Isavuconazole resolved invasive fungal disease in patients on ibrutinib

Treatment with isavuconazole resolved or substantially improved invasive fungal disease among seven of eight patients receiving concomitant ibrutinib, according to the results of a small two-center study.

The combination “was well-tolerated overall,” wrote Kaelyn C. Cummins of Brigham and Women’s Hospital, together with her associates there and at the Dana-Farber Cancer Institute, Boston. Their letter to the editor was published in Leukemia & Lymphoma.

Although ibrutinib is considered less immunosuppressive than conventional chemotherapy, it has been tied to invasive fungal infections, even in seemingly low-risk patients. The preferred treatment, voriconazole, is a very strong inhibitor of cytochrome P450 systems, of which ibrutinib is a substrate. For this study, the researchers queried the pharmacy databases of their institutions to identify adults who received concomitant isavuconazole (200 mg per day) and ibrutinib between 2015 and 2018. Drug exposures were confirmed by medical record review.

Four patients experienced clinical and radiologic resolution of invasive aspergillosis, fusariosis, mucormycosis, or phaeohyphomycosis. Another three had clinical and radiologic improvement of confirmed or probable aspergillosis or histoplasmosis. One of these patients underwent five debridements for central nervous system invasive aspergillosis but had 8 months of clinical improvement between debridements. This patient’s fungal isolate remained susceptible to isavuconazole throughout treatment. The patient who did not respond at all to isavuconazole had invasive aspergillosis with recurrent brain abscesses. The fungal isolate remained susceptible to isavuconazole, and the patient switched to long-term voriconazole therapy after stopping ibrutinib.

Several adverse events occurred while patients were on concomitant therapy. One patient developed paroxysmal atrial fibrillation that persisted after stopping ibrutinib. Another had worsening of preexisting thrombocytopenia. Among four patients with electrocardiogram data, two had transient QTc prolongation. No patient died within 12 weeks of starting concomitant therapy. Two patients eventually died after their cancer progressed.

The median age of the patients was 60 years (range, 38-76 years). Five were men. Six had chronic lymphocytic leukemia (CLL) and two had marginal zone lymphoma. Two CLL patients were on ibrutinib monotherapy, two also received rituximab, one also received umbralisib, and one also received obinutuzumab. One patient with marginal zone lymphoma was on ibrutinib monotherapy, and the other received concomitant rituximab, gemcitabine, dexamethasone, and cisplatin.

Researchers should study the mechanisms by which [Bruton’s tyrosine kinase] inhibitors might increase susceptibility to fungal infections among patients with lymphoma or CLL, said Ms. Cummins and her associates. Because the CYP3A enzyme system also metabolizes PI3K and BCL-2 inhibitors, their results “could be more broadly applicable.”

Ms. Cummins had no disclosures.

SOURCE: Cummins KC et al. Leuk. Lymphoma 2018 Jul 24. doi: 10.1080/10428194.2018.1485913.

Treatment with isavuconazole resolved or substantially improved invasive fungal disease among seven of eight patients receiving concomitant ibrutinib, according to the results of a small two-center study.

The combination “was well-tolerated overall,” wrote Kaelyn C. Cummins of Brigham and Women’s Hospital, together with her associates there and at the Dana-Farber Cancer Institute, Boston. Their letter to the editor was published in Leukemia & Lymphoma.

Although ibrutinib is considered less immunosuppressive than conventional chemotherapy, it has been tied to invasive fungal infections, even in seemingly low-risk patients. The preferred treatment, voriconazole, is a very strong inhibitor of cytochrome P450 systems, of which ibrutinib is a substrate. For this study, the researchers queried the pharmacy databases of their institutions to identify adults who received concomitant isavuconazole (200 mg per day) and ibrutinib between 2015 and 2018. Drug exposures were confirmed by medical record review.

Four patients experienced clinical and radiologic resolution of invasive aspergillosis, fusariosis, mucormycosis, or phaeohyphomycosis. Another three had clinical and radiologic improvement of confirmed or probable aspergillosis or histoplasmosis. One of these patients underwent five debridements for central nervous system invasive aspergillosis but had 8 months of clinical improvement between debridements. This patient’s fungal isolate remained susceptible to isavuconazole throughout treatment. The patient who did not respond at all to isavuconazole had invasive aspergillosis with recurrent brain abscesses. The fungal isolate remained susceptible to isavuconazole, and the patient switched to long-term voriconazole therapy after stopping ibrutinib.

