collect T cells during apheresis is still unclear, he said. Collecting prior to reinduction therapy raises the risk of transducing leukemic cells, while collecting after reinduction may result in inadequate quantity or quality of cells. Regardless of when cells are collected, apheresis should be performed only when the absolute lymphocyte count is above 500/mcL or the CD3 count is above 150/mcL at the time of apheresis.

In the case tisagenlecleucel (Kymriah), his center typically collects 1x10⁹ CD3 cells regardless of age or weight.

The number of CAR T-cells infused also appears to matter, as responses are improved at CAR-T doses above 1.5x10⁶/kg, while risk for higher-grade cytokine release syndrome (CRS) occurs at higher infusion doses.
 

Blinatumomab or inotuzumab?

Along with CAR-T, two other agents, the bispecific T-cell engager blinatumomab (Blincyto) and the antibody conjugate inotuzumab ozogamicin (Besponsa) are also approved for the treatment of patients with relapsed/refractory B-cell ALL.

Like CAR-T therapy, the primary toxicities associated with blinatumomab are CRS and neurologic adverse events, whereas at inotuzumab is largely associated with hematologic and hepatic toxicities.

The logistics of therapy differ widely, with a 28-day infusion required for blinatumomab, compared with weekly dosing of inotuzumab, and the multiple visits for apheresis and infusion required for CAR-T.

Blinatumomab is approved for both children and adults with relapsed/refractory ALL, but inotuzumab is approved only for adults, and CAR-T with tisagenlecleucel is approved only for children in this indication.
 

CD-19 expression

There is evidence to suggest that CD19 expression prior to CAR-T has an effect on outcomes, Dr. Yanik said.

“Does blinatumomab pre–CAR-T impact outcome? The answer is probably yes,” he said.

He referred to a study by investigators at the Children’s Hospital of Philadelphia showing that, “if you’re giving blinatumomab prior to CAR-T therapy, you’re potentially reducing the cell-surface expression of CD19 on your leukemic blasts, and now while you’re bringing these patients in for CAR-T therapy, you’re getting a much higher population of dim CD19 expressers, and this is associated with a higher relapse rate and lower remission rate.”
 

Predicting relapse

Dr. Yanik referred to a study, currently unpublished, which will show that next-generation sequencing (NGS) is more sensitive than flow cytometry for detection of minimal residual disease (MRD), and that MRD analysis of marrow was more sensitive than analysis of peripheral blood.

“Poor outcomes were seen post CAR-T for patients who were in morphologic remission on day 28 or day 100, but had positive MRD. This especially held true if it was next-gen sequencing MRD-positive at day 100, for which relapse rates were over 95%,” he said.

The absence of B-cells is a surrogate marker for the persistence of CAR-T, and conversely, the recovery of CD19-positive B cells may be a predictor for relapse, especially if the B-cell recovery occurs within the first 6 months following CAR-T infusion.
 

Transplant after CAR-T?

Bone marrow transplant after CAR-T is recommend for patients with high risk of relapse, including those with B-cell recovery within the first 6 months after CAR-T, patients with MRD positivity at days 28 or 100, and patients with mixed lineage leukemia.

“Should we transplant good-risk patients, meaning, if you have NGS-MRD negative patients, is there a role for transplant? You have to look at the risk versus benefit there. These patients may have a cure rate that’s in the 80%-plus range, could we potentially optimize that even more if we consolidate them with an allo[geneic] transplant,” Dr. Yank said.
 

Move CAR-T up front?

A Children’s Oncology Group study is currently examining whether giving CAR-T therapy to patients with MRD of 0.01% or greater following first consolidation could result in lower tumor burden, fewer relapse, and less CRS with CAR-T.

Dr. Yanik reported that he had no conflicts of interest to disclose.

Although the only pediatric indication for chimeric antigen receptor T-cell therapy currently approved by the Food and Drug Administration is B-lineage acute lymphoblastic leukemia (ALL) that is refractory to at least two frontline induction attempts or is in second or later relapse, clinical trials of CAR-T therapy for pediatric solid tumors are also currently in progress, said Gregory Yanik, MD, from the CS Mott Children’s Hospital at the University of Michigan, Ann Arbor, at the Transplant & Cellular Therapies Meetings.

In his presentation, Dr. Yanik discussed progress in solid tumor studies as well as some issues involving the current use of CAR-T therapy for ALL.

Solid tumor studies

Malignancies such as sarcomas, brain tumors, and neuroblastomas pose unique challenges, “In contrast to hematologic malignancies, the protein we’re targeting may not be present on the cell surface of all the tumor cells. There are lower-expression profiles, and this is a problem. In fact, many people have postulated that with CAR-T for pediatric solid tumors we’ll have to do repeated cycles, almost like we do with chemotherapy,” he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

There are currently 14 studies of CAR-T for central nervous system tumors in children, targeting either epidermal growth factor receptor (EGFR) in glioblastoma multiforme and high-grade gliomas, HER2 in a variety of CNS tumors, the GD2 antigen on pontine gliomas, and the checkpoint molecular B7H3 in medulloblastomas and pontine gliomas.

“In sarcomas in kids there are currently 12 trials in progress. Most of the targeting epitopes are targeting either HER2 or GD2. Repetitive CAR-T infusions are being used in several of these trials in sarcomas.

For neuroblastomas there are currently 13 studies in progress, nearly all of which target GD2. Some of the trials include combining CAR-T with immune checkpoint inhibitors or C7R, an engineered cytokine driver designed to prevent T-cell exhaustion.

In addition, several trials of tumor pulsed dendritic cell vaccines are underway for treatment of children with Wilms tumor, Dr. Yanik noted.
 

Unresolved procedural questions

It’s still early days in CAR-T therapy, and there are several still unanswered questions regarding optimal therapy for and management of patients undergoing CAR-T procedures, Dr. Yanik said.

For example, the optimal time to collect T cells during apheresis is still unclear, he said. Collecting prior to reinduction therapy raises the risk of transducing leukemic cells, while collecting after reinduction may result in inadequate quantity or quality of cells. Regardless of when cells are collected, apheresis should be performed only when the absolute lymphocyte count is above 500/mcL or the CD3 count is above 150/mcL at the time of apheresis.

In the case tisagenlecleucel (Kymriah), his center typically collects 1x10⁹ CD3 cells regardless of age or weight.

The number of CAR T-cells infused also appears to matter, as responses are improved at CAR-T doses above 1.5x10⁶/kg, while risk for higher-grade cytokine release syndrome (CRS) occurs at higher infusion doses.
 

Blinatumomab or inotuzumab?

Along with CAR-T, two other agents, the bispecific T-cell engager blinatumomab (Blincyto) and the antibody conjugate inotuzumab ozogamicin (Besponsa) are also approved for the treatment of patients with relapsed/refractory B-cell ALL.

Like CAR-T therapy, the primary toxicities associated with blinatumomab are CRS and neurologic adverse events, whereas at inotuzumab is largely associated with hematologic and hepatic toxicities.

The logistics of therapy differ widely, with a 28-day infusion required for blinatumomab, compared with weekly dosing of inotuzumab, and the multiple visits for apheresis and infusion required for CAR-T.

Blinatumomab is approved for both children and adults with relapsed/refractory ALL, but inotuzumab is approved only for adults, and CAR-T with tisagenlecleucel is approved only for children in this indication.
 

CD-19 expression

There is evidence to suggest that CD19 expression prior to CAR-T has an effect on outcomes, Dr. Yanik said.

“Does blinatumomab pre–CAR-T impact outcome? The answer is probably yes,” he said.

He referred to a study by investigators at the Children’s Hospital of Philadelphia showing that, “if you’re giving blinatumomab prior to CAR-T therapy, you’re potentially reducing the cell-surface expression of CD19 on your leukemic blasts, and now while you’re bringing these patients in for CAR-T therapy, you’re getting a much higher population of dim CD19 expressers, and this is associated with a higher relapse rate and lower remission rate.”
 

Predicting relapse

Dr. Yanik referred to a study, currently unpublished, which will show that next-generation sequencing (NGS) is more sensitive than flow cytometry for detection of minimal residual disease (MRD), and that MRD analysis of marrow was more sensitive than analysis of peripheral blood.

“Poor outcomes were seen post CAR-T for patients who were in morphologic remission on day 28 or day 100, but had positive MRD. This especially held true if it was next-gen sequencing MRD-positive at day 100, for which relapse rates were over 95%,” he said.

The absence of B-cells is a surrogate marker for the persistence of CAR-T, and conversely, the recovery of CD19-positive B cells may be a predictor for relapse, especially if the B-cell recovery occurs within the first 6 months following CAR-T infusion.
 

Transplant after CAR-T?

Bone marrow transplant after CAR-T is recommend for patients with high risk of relapse, including those with B-cell recovery within the first 6 months after CAR-T, patients with MRD positivity at days 28 or 100, and patients with mixed lineage leukemia.

“Should we transplant good-risk patients, meaning, if you have NGS-MRD negative patients, is there a role for transplant? You have to look at the risk versus benefit there. These patients may have a cure rate that’s in the 80%-plus range, could we potentially optimize that even more if we consolidate them with an allo[geneic] transplant,” Dr. Yank said.
 

Move CAR-T up front?

A Children’s Oncology Group study is currently examining whether giving CAR-T therapy to patients with MRD of 0.01% or greater following first consolidation could result in lower tumor burden, fewer relapse, and less CRS with CAR-T.

Dr. Yanik reported that he had no conflicts of interest to disclose.

A novel T-cell engineered product, Orca-T (Orca Bio), was associated with lower incidence of both acute and chronic graft-versus-host disease (GVHD) and more than double the rate of GVHD-free and relapse-free survival, compared with the current standard of care for patients undergoing hematopoietic stem cell transplants (HSCT), investigators said.

