Patients who took isatuximab (Sarclisa) plus bortezomib, lenalidomide, and dexamethasone (VRd) reached higher estimated progression-free survival at a median 59.7 months vs. those who took VRd alone (63.2% vs. 45.2%, respectively, 98.5% CI, hazard ratio [HR] = 0.60, P < .001), reported Thierry Facon, MD, professor of hematology at Lille University Hospital, France, and colleagues at the annual meeting of the American Society of Clinical Oncology in Chicago. The study was simultaneously published in The New England Journal of Medicine.
“The significant progression-free benefit observed with Sarclisa with combination therapy compared to VRd is important and encouraging for patients with newly diagnosed multiple myeloma,” Dr. Facon said in an interview. The findings demonstrated the VRd-isatuximab’s potential as “a first-in-class combination to address gaps in care for newly diagnosed multiple myeloma transplant-ineligible patients,” he said.
According to Dr. Facon, more than 180,000 people worldwide are diagnosed with MM each year, he said, making it the second-most common hematologic malignancy.
“There is a need for new frontline therapeutic options for all MM patients,” he said. “Effective frontline therapy has the potential to modify the course of the disease, which is a key outcome for transplant-ineligible patients who often face high rates of attrition in later lines of therapy.”
For the industry-funded IMROZ study, researchers recruited patients aged 18-80 at 93 sites in 21 nations from 2017-2019. All were ineligible for transplant due to comorbidities or being aged 65 or older. Exclusions included Eastern Cooperative Oncology Group (ECOG) performance status scores of more than 2.
The subjects were randomly assigned in a 3-to-2 ratio to isatuximab-VRd (n = 265) or VRd alone (n = 181) and received four induction cycles (6 weeks per cycle) followed by 4-week cycles of continuous treatment until disease progression, unacceptable adverse event, or other criteria for discontinuation. If progression occurred, patients could be switched from the VRd-only group to the isatuximab-VRd group.
The median age in both the isatuximab-VRd and VRd groups was 72. The percentages of women were 46.0% and 48.1%, respectively, and 72.5% and 72.4%, respectively, were White. The next largest race/ethnic group was Asian (11.7% and 9.4%, respectively). Almost all had ECOG status of 0 or 1 (88.7% and 89.5%, respectively).
At study cut-off in September 2023, the percentages of subjects in the isatuximab-VRd and VRd groups who were still receiving treatment were 47.2% and 24.3%, respectively.
An intention-to-treat analysis found that the two groups had similar rates of overall response (91.3% for isatuximab-VRd vs. 92.3% for VRd), but the isatuximab-VRd group had higher complete or better response (74.7% vs. 64.1%, P = .01).
The percentage of patients who were minimal residual disease (MRD)-negative and had a complete response was also higher in the VRd-isatuximab group vs. the VRd group (55.5% vs. 40.9%, respectively, P = .003). A total of 26.0% of patients in the VRd-isatuximab group died vs. 32.6% in the VRd group; the estimated overall survival rates at 60 months were 72.3% and 66.3%, respectively, HR = 0.78, 99.97% CI).
As for adverse events, grade 5 events were more common in the VRd-isatuximab group (11.0% vs. 5.5%), as were deaths within the first 60 days of treatment (1.5% vs. 0.6%). “The difference was driven in part by different treatment exposures,” the researchers reported. Treatment-emergent events led to treatment discontinuation in 22.8% and 26.0% of patients, respectively.
“The safety and tolerability of Sarclisa observed was consistent with the established safety profile of Sarclisa and VRd with no new safety signals observed,” Dr. Facon said.
In an interview, Zandra Klippel, MD, global product head for multiple myeloma at Sanofi — the maker of isatuximab and funder of the study — said the Food and Drug Administration has accepted a priority review application for the investigational use of isatuximab in combination with VRd for the treatment of patients with transplant-ineligible, newly diagnosed MM.
“Our FDA approval date is expected on September 27, 2024,” Dr. Klippel said. “If all goes well, we anticipate launching as early as 2024 in the US and rolling out in other key countries starting in 2025 and continuing through 2026.”
Dr. Klippel added that isatuximab “continues to be evaluated in multiple ongoing phase 3 clinical trials in combination with current standard treatments across the MM treatment continuum.”
In an interview, Sagar Lonial, MD, chair and professor of hematology and medical oncology and chief medical officer at Winship Cancer Institute at Emory University in Atlanta, said the study is “important.”
However, Dr. Lonial, who is familiar with the findings but didn’t take part in the study, said it’s difficult to understand the impact of the treatment on frail patients. It appears that the combination treatment may be good for frail patients, he said, “but I need to better understand the magnitude of the benefit in that subset a little more.”
As for adverse events, he said “they are what would be expected for a trial like this.”
Pneumonia and COVID-19 infections were higher in the VRd-isatuximab group, he said, and “we know in general that vaccine responses are blocked by CD38 antibodies.” This can be managed, he said, via intravenous immunoglobulin support.
Manni Mohyuddin, MD, assistant professor at Huntsman Cancer Institute in Utah, said in an interview that the findings suggest that in older, fit patients, “you can get fairly good outcomes without use of transplant.”
In the United States, many more patients in the cohort would have been considered transplant-eligible, he said, and not eliminated from consideration for transplant due to age over 65. However, as patients age, “you get more diminishing returns for transplants,” said Dr. Mohyuddin, who is familiar with the study findings but didn’t take part in the research.
All the drugs in the new combination are FDA approved, he said, although the combination isn’t. “I suspect this will make it to our guidelines very soon and then be reimbursed by insurance companies and Medicare.”
The study was funded by Sanofi and an M.D. Anderson Cancer Center support grant. Dr. Facon has no disclosures. Other study authors report multiple ties relationships with various drug makers. Dr. Lonial disclosed ties with Takeda, Amgen, Novartis, BMS, GSK, AbbVie, Genentech, Pfizer, Regeneron, Janssen, AstraZeneca, and TG Therapeutics). Dr. Mohyuddin disclosed a relationship with Janssen.