Several adverse events occurred while patients were on concomitant therapy. One patient developed paroxysmal atrial fibrillation that persisted after stopping ibrutinib. Another had worsening of preexisting thrombocytopenia. Among four patients with electrocardiogram data, two had transient QTc prolongation. No patient died within 12 weeks of starting concomitant therapy. Two patients eventually died after their cancer progressed.

The median age of the patients was 60 years (range, 38-76 years). Five were men. Six had chronic lymphocytic leukemia (CLL) and two had marginal zone lymphoma. Two CLL patients were on ibrutinib monotherapy, two also received rituximab, one also received umbralisib, and one also received obinutuzumab. One patient with marginal zone lymphoma was on ibrutinib monotherapy, and the other received concomitant rituximab, gemcitabine, dexamethasone, and cisplatin.

Researchers should study the mechanisms by which [Bruton’s tyrosine kinase] inhibitors might increase susceptibility to fungal infections among patients with lymphoma or CLL, said Ms. Cummins and her associates. Because the CYP3A enzyme system also metabolizes PI3K and BCL-2 inhibitors, their results “could be more broadly applicable.”

Ms. Cummins had no disclosures.

SOURCE: Cummins KC et al. Leuk. Lymphoma 2018 Jul 24. doi: 10.1080/10428194.2018.1485913.

Treatment with isavuconazole resolved or substantially improved invasive fungal disease among seven of eight patients receiving concomitant ibrutinib, according to the results of a small two-center study.

The combination “was well-tolerated overall,” wrote Kaelyn C. Cummins of Brigham and Women’s Hospital, together with her associates there and at the Dana-Farber Cancer Institute, Boston. Their letter to the editor was published in Leukemia & Lymphoma.

Although ibrutinib is considered less immunosuppressive than conventional chemotherapy, it has been tied to invasive fungal infections, even in seemingly low-risk patients. The preferred treatment, voriconazole, is a very strong inhibitor of cytochrome P450 systems, of which ibrutinib is a substrate. For this study, the researchers queried the pharmacy databases of their institutions to identify adults who received concomitant isavuconazole (200 mg per day) and ibrutinib between 2015 and 2018. Drug exposures were confirmed by medical record review.

Four patients experienced clinical and radiologic resolution of invasive aspergillosis, fusariosis, mucormycosis, or phaeohyphomycosis. Another three had clinical and radiologic improvement of confirmed or probable aspergillosis or histoplasmosis. One of these patients underwent five debridements for central nervous system invasive aspergillosis but had 8 months of clinical improvement between debridements. This patient’s fungal isolate remained susceptible to isavuconazole throughout treatment. The patient who did not respond at all to isavuconazole had invasive aspergillosis with recurrent brain abscesses. The fungal isolate remained susceptible to isavuconazole, and the patient switched to long-term voriconazole therapy after stopping ibrutinib.

Several adverse events occurred while patients were on concomitant therapy. One patient developed paroxysmal atrial fibrillation that persisted after stopping ibrutinib. Another had worsening of preexisting thrombocytopenia. Among four patients with electrocardiogram data, two had transient QTc prolongation. No patient died within 12 weeks of starting concomitant therapy. Two patients eventually died after their cancer progressed.

The median age of the patients was 60 years (range, 38-76 years). Five were men. Six had chronic lymphocytic leukemia (CLL) and two had marginal zone lymphoma. Two CLL patients were on ibrutinib monotherapy, two also received rituximab, one also received umbralisib, and one also received obinutuzumab. One patient with marginal zone lymphoma was on ibrutinib monotherapy, and the other received concomitant rituximab, gemcitabine, dexamethasone, and cisplatin.

Researchers should study the mechanisms by which [Bruton’s tyrosine kinase] inhibitors might increase susceptibility to fungal infections among patients with lymphoma or CLL, said Ms. Cummins and her associates. Because the CYP3A enzyme system also metabolizes PI3K and BCL-2 inhibitors, their results “could be more broadly applicable.”

Ms. Cummins had no disclosures.

SOURCE: Cummins KC et al. Leuk. Lymphoma 2018 Jul 24. doi: 10.1080/10428194.2018.1485913.