In both a multicenter phase 1 trial (NCT04013685) and single-center phase 1/2 trial (NCT01660607) with a total of 50 patients, those who received Orca-T with single-agent GVHD prophylaxis had a 1-year GVHD-free and relapse-free survival rate of 75%, compared with 31% for patients who received standard of care with two-agent prophylaxis, reported Everett H. Meyer, MD, PhD, from the Stanford (Calif.) University.

“Orca-T has good evidence for reduced acute graft-versus-host disease, reduced chromic graft-versus-host disease, and a low nonrelapse mortality,” he said at the Transplant & Cellular Therapies Meetings.

The product can be quickly manufactured and delivered to treatment centers across the continental United States, with “vein-to-vein” time of less than 72 hours, he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Orca-T consists of highly purified, donor-derived T-regulatory (Treg) cells that are sorted and delivered on day 0 with hematopoietic stem cells, without immunosuppressants, followed 2 days later with infusion of a matching dose of conventional T cells.

“The Treg cells are allowed to expand to create the right microenvironment for the [conventional T cells],” he explained.

In preclinical studies, donor-derived, high-purity Tregs delivered prior to adoptive transfer of conventional T cells prevented GVHD while maintaining graft-versus-tumor immunity, he said.
 

Two T-cell infusions

He reported updated results from current studies on a total of 50 adults, with a cohort of 144 patients treated concurrently with standard of care as controls.

The Orca-T–treated patients had a median age of 47 and 52% were male. Indications for transplant included acute myeloid and acute lymphoblastic leukemia, chronic myeloid leukemia, B-cell lymphoma, myelodysplastic syndrome/myelofibrosis, and other unspecified indications.

In both the Orca-T and control cohorts, patients underwent myeloablative conditioning from 10 to 2 days prior to stem cell infusion.

As noted patients in the experimental arm received infusion of hematopoietic stem/progenitor cells and Tregs, followed 2 days later by conventional T-cell infusion, and, on the day after that, tacrolimus at a target dose of 4.6 ng/mL. The conventional T cells were reserved from donor apheresis and were otherwise unmanipulated prior to infusion into the recipient, Dr. Meyer noted.

Patients in the standard-of-care arm received tacrolimus on the day before standard infusion of the apheresis product, followed by methotrexate prophylaxis on days 1, 3, 6 and 11.

Time to neutrophil engraftment, platelet engraftment, and from day 0 to hospital discharge were all significantly shorter in the Orca-T group, at 12 versus 14 days (P < .0001), 11 vs. 17 days (P < .0001), and 15 vs. 17 days (P = .01) respectively.

At 100 days of follow-up, the rate of grade 2 or greater acute GVHD was 30% among standard-of-care patients versus 10% among Orca-T–treated patients. At 1-year follow-up, respective rates of chronic GVHD were 46% vs. 3%.
 

Safety

“In general, the protocol is extremely well tolerated by our patients. We’ve seen no exceptional infectious disease complications, and we’ve seen no other major complications,” Dr. Meyer said.

Cytomegalovirus prophylaxis was used variably, depending on the center and on the attending physician. Epstein-Barr virus reactivation occurred in eight patients, with one requiring therapy, but there was no biopsy or radiographic evidence of posttransplant lymphoproliferative disorder.

In all, 18% of patients had serious adverse events during the reporting period, all of which resolved. There were no treatment-related deaths in the Orca-T arm, compared with 11% of controls.
 

Engraftment differences explored

In the question-and-answer session following the presentation, Christopher J. Gamper, MD, PhD, from the Johns Hopkins Hospital in Baltimore, told Dr. Meyer that “your outcomes from Orca-T look excellent,” and asked about the cost differential, compared with similar, unmanipulated transplants performed with standard GVHD prophylaxis.

“Is this recovered by lower costs for treatment of GVHD?” he asked.

“I have not done an economic cost analysis of course, and I think others may be looking into this,” Dr. Meyer replied. “Graft engineering can be expensive, although it’s an engineering proposition and one could imagine that the costs will go down substantially over time.”

Session moderator Alan Hanash, MD, PhD, from Memorial Sloan Kettering Cancer Center in New York, commented on the differences in engraftment between the experimental controls arms, and asked Dr. Meyer: “Do you think this is due to the difference in prophylaxis? Absence of methotrexate? Do you think that it could be a direct impact of regulatory T cells on hematopoietic engraftment?”

“Certainly not having methotrexate is beneficial for engraftment, and may account for the differences we see, Dr. Meyer said. “However, it is possible that Tregs could be playing a facilitative role. There certainly is good preclinical literature that Tregs, particularly in the bone marrow space, can facilitate bone marrow engraftment.”

The Orca-T trials are sponsored by Orca Bio and Stanford, with support from the National Institutes of Health. Dr. Meyer receives research support from Orca and is a scientific adviser to GigaGen, Triursus, Incyte, and Indee Labs. Dr. Hanash and Dr. Gamper had no relevant disclosures.

A novel T-cell engineered product, Orca-T (Orca Bio), was associated with lower incidence of both acute and chronic graft-versus-host disease (GVHD) and more than double the rate of GVHD-free and relapse-free survival, compared with the current standard of care for patients undergoing hematopoietic stem cell transplants (HSCT), investigators said.

In both a multicenter phase 1 trial (NCT04013685) and single-center phase 1/2 trial (NCT01660607) with a total of 50 patients, those who received Orca-T with single-agent GVHD prophylaxis had a 1-year GVHD-free and relapse-free survival rate of 75%, compared with 31% for patients who received standard of care with two-agent prophylaxis, reported Everett H. Meyer, MD, PhD, from the Stanford (Calif.) University.

“Orca-T has good evidence for reduced acute graft-versus-host disease, reduced chromic graft-versus-host disease, and a low nonrelapse mortality,” he said at the Transplant & Cellular Therapies Meetings.

The product can be quickly manufactured and delivered to treatment centers across the continental United States, with “vein-to-vein” time of less than 72 hours, he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Orca-T consists of highly purified, donor-derived T-regulatory (Treg) cells that are sorted and delivered on day 0 with hematopoietic stem cells, without immunosuppressants, followed 2 days later with infusion of a matching dose of conventional T cells.

“The Treg cells are allowed to expand to create the right microenvironment for the [conventional T cells],” he explained.

In preclinical studies, donor-derived, high-purity Tregs delivered prior to adoptive transfer of conventional T cells prevented GVHD while maintaining graft-versus-tumor immunity, he said.
 

Two T-cell infusions

He reported updated results from current studies on a total of 50 adults, with a cohort of 144 patients treated concurrently with standard of care as controls.

The Orca-T–treated patients had a median age of 47 and 52% were male. Indications for transplant included acute myeloid and acute lymphoblastic leukemia, chronic myeloid leukemia, B-cell lymphoma, myelodysplastic syndrome/myelofibrosis, and other unspecified indications.

In both the Orca-T and control cohorts, patients underwent myeloablative conditioning from 10 to 2 days prior to stem cell infusion.

As noted patients in the experimental arm received infusion of hematopoietic stem/progenitor cells and Tregs, followed 2 days later by conventional T-cell infusion, and, on the day after that, tacrolimus at a target dose of 4.6 ng/mL. The conventional T cells were reserved from donor apheresis and were otherwise unmanipulated prior to infusion into the recipient, Dr. Meyer noted.

Patients in the standard-of-care arm received tacrolimus on the day before standard infusion of the apheresis product, followed by methotrexate prophylaxis on days 1, 3, 6 and 11.

Time to neutrophil engraftment, platelet engraftment, and from day 0 to hospital discharge were all significantly shorter in the Orca-T group, at 12 versus 14 days (P < .0001), 11 vs. 17 days (P < .0001), and 15 vs. 17 days (P = .01) respectively.

At 100 days of follow-up, the rate of grade 2 or greater acute GVHD was 30% among standard-of-care patients versus 10% among Orca-T–treated patients. At 1-year follow-up, respective rates of chronic GVHD were 46% vs. 3%.
 

Safety

“In general, the protocol is extremely well tolerated by our patients. We’ve seen no exceptional infectious disease complications, and we’ve seen no other major complications,” Dr. Meyer said.

Cytomegalovirus prophylaxis was used variably, depending on the center and on the attending physician. Epstein-Barr virus reactivation occurred in eight patients, with one requiring therapy, but there was no biopsy or radiographic evidence of posttransplant lymphoproliferative disorder.

In all, 18% of patients had serious adverse events during the reporting period, all of which resolved. There were no treatment-related deaths in the Orca-T arm, compared with 11% of controls.
 

Engraftment differences explored

In the question-and-answer session following the presentation, Christopher J. Gamper, MD, PhD, from the Johns Hopkins Hospital in Baltimore, told Dr. Meyer that “your outcomes from Orca-T look excellent,” and asked about the cost differential, compared with similar, unmanipulated transplants performed with standard GVHD prophylaxis.

“Is this recovered by lower costs for treatment of GVHD?” he asked.

“I have not done an economic cost analysis of course, and I think others may be looking into this,” Dr. Meyer replied. “Graft engineering can be expensive, although it’s an engineering proposition and one could imagine that the costs will go down substantially over time.”

Session moderator Alan Hanash, MD, PhD, from Memorial Sloan Kettering Cancer Center in New York, commented on the differences in engraftment between the experimental controls arms, and asked Dr. Meyer: “Do you think this is due to the difference in prophylaxis? Absence of methotrexate? Do you think that it could be a direct impact of regulatory T cells on hematopoietic engraftment?”

“Certainly not having methotrexate is beneficial for engraftment, and may account for the differences we see, Dr. Meyer said. “However, it is possible that Tregs could be playing a facilitative role. There certainly is good preclinical literature that Tregs, particularly in the bone marrow space, can facilitate bone marrow engraftment.”

The Orca-T trials are sponsored by Orca Bio and Stanford, with support from the National Institutes of Health. Dr. Meyer receives research support from Orca and is a scientific adviser to GigaGen, Triursus, Incyte, and Indee Labs. Dr. Hanash and Dr. Gamper had no relevant disclosures.

A novel T-cell engineered product, Orca-T (Orca Bio), was associated with lower incidence of both acute and chronic graft-versus-host disease (GVHD) and more than double the rate of GVHD-free and relapse-free survival, compared with the current standard of care for patients undergoing hematopoietic stem cell transplants (HSCT), investigators said.

In both a multicenter phase 1 trial (NCT04013685) and single-center phase 1/2 trial (NCT01660607) with a total of 50 patients, those who received Orca-T with single-agent GVHD prophylaxis had a 1-year GVHD-free and relapse-free survival rate of 75%, compared with 31% for patients who received standard of care with two-agent prophylaxis, reported Everett H. Meyer, MD, PhD, from the Stanford (Calif.) University.

“Orca-T has good evidence for reduced acute graft-versus-host disease, reduced chromic graft-versus-host disease, and a low nonrelapse mortality,” he said at the Transplant & Cellular Therapies Meetings.

The product can be quickly manufactured and delivered to treatment centers across the continental United States, with “vein-to-vein” time of less than 72 hours, he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Orca-T consists of highly purified, donor-derived T-regulatory (Treg) cells that are sorted and delivered on day 0 with hematopoietic stem cells, without immunosuppressants, followed 2 days later with infusion of a matching dose of conventional T cells.

“The Treg cells are allowed to expand to create the right microenvironment for the [conventional T cells],” he explained.

In preclinical studies, donor-derived, high-purity Tregs delivered prior to adoptive transfer of conventional T cells prevented GVHD while maintaining graft-versus-tumor immunity, he said.
 

Two T-cell infusions

He reported updated results from current studies on a total of 50 adults, with a cohort of 144 patients treated concurrently with standard of care as controls.

The Orca-T–treated patients had a median age of 47 and 52% were male. Indications for transplant included acute myeloid and acute lymphoblastic leukemia, chronic myeloid leukemia, B-cell lymphoma, myelodysplastic syndrome/myelofibrosis, and other unspecified indications.

In both the Orca-T and control cohorts, patients underwent myeloablative conditioning from 10 to 2 days prior to stem cell infusion.

As noted patients in the experimental arm received infusion of hematopoietic stem/progenitor cells and Tregs, followed 2 days later by conventional T-cell infusion, and, on the day after that, tacrolimus at a target dose of 4.6 ng/mL. The conventional T cells were reserved from donor apheresis and were otherwise unmanipulated prior to infusion into the recipient, Dr. Meyer noted.

Patients in the standard-of-care arm received tacrolimus on the day before standard infusion of the apheresis product, followed by methotrexate prophylaxis on days 1, 3, 6 and 11.

Time to neutrophil engraftment, platelet engraftment, and from day 0 to hospital discharge were all significantly shorter in the Orca-T group, at 12 versus 14 days (P < .0001), 11 vs. 17 days (P < .0001), and 15 vs. 17 days (P = .01) respectively.

At 100 days of follow-up, the rate of grade 2 or greater acute GVHD was 30% among standard-of-care patients versus 10% among Orca-T–treated patients. At 1-year follow-up, respective rates of chronic GVHD were 46% vs. 3%.
 

Safety

“In general, the protocol is extremely well tolerated by our patients. We’ve seen no exceptional infectious disease complications, and we’ve seen no other major complications,” Dr. Meyer said.

Cytomegalovirus prophylaxis was used variably, depending on the center and on the attending physician. Epstein-Barr virus reactivation occurred in eight patients, with one requiring therapy, but there was no biopsy or radiographic evidence of posttransplant lymphoproliferative disorder.

In all, 18% of patients had serious adverse events during the reporting period, all of which resolved. There were no treatment-related deaths in the Orca-T arm, compared with 11% of controls.
 

Engraftment differences explored

In the question-and-answer session following the presentation, Christopher J. Gamper, MD, PhD, from the Johns Hopkins Hospital in Baltimore, told Dr. Meyer that “your outcomes from Orca-T look excellent,” and asked about the cost differential, compared with similar, unmanipulated transplants performed with standard GVHD prophylaxis.

“Is this recovered by lower costs for treatment of GVHD?” he asked.

“I have not done an economic cost analysis of course, and I think others may be looking into this,” Dr. Meyer replied. “Graft engineering can be expensive, although it’s an engineering proposition and one could imagine that the costs will go down substantially over time.”

Session moderator Alan Hanash, MD, PhD, from Memorial Sloan Kettering Cancer Center in New York, commented on the differences in engraftment between the experimental controls arms, and asked Dr. Meyer: “Do you think this is due to the difference in prophylaxis? Absence of methotrexate? Do you think that it could be a direct impact of regulatory T cells on hematopoietic engraftment?”

“Certainly not having methotrexate is beneficial for engraftment, and may account for the differences we see, Dr. Meyer said. “However, it is possible that Tregs could be playing a facilitative role. There certainly is good preclinical literature that Tregs, particularly in the bone marrow space, can facilitate bone marrow engraftment.”

The Orca-T trials are sponsored by Orca Bio and Stanford, with support from the National Institutes of Health. Dr. Meyer receives research support from Orca and is a scientific adviser to GigaGen, Triursus, Incyte, and Indee Labs. Dr. Hanash and Dr. Gamper had no relevant disclosures.

In a clinical trial comparing three graft-versus-host disease (GVHD)–prevention regimens in patients undergoing hematopoietic stem cell transplants, a calcineurin inhibitor (CNI)–free strategy using CD34-selected peripheral blood stem cells (PBSCs) was associated with a nearly twofold increase in transplant-related mortality, compared with either a different CNI-free regimen or tacrolimus plus methotrexate, investigators reported.

In the phase 3 Progress II trial, patients who received CD34-selected PBSCs without post-transplant immune suppression had a hazard ratio for death of 1.74 compared with patients who received T-cell depletion with posttransplant cyclophosphamide, and a HR of 1.78, compared with patients who received tacrolimus and methotrexate after a bone marrow graft, Miguel-Angel Perales , MD, from Memorial Sloan Kettering Cancer Center, New York, reported at the Transplant & Cellular Therapies Meetings.

“CD34 selection was associated with worse overall survival, which offset any benefit from lower rates of moderate to severe chronic GVHD,” he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Neither of the two CNI-free interventions were superior to tacrolimus/methotrexate with bone marrow–derived stem cells for preventing chronic GVHD, and there were no differences in the primary endpoint of chronic GVHD/relapse-free survival, Dr. Perales said.
 

T-cell depletion vs. CNI

The Progress II trial was designed to see whether either of two CNI-free, T-cell depletion approaches could improve chronic GVHD rates post transplant over a CNI-based regimen.

The investigators enrolled patients aged 65 years or younger with acute leukemia or myelodysplasia with fewer than 5% blasts and a HLA-matched related or unrelated donor.

The patients were randomly assigned to either bone marrow grafts with tacrolimus/methotrexate (118 patients), bone marrow with in vivo posttransplant cyclophosphamide (114), or PBSCs with ex vivo CD34-selected cells (114).

The primary endpoint of chronic GVHD/relapse-free survival (CRFS) was a time-to-event outcome defined as moderate to severe chronic GVHD according to National Institutes of Health consensus criteria, disease relapse or progression, or death from any cause.

As noted before, there were no between-arm differences in the primary CRFS endpoint, and in multivariate analysis controlling for donor type, patient characteristics, disease category and disease risk index, the only factor significantly predictive for CRFS was being aged 50 years or older.

The 2-year posttransplant survival rates were 61.6% in the CD34-selected arm, 76.7% in the posttransplant cyclophosphamide arm, and 74.2% in the tacrolimus/methotrexate arm.

As noted before, the HR for CRFS with CD34 versus tacrolimus/methotrexate was 1.74, and for CD34 versus cyclophosphamide was 1.78 (P = .02 for both comparisons). In contrast, there was no differe­nce in CRFS between posttransplant cyclophosphamide and tacrolimus/methotrexate.

Both relapse-free survival and transplant-related mortality were worse with the CD34-selected group, compared with the other two groups, but there were no significant differences among the arms in disease relapse.

Hematologic recovery was faster in the CD34 arm, but there were no significant differences in graft failure.

In addition, the incidence of grade II-IV acute GVHD was increased in the posttransplant cyclophosphamide group, compared with the other two, while chronic GVHD and moderate to severe chronic GVHD were reduced in the CD34 group.

There were no differences in quality of life measures among the groups, Dr. Perales said.
 

Practice changing?

In the question-and answer-session following the presentation, comoderator Sarah Nikiforow , MD, PhD, from the Dana-Farber Cancer Institute in Boston, who was not involved in the study, asked whether the trial results could be considered as practice changing for any centers that historically have done CD34 selection, or whether CD34 selection is still a viable approach to GVHD prophylaxis.

“That’s obviously a key question from the study, and a question that we’re asking ourselves,” Dr. Perales said. “I think the lesson that we took from this study as it pertains to CD34 selection is obviously the increased mortality, likely related to regimen toxicity, and I think the use of high-dose radiation is something that we have to reexamine.”

He said that his center is also considering whether to reduce antithymocyte globulin dosing, move it earlier in the process, and to use pharmokinetic-directed ATG as a possible means of decreasing nonrelapse mortality.

“I think it remains a useful platform for adoptive cell therapy, potentially targeting relapsed disease,” he added.

The study was supported by the National Heart, Lung, and Blood Institute. Dr. Perales disclosed advisory board activities and consulting for multiple companies, and receiving research funding for clinical trials from several more. Dr. Nikiforow disclosed a consulting/advisory role for Kite Pharma, and travel accommodations and expense from Celyad Oncology.

In a clinical trial comparing three graft-versus-host disease (GVHD)–prevention regimens in patients undergoing hematopoietic stem cell transplants, a calcineurin inhibitor (CNI)–free strategy using CD34-selected peripheral blood stem cells (PBSCs) was associated with a nearly twofold increase in transplant-related mortality, compared with either a different CNI-free regimen or tacrolimus plus methotrexate, investigators reported.

In the phase 3 Progress II trial, patients who received CD34-selected PBSCs without post-transplant immune suppression had a hazard ratio for death of 1.74 compared with patients who received T-cell depletion with posttransplant cyclophosphamide, and a HR of 1.78, compared with patients who received tacrolimus and methotrexate after a bone marrow graft, Miguel-Angel Perales , MD, from Memorial Sloan Kettering Cancer Center, New York, reported at the Transplant & Cellular Therapies Meetings.

“CD34 selection was associated with worse overall survival, which offset any benefit from lower rates of moderate to severe chronic GVHD,” he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Neither of the two CNI-free interventions were superior to tacrolimus/methotrexate with bone marrow–derived stem cells for preventing chronic GVHD, and there were no differences in the primary endpoint of chronic GVHD/relapse-free survival, Dr. Perales said.
 

T-cell depletion vs. CNI

The Progress II trial was designed to see whether either of two CNI-free, T-cell depletion approaches could improve chronic GVHD rates post transplant over a CNI-based regimen.

The investigators enrolled patients aged 65 years or younger with acute leukemia or myelodysplasia with fewer than 5% blasts and a HLA-matched related or unrelated donor.

The patients were randomly assigned to either bone marrow grafts with tacrolimus/methotrexate (118 patients), bone marrow with in vivo posttransplant cyclophosphamide (114), or PBSCs with ex vivo CD34-selected cells (114).

The primary endpoint of chronic GVHD/relapse-free survival (CRFS) was a time-to-event outcome defined as moderate to severe chronic GVHD according to National Institutes of Health consensus criteria, disease relapse or progression, or death from any cause.

As noted before, there were no between-arm differences in the primary CRFS endpoint, and in multivariate analysis controlling for donor type, patient characteristics, disease category and disease risk index, the only factor significantly predictive for CRFS was being aged 50 years or older.

The 2-year posttransplant survival rates were 61.6% in the CD34-selected arm, 76.7% in the posttransplant cyclophosphamide arm, and 74.2% in the tacrolimus/methotrexate arm.

As noted before, the HR for CRFS with CD34 versus tacrolimus/methotrexate was 1.74, and for CD34 versus cyclophosphamide was 1.78 (P = .02 for both comparisons). In contrast, there was no differe­nce in CRFS between posttransplant cyclophosphamide and tacrolimus/methotrexate.

Both relapse-free survival and transplant-related mortality were worse with the CD34-selected group, compared with the other two groups, but there were no significant differences among the arms in disease relapse.

Hematologic recovery was faster in the CD34 arm, but there were no significant differences in graft failure.

In addition, the incidence of grade II-IV acute GVHD was increased in the posttransplant cyclophosphamide group, compared with the other two, while chronic GVHD and moderate to severe chronic GVHD were reduced in the CD34 group.

There were no differences in quality of life measures among the groups, Dr. Perales said.
 

Practice changing?

In the question-and answer-session following the presentation, comoderator Sarah Nikiforow , MD, PhD, from the Dana-Farber Cancer Institute in Boston, who was not involved in the study, asked whether the trial results could be considered as practice changing for any centers that historically have done CD34 selection, or whether CD34 selection is still a viable approach to GVHD prophylaxis.

“That’s obviously a key question from the study, and a question that we’re asking ourselves,” Dr. Perales said. “I think the lesson that we took from this study as it pertains to CD34 selection is obviously the increased mortality, likely related to regimen toxicity, and I think the use of high-dose radiation is something that we have to reexamine.”

He said that his center is also considering whether to reduce antithymocyte globulin dosing, move it earlier in the process, and to use pharmokinetic-directed ATG as a possible means of decreasing nonrelapse mortality.

“I think it remains a useful platform for adoptive cell therapy, potentially targeting relapsed disease,” he added.

The study was supported by the National Heart, Lung, and Blood Institute. Dr. Perales disclosed advisory board activities and consulting for multiple companies, and receiving research funding for clinical trials from several more. Dr. Nikiforow disclosed a consulting/advisory role for Kite Pharma, and travel accommodations and expense from Celyad Oncology.

In a clinical trial comparing three graft-versus-host disease (GVHD)–prevention regimens in patients undergoing hematopoietic stem cell transplants, a calcineurin inhibitor (CNI)–free strategy using CD34-selected peripheral blood stem cells (PBSCs) was associated with a nearly twofold increase in transplant-related mortality, compared with either a different CNI-free regimen or tacrolimus plus methotrexate, investigators reported.

In the phase 3 Progress II trial, patients who received CD34-selected PBSCs without post-transplant immune suppression had a hazard ratio for death of 1.74 compared with patients who received T-cell depletion with posttransplant cyclophosphamide, and a HR of 1.78, compared with patients who received tacrolimus and methotrexate after a bone marrow graft, Miguel-Angel Perales , MD, from Memorial Sloan Kettering Cancer Center, New York, reported at the Transplant & Cellular Therapies Meetings.

“CD34 selection was associated with worse overall survival, which offset any benefit from lower rates of moderate to severe chronic GVHD,” he said at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Neither of the two CNI-free interventions were superior to tacrolimus/methotrexate with bone marrow–derived stem cells for preventing chronic GVHD, and there were no differences in the primary endpoint of chronic GVHD/relapse-free survival, Dr. Perales said.
 

T-cell depletion vs. CNI

The Progress II trial was designed to see whether either of two CNI-free, T-cell depletion approaches could improve chronic GVHD rates post transplant over a CNI-based regimen.

The investigators enrolled patients aged 65 years or younger with acute leukemia or myelodysplasia with fewer than 5% blasts and a HLA-matched related or unrelated donor.

The patients were randomly assigned to either bone marrow grafts with tacrolimus/methotrexate (118 patients), bone marrow with in vivo posttransplant cyclophosphamide (114), or PBSCs with ex vivo CD34-selected cells (114).

The primary endpoint of chronic GVHD/relapse-free survival (CRFS) was a time-to-event outcome defined as moderate to severe chronic GVHD according to National Institutes of Health consensus criteria, disease relapse or progression, or death from any cause.

As noted before, there were no between-arm differences in the primary CRFS endpoint, and in multivariate analysis controlling for donor type, patient characteristics, disease category and disease risk index, the only factor significantly predictive for CRFS was being aged 50 years or older.

The 2-year posttransplant survival rates were 61.6% in the CD34-selected arm, 76.7% in the posttransplant cyclophosphamide arm, and 74.2% in the tacrolimus/methotrexate arm.

As noted before, the HR for CRFS with CD34 versus tacrolimus/methotrexate was 1.74, and for CD34 versus cyclophosphamide was 1.78 (P = .02 for both comparisons). In contrast, there was no differe­nce in CRFS between posttransplant cyclophosphamide and tacrolimus/methotrexate.

Both relapse-free survival and transplant-related mortality were worse with the CD34-selected group, compared with the other two groups, but there were no significant differences among the arms in disease relapse.

Hematologic recovery was faster in the CD34 arm, but there were no significant differences in graft failure.

In addition, the incidence of grade II-IV acute GVHD was increased in the posttransplant cyclophosphamide group, compared with the other two, while chronic GVHD and moderate to severe chronic GVHD were reduced in the CD34 group.

There were no differences in quality of life measures among the groups, Dr. Perales said.
 

Practice changing?

In the question-and answer-session following the presentation, comoderator Sarah Nikiforow , MD, PhD, from the Dana-Farber Cancer Institute in Boston, who was not involved in the study, asked whether the trial results could be considered as practice changing for any centers that historically have done CD34 selection, or whether CD34 selection is still a viable approach to GVHD prophylaxis.

“That’s obviously a key question from the study, and a question that we’re asking ourselves,” Dr. Perales said. “I think the lesson that we took from this study as it pertains to CD34 selection is obviously the increased mortality, likely related to regimen toxicity, and I think the use of high-dose radiation is something that we have to reexamine.”

He said that his center is also considering whether to reduce antithymocyte globulin dosing, move it earlier in the process, and to use pharmokinetic-directed ATG as a possible means of decreasing nonrelapse mortality.

“I think it remains a useful platform for adoptive cell therapy, potentially targeting relapsed disease,” he added.

The study was supported by the National Heart, Lung, and Blood Institute. Dr. Perales disclosed advisory board activities and consulting for multiple companies, and receiving research funding for clinical trials from several more. Dr. Nikiforow disclosed a consulting/advisory role for Kite Pharma, and travel accommodations and expense from Celyad Oncology.

Steroids are usually the first choice of therapy for the treatment of patients with graft-vs.-host disease (GVHD), but complications from steroid use may carry a high financial cost, investigators caution.

Among 689 patients with a diagnosis of GVHD following a hematopoietic stem cell transplant (HSCT) who received steroids, 685 (97%) had at least one steroid-related complication, resulting in nearly $165,000 in mean health-care costs over 24 months, said Elizabeth J. Bell, PhD, MPH, an epidemiologist at Optum Inc.

“For both acute and chronic GVHD, the standard of care for first-line treatment is systemic steroids. The complications associated with steroid treatment are well known. However, the health-care resources utilized and the costs incurred by these patients are not well-quantified,” she said at the Transplantation & Cellular Therapies Meetings (Abstract 12).

Dr. Bell reported the results of a retrospective database analysis on costs associated with steroid complications in HSCT recipients at the meeting, which was held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

She and colleagues from Optum, Incyte, and the University of Minnesota in Minneapolis looked at data on 689 patients with a diagnosis of GVHD after HSCT who received systemic steroids from July 1, 2010, through Aug. 31, 2019. The data were extracted from the Optum Research database, and included U.S. commercial and Medicare Advantage patients.

They looked at total complications and steroid-associated complications in each of four categories: infections; metabolic or endocrine complications (for example, diabetes, dyslipidemia); gastrointestinal (GI) complications (e.g., peptic ulcer disease); and bone or muscle complications (myopathy, etc).

They estimated costs based on International Classification of Diseases (ICD) codes for any steroid complications during the 24 months after steroid initiation, including those complications that may have been present at the time of GVHD diagnosis.

The median patient age was 55 years, and 60% of the sample were male. The mean Charlson Comorbidity Index score at baseline was 3.

Overall, 22% of patients had only acute GVHD, 21% had only chronic GVHD, and 39% had both acute and chronic disease. The GVHD type was unspecified in the remaining 18%.

The median time from GVHD diagnosis to initiating steroids was 30 days for patients with both acute and chronic disease, as well as those with both presentations. The median time to initiation was 36 days for patients with unspecified GVHD type.

The median cumulative duration of steroid use over 24 months was 62 days for patients with acute GVHD, 208 days for those with chronic GVHD, 166 days for those with both, and 74 days for patients with unspecified GVHD type.

As noted before, complications occurred in 97% of patients, with infections being the most common complications, occurring in 80% of patients, followed by metabolic/endocrine complications in 32%, gastrointestinal in 29%, and bone/muscle complications in 20%.

For the 665 patients who had any steroid-related complication, the mean costs of steroid-associated care in the 24 months after they were started on steroids was $164,787, and the median cost was $50,834.

Health care costs were highest among patients with infections, at a mean of $167,473, and a median of $57,680, followed by bone/muscle conditions ($75,289 and $2,057, respectively), GI conditions ($67,861 and $3,360), and metabolic or endocrine conditions ($47, 101 and $1,164).

In all categories, hospitalizations accounted for the large majority of costs.

Two-thirds (66%) of patients who experienced any steroid-related complication required hospitalization, primarily for infections.

Among all patients with complications, the median cumulative hospital stay over 24 months was 20 days, with bone/muscle complications and infections associated with a median of 19 and 18 days of hospitalization, respectively.

Dr. Bell acknowledged that the study was limited by use of ICD coding to identify steroid complication-related health-care utilization and costs, which can be imprecise, and by the fact that the analysis included only complications resulting in health care use as documented in medical claims. In addition, the investigators noted that they could not control for the possibility that steroids exacerbated conditions that existed at baseline.

“These findings emphasize the need to cautiously evaluate the treatment options for patients with GVHD. Future study with medical records is needed to provide insights on the clinical aspects of the complications (e.g., severity and suspected causality),” Dr. Bell and colleagues concluded in the study’s abstract.
 

Definitions questioned

An HSCT specialist approached for comment said that the findings of the study made sense, but she had questions regarding the study methodology.

“I would intuitively think that steroid-associated complications are a major cause of health care use in GVHD patients and it’s interesting to see that there is emerging data to support this hypothesis,” HSCT specialist Hélène Schoemans, MD of the University of Leuven, Belgium, said in an interview.

She noted, however, that “it is surprising that the period of steroid initiation was the same for acute and chronic GVHD,” and questioned whether that anomalous finding could be due to the study’s definition of acute and chronic GVHD or to how the period from baseline to steroid initiation was defined.

The questions about the definitions and timing of therapy make it uncertain as to whether the complications reported were caused by steroids or by some other factor, she suggested.

The study was supported by Optum Inc. Dr. Bell is an employee of the company, and a paid consultant of Incyte. Dr. Schoemans has received travel expenses from Celgene, Abbvie, and Incyte; is part of the advisory boards for Incyte; and has received speakers fees from Novartis, Incyte, Jazz Pharmaceuticals, and Takeda.

Steroids are usually the first choice of therapy for the treatment of patients with graft-vs.-host disease (GVHD), but complications from steroid use may carry a high financial cost, investigators caution.

Among 689 patients with a diagnosis of GVHD following a hematopoietic stem cell transplant (HSCT) who received steroids, 685 (97%) had at least one steroid-related complication, resulting in nearly $165,000 in mean health-care costs over 24 months, said Elizabeth J. Bell, PhD, MPH, an epidemiologist at Optum Inc.

“For both acute and chronic GVHD, the standard of care for first-line treatment is systemic steroids. The complications associated with steroid treatment are well known. However, the health-care resources utilized and the costs incurred by these patients are not well-quantified,” she said at the Transplantation & Cellular Therapies Meetings (Abstract 12).

Dr. Bell reported the results of a retrospective database analysis on costs associated with steroid complications in HSCT recipients at the meeting, which was held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

She and colleagues from Optum, Incyte, and the University of Minnesota in Minneapolis looked at data on 689 patients with a diagnosis of GVHD after HSCT who received systemic steroids from July 1, 2010, through Aug. 31, 2019. The data were extracted from the Optum Research database, and included U.S. commercial and Medicare Advantage patients.

They looked at total complications and steroid-associated complications in each of four categories: infections; metabolic or endocrine complications (for example, diabetes, dyslipidemia); gastrointestinal (GI) complications (e.g., peptic ulcer disease); and bone or muscle complications (myopathy, etc).

They estimated costs based on International Classification of Diseases (ICD) codes for any steroid complications during the 24 months after steroid initiation, including those complications that may have been present at the time of GVHD diagnosis.

The median patient age was 55 years, and 60% of the sample were male. The mean Charlson Comorbidity Index score at baseline was 3.

Overall, 22% of patients had only acute GVHD, 21% had only chronic GVHD, and 39% had both acute and chronic disease. The GVHD type was unspecified in the remaining 18%.

The median time from GVHD diagnosis to initiating steroids was 30 days for patients with both acute and chronic disease, as well as those with both presentations. The median time to initiation was 36 days for patients with unspecified GVHD type.

The median cumulative duration of steroid use over 24 months was 62 days for patients with acute GVHD, 208 days for those with chronic GVHD, 166 days for those with both, and 74 days for patients with unspecified GVHD type.

As noted before, complications occurred in 97% of patients, with infections being the most common complications, occurring in 80% of patients, followed by metabolic/endocrine complications in 32%, gastrointestinal in 29%, and bone/muscle complications in 20%.

For the 665 patients who had any steroid-related complication, the mean costs of steroid-associated care in the 24 months after they were started on steroids was $164,787, and the median cost was $50,834.

Health care costs were highest among patients with infections, at a mean of $167,473, and a median of $57,680, followed by bone/muscle conditions ($75,289 and $2,057, respectively), GI conditions ($67,861 and $3,360), and metabolic or endocrine conditions ($47, 101 and $1,164).

In all categories, hospitalizations accounted for the large majority of costs.

Two-thirds (66%) of patients who experienced any steroid-related complication required hospitalization, primarily for infections.

Among all patients with complications, the median cumulative hospital stay over 24 months was 20 days, with bone/muscle complications and infections associated with a median of 19 and 18 days of hospitalization, respectively.

Dr. Bell acknowledged that the study was limited by use of ICD coding to identify steroid complication-related health-care utilization and costs, which can be imprecise, and by the fact that the analysis included only complications resulting in health care use as documented in medical claims. In addition, the investigators noted that they could not control for the possibility that steroids exacerbated conditions that existed at baseline.

“These findings emphasize the need to cautiously evaluate the treatment options for patients with GVHD. Future study with medical records is needed to provide insights on the clinical aspects of the complications (e.g., severity and suspected causality),” Dr. Bell and colleagues concluded in the study’s abstract.
 

Definitions questioned

An HSCT specialist approached for comment said that the findings of the study made sense, but she had questions regarding the study methodology.

“I would intuitively think that steroid-associated complications are a major cause of health care use in GVHD patients and it’s interesting to see that there is emerging data to support this hypothesis,” HSCT specialist Hélène Schoemans, MD of the University of Leuven, Belgium, said in an interview.

She noted, however, that “it is surprising that the period of steroid initiation was the same for acute and chronic GVHD,” and questioned whether that anomalous finding could be due to the study’s definition of acute and chronic GVHD or to how the period from baseline to steroid initiation was defined.

The questions about the definitions and timing of therapy make it uncertain as to whether the complications reported were caused by steroids or by some other factor, she suggested.

The study was supported by Optum Inc. Dr. Bell is an employee of the company, and a paid consultant of Incyte. Dr. Schoemans has received travel expenses from Celgene, Abbvie, and Incyte; is part of the advisory boards for Incyte; and has received speakers fees from Novartis, Incyte, Jazz Pharmaceuticals, and Takeda.

Steroids are usually the first choice of therapy for the treatment of patients with graft-vs.-host disease (GVHD), but complications from steroid use may carry a high financial cost, investigators caution.

Among 689 patients with a diagnosis of GVHD following a hematopoietic stem cell transplant (HSCT) who received steroids, 685 (97%) had at least one steroid-related complication, resulting in nearly $165,000 in mean health-care costs over 24 months, said Elizabeth J. Bell, PhD, MPH, an epidemiologist at Optum Inc.

“For both acute and chronic GVHD, the standard of care for first-line treatment is systemic steroids. The complications associated with steroid treatment are well known. However, the health-care resources utilized and the costs incurred by these patients are not well-quantified,” she said at the Transplantation & Cellular Therapies Meetings (Abstract 12).

Dr. Bell reported the results of a retrospective database analysis on costs associated with steroid complications in HSCT recipients at the meeting, which was held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

She and colleagues from Optum, Incyte, and the University of Minnesota in Minneapolis looked at data on 689 patients with a diagnosis of GVHD after HSCT who received systemic steroids from July 1, 2010, through Aug. 31, 2019. The data were extracted from the Optum Research database, and included U.S. commercial and Medicare Advantage patients.

They looked at total complications and steroid-associated complications in each of four categories: infections; metabolic or endocrine complications (for example, diabetes, dyslipidemia); gastrointestinal (GI) complications (e.g., peptic ulcer disease); and bone or muscle complications (myopathy, etc).

They estimated costs based on International Classification of Diseases (ICD) codes for any steroid complications during the 24 months after steroid initiation, including those complications that may have been present at the time of GVHD diagnosis.

The median patient age was 55 years, and 60% of the sample were male. The mean Charlson Comorbidity Index score at baseline was 3.

Overall, 22% of patients had only acute GVHD, 21% had only chronic GVHD, and 39% had both acute and chronic disease. The GVHD type was unspecified in the remaining 18%.

The median time from GVHD diagnosis to initiating steroids was 30 days for patients with both acute and chronic disease, as well as those with both presentations. The median time to initiation was 36 days for patients with unspecified GVHD type.

The median cumulative duration of steroid use over 24 months was 62 days for patients with acute GVHD, 208 days for those with chronic GVHD, 166 days for those with both, and 74 days for patients with unspecified GVHD type.

As noted before, complications occurred in 97% of patients, with infections being the most common complications, occurring in 80% of patients, followed by metabolic/endocrine complications in 32%, gastrointestinal in 29%, and bone/muscle complications in 20%.

For the 665 patients who had any steroid-related complication, the mean costs of steroid-associated care in the 24 months after they were started on steroids was $164,787, and the median cost was $50,834.

Health care costs were highest among patients with infections, at a mean of $167,473, and a median of $57,680, followed by bone/muscle conditions ($75,289 and $2,057, respectively), GI conditions ($67,861 and $3,360), and metabolic or endocrine conditions ($47, 101 and $1,164).

In all categories, hospitalizations accounted for the large majority of costs.

Two-thirds (66%) of patients who experienced any steroid-related complication required hospitalization, primarily for infections.

Among all patients with complications, the median cumulative hospital stay over 24 months was 20 days, with bone/muscle complications and infections associated with a median of 19 and 18 days of hospitalization, respectively.

Dr. Bell acknowledged that the study was limited by use of ICD coding to identify steroid complication-related health-care utilization and costs, which can be imprecise, and by the fact that the analysis included only complications resulting in health care use as documented in medical claims. In addition, the investigators noted that they could not control for the possibility that steroids exacerbated conditions that existed at baseline.

“These findings emphasize the need to cautiously evaluate the treatment options for patients with GVHD. Future study with medical records is needed to provide insights on the clinical aspects of the complications (e.g., severity and suspected causality),” Dr. Bell and colleagues concluded in the study’s abstract.
 

Definitions questioned

An HSCT specialist approached for comment said that the findings of the study made sense, but she had questions regarding the study methodology.

“I would intuitively think that steroid-associated complications are a major cause of health care use in GVHD patients and it’s interesting to see that there is emerging data to support this hypothesis,” HSCT specialist Hélène Schoemans, MD of the University of Leuven, Belgium, said in an interview.

She noted, however, that “it is surprising that the period of steroid initiation was the same for acute and chronic GVHD,” and questioned whether that anomalous finding could be due to the study’s definition of acute and chronic GVHD or to how the period from baseline to steroid initiation was defined.

The questions about the definitions and timing of therapy make it uncertain as to whether the complications reported were caused by steroids or by some other factor, she suggested.

The study was supported by Optum Inc. Dr. Bell is an employee of the company, and a paid consultant of Incyte. Dr. Schoemans has received travel expenses from Celgene, Abbvie, and Incyte; is part of the advisory boards for Incyte; and has received speakers fees from Novartis, Incyte, Jazz Pharmaceuticals, and Takeda.

Despite improvements in prevention of graft-versus-host disease, chronic GVHD still occurs in 10%-50% of patients who undergo an allogeneic hematopoietic stem cell transplant, and these patients may require prolonged treatment with multiple lines of therapy, said a hematologist and transplant researcher.

“More effective, less toxic therapies for chronic GVHD are needed,” Stephanie Lee, MD, MPH, from the Fred Hutchinson Cancer Research Center in Seattle said at the Transplant & Cellular Therapies Meetings.

Dr. Lee reviewed clinical trials for chronic GVHD at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Although the incidence of chronic GVHD has gradually declined over the last 40 years and both relapse-free and overall survival following a chronic GVHD diagnosis have improved, “for patients who are diagnosed with chronic GVHD, they still will see many lines of therapy and many years of therapy,” she said.

Among 148 patients with chronic GVHD treated at her center, for example, 66% went on to two lines of therapy, 50% went on to three lines, 37% required four lines of therapy, and 20% needed five lines or more.

Salvage therapies for patients with chronic GVHD have evolved away from immunomodulators and immunosuppressants in the early 1990s, toward monoclonal antibodies such as rituximab in the early 2000s, to interleukin-2 and to tyrosine kinase inhibitors such as ruxolitinib (Jakafi) and ibrutinib (Imbruvica).

There are currently 36 agents that are FDA approved for at least one indication and can also be prescribed for the treatment of chronic GVHD, Dr. Lee noted.
 

Treatment goals

Dr. Lee laid out six goals for treating patients with chronic GVHD. They include:

• Controlling current signs and symptoms, measured by response rates and patient-reported outcomes
• Preventing further tissue and organ damage
• Minimizing toxicity
• Maintaining graft-versus-tumor effect
• Achieving graft tolerance and stopping immunosuppression
• Decreasing nonrelapse mortality and improving survival

Active trials

Dr. Lee identified 33 trials with chronic GVHD as an indication that are currently recruiting, and an additional 13 trials that are active but closed to recruiting. The trials can be generally grouped by mechanism of action, and involve agents targeting T-regulatory cells, B cells and/or B-cell receptor (BCR) signaling, monocytes/macrophages, costimulatory blockage, a proteasome inhibition, Janus kinase (JAK) 1/2 inhibitors, ROCK2 inhibitors, hedgehog pathway inhibition, cellular therapy, and organ-targeted therapy.

Most of the trials have overall response rate as the primary endpoint, and all but five are currently in phase 1 or 2. The currently active phase 3 trials include two with ibrutinib, one with the investigational agent itacitinib, one with ruxolitinib, and one with mesenchymal stem cells.

“I’ll note that, when results are reported, the denominator really matters for the overall response rate, especially if you’re talking about small trials, because if you require the patient to be treated with an agent for a certain period of time, and you take out all the people who didn’t make it to that time point, then your overall response rate looks better,” she said.
 

BTK inhibitors

The first-in-class Bruton tyrosine kinase (BTK) inhibitor ibrutinib was the first and thus far only agent approved by the Food and Drug Administration for chronic GVHD. The approval was based on a single-arm, multicenter trial with 42 patients.

The ORR in this trial was 69%, consisting of 31% complete responses and 38% partial responses, with a duration of response longer than 10 months in slightly more than half of all patients. In all, 24% of patients had improvement of symptoms in two consecutive visits, and 29% continued on ibrutinib at the time of the primary analysis in 2017.

Based on these promising results, acalabrutinib, which is more potent and selective for BTK than ibrutinib, with no effect on either platelets or natural killer cells, is currently under investigation in a phase 2 trial in 50 patients at a dose of 100 mg orally twice daily.
 

JAK1/2 inhibition

The JAK1 inhibitor itacitinib failed to meet its primary ORR endpoint in the phase 3 GRAVITAS-301 study, according to a press release, but the manufacturer (Incyte) said that it is continuing its commitment to JAK inhibitors with ruxolitinib, which has shown activity against acute, steroid-refractory GVHD, and is being explored for prevention of chronic GVHD in the randomized, phase 3 REACH3 study.

The trial met its primary endpoint for a higher ORR at week 24 with ruxolitinib versus best available therapy, at 49.7% versus 25.6%, respectively, which translated into an odds ratio for response with the JAK inhibitor of 2.99 (P < .0001).
 

Selective T-cell expansion

Efavaleukin alfa is an IL-2-mutated protein (mutein), with a mutation in the IL-2RB-binding portion of IL-2 causing increased selectivity for regulatory T-cell expansion. It is bound to an IgG-Fc domain that is itself mutated, with reduced Fc receptor binding and IgG effector function to give it a longer half life. This agent is being studied in a phase 1/2 trial in a subcutaneous formulation delivered every 1 or 2 weeks to 68 patients.

Monocyte/macrophage depletion

Axatilimab is a high-affinity antibody targeting colony stimulating factor–1 receptor (CSF-1R) expressed on monocytes and macrophages. By blocking CSF-1R, it depletes circulation of nonclassical monocytes and prevents the differentiation and survival of M2 macrophages in tissue.

It is currently being investigated 30 patients in a phase 1/2 study in an intravenous formulation delivered over 30 minutes every 2-4 weeks.
 

Hedgehog pathway inhibition

There is evidence suggesting that hedgehog pathway inhibition can lessen fibrosis. Glasdegib (Daurismo) a potent selective oral inhibitor of the hedgehog signaling pathway, is approved for use with low-dose cytarabine for patients with newly diagnosed acute myeloid leukemia aged older than 75 years or have comorbidities precluding intensive chemotherapy.

This agent is associated with drug intolerance because of muscle spasms, dysgeusia, and alopecia, however.

The drug is currently in phase 1/2 at a dose of 50 mg orally per day in 20 patients.
 

ROCK2 inhibition

Belumosudil (formerly KD025) “appears to rebalance the immune system,” Dr. Lee said. Investigators think that the drug dampens an autoaggressive inflammatory response by selective inhibition of ROCK2.

This drug has been studied in a dose-escalation study and a phase 2 trial, in which 132 participants were randomized to receive belumosudil 200 mg either once or twice daily.

At a median follow-up of 8 months, the ORR with belumosudil 200 mg once and twice daily was 73% and 74%, respectively. Similar results were seen in patients who had previously received either ruxolitinib or ibrutinib. High response rates were seen in patients with severe chronic GVHD, involvement of four or more organs and a refractory response to their last line of therapy.
 

Hard-to-manage patients

“We’re very hopeful for many of these agents, but we have to acknowledge that there are still many management dilemmas, patients that we just don’t really know what to do with,” Dr. Lee said. “These include patients who have bad sclerosis and fasciitis, nonhealing skin ulcers, bronchiolitis obliterans, serositis that can be very difficult to manage, severe keratoconjunctivitis that can be eyesight threatening, nonhealing mouth ulcers, esophageal structures, and always patients who have frequent infections.

“We are hopeful that some these agents will be useful for our patients who have severe manifestations, but often the number of patients with these manifestations in the trials is too low to say something specific about them,” she added.
 

‘Exciting time’

“It’s an exciting time because there are a lot of different drugs that are being studied for chronic GVHD,” commented Betty Hamilton, MD, a hematologist/oncologist at the Cleveland Clinic.

“I think that where the field is going in terms of treatment is recognizing that chronic GVHD is a pretty heterogeneous disease, and we have to learn even more about the underlying biologic pathways to be able to determine which class of drugs to use and when,” she said in an interview.

She agreed with Dr. Lee that the goals of treating patients with chronic GVHD include improving symptoms and quality, preventing progression, ideally tapering patients off immunosuppression, and achieving a balance between preventing negative consequences of GVHD while maintain the benefits of a graft-versus-leukemia effect.

“In our center, drug choice is based on physician preference and comfort with how often they’ve used the drug, patients’ comorbidities, toxicities of the drug, and logistical considerations,” Dr. Hamilton said.

Dr. Lee disclosed consulting activities for Pfizer and Kadmon, travel and lodging from Amgen, and research funding from those companies and others. Dr. Hamilton disclosed consulting for Syndax and Incyte.

Despite improvements in prevention of graft-versus-host disease, chronic GVHD still occurs in 10%-50% of patients who undergo an allogeneic hematopoietic stem cell transplant, and these patients may require prolonged treatment with multiple lines of therapy, said a hematologist and transplant researcher.

“More effective, less toxic therapies for chronic GVHD are needed,” Stephanie Lee, MD, MPH, from the Fred Hutchinson Cancer Research Center in Seattle said at the Transplant & Cellular Therapies Meetings.

Dr. Lee reviewed clinical trials for chronic GVHD at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Although the incidence of chronic GVHD has gradually declined over the last 40 years and both relapse-free and overall survival following a chronic GVHD diagnosis have improved, “for patients who are diagnosed with chronic GVHD, they still will see many lines of therapy and many years of therapy,” she said.

Among 148 patients with chronic GVHD treated at her center, for example, 66% went on to two lines of therapy, 50% went on to three lines, 37% required four lines of therapy, and 20% needed five lines or more.

Salvage therapies for patients with chronic GVHD have evolved away from immunomodulators and immunosuppressants in the early 1990s, toward monoclonal antibodies such as rituximab in the early 2000s, to interleukin-2 and to tyrosine kinase inhibitors such as ruxolitinib (Jakafi) and ibrutinib (Imbruvica).

There are currently 36 agents that are FDA approved for at least one indication and can also be prescribed for the treatment of chronic GVHD, Dr. Lee noted.
 

Treatment goals

Dr. Lee laid out six goals for treating patients with chronic GVHD. They include:

• Controlling current signs and symptoms, measured by response rates and patient-reported outcomes
• Preventing further tissue and organ damage
• Minimizing toxicity
• Maintaining graft-versus-tumor effect
• Achieving graft tolerance and stopping immunosuppression
• Decreasing nonrelapse mortality and improving survival

Active trials

Dr. Lee identified 33 trials with chronic GVHD as an indication that are currently recruiting, and an additional 13 trials that are active but closed to recruiting. The trials can be generally grouped by mechanism of action, and involve agents targeting T-regulatory cells, B cells and/or B-cell receptor (BCR) signaling, monocytes/macrophages, costimulatory blockage, a proteasome inhibition, Janus kinase (JAK) 1/2 inhibitors, ROCK2 inhibitors, hedgehog pathway inhibition, cellular therapy, and organ-targeted therapy.

Most of the trials have overall response rate as the primary endpoint, and all but five are currently in phase 1 or 2. The currently active phase 3 trials include two with ibrutinib, one with the investigational agent itacitinib, one with ruxolitinib, and one with mesenchymal stem cells.

“I’ll note that, when results are reported, the denominator really matters for the overall response rate, especially if you’re talking about small trials, because if you require the patient to be treated with an agent for a certain period of time, and you take out all the people who didn’t make it to that time point, then your overall response rate looks better,” she said.
 

BTK inhibitors

The first-in-class Bruton tyrosine kinase (BTK) inhibitor ibrutinib was the first and thus far only agent approved by the Food and Drug Administration for chronic GVHD. The approval was based on a single-arm, multicenter trial with 42 patients.

The ORR in this trial was 69%, consisting of 31% complete responses and 38% partial responses, with a duration of response longer than 10 months in slightly more than half of all patients. In all, 24% of patients had improvement of symptoms in two consecutive visits, and 29% continued on ibrutinib at the time of the primary analysis in 2017.

Based on these promising results, acalabrutinib, which is more potent and selective for BTK than ibrutinib, with no effect on either platelets or natural killer cells, is currently under investigation in a phase 2 trial in 50 patients at a dose of 100 mg orally twice daily.
 

JAK1/2 inhibition

The JAK1 inhibitor itacitinib failed to meet its primary ORR endpoint in the phase 3 GRAVITAS-301 study, according to a press release, but the manufacturer (Incyte) said that it is continuing its commitment to JAK inhibitors with ruxolitinib, which has shown activity against acute, steroid-refractory GVHD, and is being explored for prevention of chronic GVHD in the randomized, phase 3 REACH3 study.

The trial met its primary endpoint for a higher ORR at week 24 with ruxolitinib versus best available therapy, at 49.7% versus 25.6%, respectively, which translated into an odds ratio for response with the JAK inhibitor of 2.99 (P < .0001).
 

Selective T-cell expansion

Efavaleukin alfa is an IL-2-mutated protein (mutein), with a mutation in the IL-2RB-binding portion of IL-2 causing increased selectivity for regulatory T-cell expansion. It is bound to an IgG-Fc domain that is itself mutated, with reduced Fc receptor binding and IgG effector function to give it a longer half life. This agent is being studied in a phase 1/2 trial in a subcutaneous formulation delivered every 1 or 2 weeks to 68 patients.

Monocyte/macrophage depletion

Axatilimab is a high-affinity antibody targeting colony stimulating factor–1 receptor (CSF-1R) expressed on monocytes and macrophages. By blocking CSF-1R, it depletes circulation of nonclassical monocytes and prevents the differentiation and survival of M2 macrophages in tissue.

It is currently being investigated 30 patients in a phase 1/2 study in an intravenous formulation delivered over 30 minutes every 2-4 weeks.
 

Hedgehog pathway inhibition

There is evidence suggesting that hedgehog pathway inhibition can lessen fibrosis. Glasdegib (Daurismo) a potent selective oral inhibitor of the hedgehog signaling pathway, is approved for use with low-dose cytarabine for patients with newly diagnosed acute myeloid leukemia aged older than 75 years or have comorbidities precluding intensive chemotherapy.

This agent is associated with drug intolerance because of muscle spasms, dysgeusia, and alopecia, however.

The drug is currently in phase 1/2 at a dose of 50 mg orally per day in 20 patients.
 

ROCK2 inhibition

Belumosudil (formerly KD025) “appears to rebalance the immune system,” Dr. Lee said. Investigators think that the drug dampens an autoaggressive inflammatory response by selective inhibition of ROCK2.

This drug has been studied in a dose-escalation study and a phase 2 trial, in which 132 participants were randomized to receive belumosudil 200 mg either once or twice daily.

At a median follow-up of 8 months, the ORR with belumosudil 200 mg once and twice daily was 73% and 74%, respectively. Similar results were seen in patients who had previously received either ruxolitinib or ibrutinib. High response rates were seen in patients with severe chronic GVHD, involvement of four or more organs and a refractory response to their last line of therapy.
 

Hard-to-manage patients

“We’re very hopeful for many of these agents, but we have to acknowledge that there are still many management dilemmas, patients that we just don’t really know what to do with,” Dr. Lee said. “These include patients who have bad sclerosis and fasciitis, nonhealing skin ulcers, bronchiolitis obliterans, serositis that can be very difficult to manage, severe keratoconjunctivitis that can be eyesight threatening, nonhealing mouth ulcers, esophageal structures, and always patients who have frequent infections.

“We are hopeful that some these agents will be useful for our patients who have severe manifestations, but often the number of patients with these manifestations in the trials is too low to say something specific about them,” she added.
 

‘Exciting time’

“It’s an exciting time because there are a lot of different drugs that are being studied for chronic GVHD,” commented Betty Hamilton, MD, a hematologist/oncologist at the Cleveland Clinic.

“I think that where the field is going in terms of treatment is recognizing that chronic GVHD is a pretty heterogeneous disease, and we have to learn even more about the underlying biologic pathways to be able to determine which class of drugs to use and when,” she said in an interview.

She agreed with Dr. Lee that the goals of treating patients with chronic GVHD include improving symptoms and quality, preventing progression, ideally tapering patients off immunosuppression, and achieving a balance between preventing negative consequences of GVHD while maintain the benefits of a graft-versus-leukemia effect.

“In our center, drug choice is based on physician preference and comfort with how often they’ve used the drug, patients’ comorbidities, toxicities of the drug, and logistical considerations,” Dr. Hamilton said.

Dr. Lee disclosed consulting activities for Pfizer and Kadmon, travel and lodging from Amgen, and research funding from those companies and others. Dr. Hamilton disclosed consulting for Syndax and Incyte.

Despite improvements in prevention of graft-versus-host disease, chronic GVHD still occurs in 10%-50% of patients who undergo an allogeneic hematopoietic stem cell transplant, and these patients may require prolonged treatment with multiple lines of therapy, said a hematologist and transplant researcher.

“More effective, less toxic therapies for chronic GVHD are needed,” Stephanie Lee, MD, MPH, from the Fred Hutchinson Cancer Research Center in Seattle said at the Transplant & Cellular Therapies Meetings.

Dr. Lee reviewed clinical trials for chronic GVHD at the meeting held by the American Society for Blood and Marrow Transplantation and the Center for International Blood and Marrow Transplant Research.

Although the incidence of chronic GVHD has gradually declined over the last 40 years and both relapse-free and overall survival following a chronic GVHD diagnosis have improved, “for patients who are diagnosed with chronic GVHD, they still will see many lines of therapy and many years of therapy,” she said.

Among 148 patients with chronic GVHD treated at her center, for example, 66% went on to two lines of therapy, 50% went on to three lines, 37% required four lines of therapy, and 20% needed five lines or more.

Salvage therapies for patients with chronic GVHD have evolved away from immunomodulators and immunosuppressants in the early 1990s, toward monoclonal antibodies such as rituximab in the early 2000s, to interleukin-2 and to tyrosine kinase inhibitors such as ruxolitinib (Jakafi) and ibrutinib (Imbruvica).

There are currently 36 agents that are FDA approved for at least one indication and can also be prescribed for the treatment of chronic GVHD, Dr. Lee noted.
 

Treatment goals

Dr. Lee laid out six goals for treating patients with chronic GVHD. They include:

• Controlling current signs and symptoms, measured by response rates and patient-reported outcomes
• Preventing further tissue and organ damage
• Minimizing toxicity
• Maintaining graft-versus-tumor effect
• Achieving graft tolerance and stopping immunosuppression
• Decreasing nonrelapse mortality and improving survival

Active trials

Dr. Lee identified 33 trials with chronic GVHD as an indication that are currently recruiting, and an additional 13 trials that are active but closed to recruiting. The trials can be generally grouped by mechanism of action, and involve agents targeting T-regulatory cells, B cells and/or B-cell receptor (BCR) signaling, monocytes/macrophages, costimulatory blockage, a proteasome inhibition, Janus kinase (JAK) 1/2 inhibitors, ROCK2 inhibitors, hedgehog pathway inhibition, cellular therapy, and organ-targeted therapy.

Most of the trials have overall response rate as the primary endpoint, and all but five are currently in phase 1 or 2. The currently active phase 3 trials include two with ibrutinib, one with the investigational agent itacitinib, one with ruxolitinib, and one with mesenchymal stem cells.

“I’ll note that, when results are reported, the denominator really matters for the overall response rate, especially if you’re talking about small trials, because if you require the patient to be treated with an agent for a certain period of time, and you take out all the people who didn’t make it to that time point, then your overall response rate looks better,” she said.
 

BTK inhibitors

The first-in-class Bruton tyrosine kinase (BTK) inhibitor ibrutinib was the first and thus far only agent approved by the Food and Drug Administration for chronic GVHD. The approval was based on a single-arm, multicenter trial with 42 patients.

The ORR in this trial was 69%, consisting of 31% complete responses and 38% partial responses, with a duration of response longer than 10 months in slightly more than half of all patients. In all, 24% of patients had improvement of symptoms in two consecutive visits, and 29% continued on ibrutinib at the time of the primary analysis in 2017.

Based on these promising results, acalabrutinib, which is more potent and selective for BTK than ibrutinib, with no effect on either platelets or natural killer cells, is currently under investigation in a phase 2 trial in 50 patients at a dose of 100 mg orally twice daily.
 

JAK1/2 inhibition

The JAK1 inhibitor itacitinib failed to meet its primary ORR endpoint in the phase 3 GRAVITAS-301 study, according to a press release, but the manufacturer (Incyte) said that it is continuing its commitment to JAK inhibitors with ruxolitinib, which has shown activity against acute, steroid-refractory GVHD, and is being explored for prevention of chronic GVHD in the randomized, phase 3 REACH3 study.

The trial met its primary endpoint for a higher ORR at week 24 with ruxolitinib versus best available therapy, at 49.7% versus 25.6%, respectively, which translated into an odds ratio for response with the JAK inhibitor of 2.99 (P < .0001).
 

Selective T-cell expansion

Efavaleukin alfa is an IL-2-mutated protein (mutein), with a mutation in the IL-2RB-binding portion of IL-2 causing increased selectivity for regulatory T-cell expansion. It is bound to an IgG-Fc domain that is itself mutated, with reduced Fc receptor binding and IgG effector function to give it a longer half life. This agent is being studied in a phase 1/2 trial in a subcutaneous formulation delivered every 1 or 2 weeks to 68 patients.

Monocyte/macrophage depletion

Axatilimab is a high-affinity antibody targeting colony stimulating factor–1 receptor (CSF-1R) expressed on monocytes and macrophages. By blocking CSF-1R, it depletes circulation of nonclassical monocytes and prevents the differentiation and survival of M2 macrophages in tissue.

It is currently being investigated 30 patients in a phase 1/2 study in an intravenous formulation delivered over 30 minutes every 2-4 weeks.
 

Hedgehog pathway inhibition

There is evidence suggesting that hedgehog pathway inhibition can lessen fibrosis. Glasdegib (Daurismo) a potent selective oral inhibitor of the hedgehog signaling pathway, is approved for use with low-dose cytarabine for patients with newly diagnosed acute myeloid leukemia aged older than 75 years or have comorbidities precluding intensive chemotherapy.

This agent is associated with drug intolerance because of muscle spasms, dysgeusia, and alopecia, however.

The drug is currently in phase 1/2 at a dose of 50 mg orally per day in 20 patients.
 

ROCK2 inhibition

Belumosudil (formerly KD025) “appears to rebalance the immune system,” Dr. Lee said. Investigators think that the drug dampens an autoaggressive inflammatory response by selective inhibition of ROCK2.

This drug has been studied in a dose-escalation study and a phase 2 trial, in which 132 participants were randomized to receive belumosudil 200 mg either once or twice daily.

At a median follow-up of 8 months, the ORR with belumosudil 200 mg once and twice daily was 73% and 74%, respectively. Similar results were seen in patients who had previously received either ruxolitinib or ibrutinib. High response rates were seen in patients with severe chronic GVHD, involvement of four or more organs and a refractory response to their last line of therapy.
 

Hard-to-manage patients

“We’re very hopeful for many of these agents, but we have to acknowledge that there are still many management dilemmas, patients that we just don’t really know what to do with,” Dr. Lee said. “These include patients who have bad sclerosis and fasciitis, nonhealing skin ulcers, bronchiolitis obliterans, serositis that can be very difficult to manage, severe keratoconjunctivitis that can be eyesight threatening, nonhealing mouth ulcers, esophageal structures, and always patients who have frequent infections.

“We are hopeful that some these agents will be useful for our patients who have severe manifestations, but often the number of patients with these manifestations in the trials is too low to say something specific about them,” she added.
 

‘Exciting time’

“It’s an exciting time because there are a lot of different drugs that are being studied for chronic GVHD,” commented Betty Hamilton, MD, a hematologist/oncologist at the Cleveland Clinic.

“I think that where the field is going in terms of treatment is recognizing that chronic GVHD is a pretty heterogeneous disease, and we have to learn even more about the underlying biologic pathways to be able to determine which class of drugs to use and when,” she said in an interview.

She agreed with Dr. Lee that the goals of treating patients with chronic GVHD include improving symptoms and quality, preventing progression, ideally tapering patients off immunosuppression, and achieving a balance between preventing negative consequences of GVHD while maintain the benefits of a graft-versus-leukemia effect.

“In our center, drug choice is based on physician preference and comfort with how often they’ve used the drug, patients’ comorbidities, toxicities of the drug, and logistical considerations,” Dr. Hamilton said.

Dr. Lee disclosed consulting activities for Pfizer and Kadmon, travel and lodging from Amgen, and research funding from those companies and others. Dr. Hamilton disclosed consulting for Syndax and Incyte.