Belantamab mafodotin has shown clinical activity and a manageable safety profile in a real-world population of patients with relapsed/refractory multiple myeloma, according to research published in Haematologica.
The anti-BCMA antibody-drug conjugate demonstrated survival and response rates similar to those seen in the DREAMM-2 trial, researchers reported. Toxicity was also similar, with adverse events most commonly being ophthalmological in nature.
The current study included 106 patients treated between November 2019 and December 2020. Ninety-seven patients were evaluable for efficacy, and 104 were evaluable for safety.
In the efficacy population, the median age at diagnosis was 66 years (range, 37-82), and 50.5% of patients were men. The median time from diagnosis was 6.37 years. The patients had received a median of 5 prior lines of therapy (range, 3-12). All patients had received at least 1 immunomodulatory drug, proteasome inhibitor, and anti-CD38 monoclonal antibody.
Patients received a median of 3 cycles of belantamab mafodotin (range, 1-22). The best overall response rate (ORR) was 38.1%. This included complete responses in 8.2% of patients, very good partial responses in 11.3%, and partial responses in 18.6%.
The 38.1% ORR is the highest ORR reported thus far for belantamab mafodotin, according to the researchers. The ORR in the DREAMM-2 trial was 31% in patients who received belantamab mafodotin at 2.5 mg/kg, the recommended dose.
In the current study, the median time to achieve the best response was 2.05 months, and the median duration of response was 9 months. The median time to next treatment was 4.25 months.
The median overall survival (OS) was 9.3 months, and the median progression-free survival (PFS) was 3.5 months. According to the researchers, these results were in line with previous studies of belantamab mafodotin. In DREAMM-2, the median OS was 13.8 months, and the median PFS was 2.8 months in patients who received the recommended dose.
The toxicity profile of belantamab mafodotin in the current study was similar to that in previous studies, the researchers reported. In the current study, ophthalmic toxicity was the most common adverse event. It occurred in 48% of evaluable patients; 40.8% of cases were grade 3, and there were no grade 4 cases.
Grade 3-4 hematologic toxicity occurred in 15.4% of patients, with thrombocytopenia (43.8%) being the most common event. Treatment-related toxicity resulted in treatment discontinuation in 36.5% of patients.
“Overall, the results of our retrospective real-life study are concordant with the previously reported results of the phase 2 clinical trial DREAMM-2 in terms of response, survival, and toxicities,” the researchers concluded. “Although the ophthalmological issues are a concern, BM [belantamab mafodotin] remains an alternative option for previously highly treated patients that can thus benefit from an anti-BCMA therapy in the late course of disease.”
Belantamab mafodotin was pulled from the US market in November 2022 because results from the DREAMM-3 trial did not meet requirements to support continued approval. However, belantamab mafodotin is still available to US patients via a compassionate use program.
GSK, the company developing belantamab mafodotin, said it will continue the DREAMM clinical trial program and work with the US Food and Drug Administration “on a path forward” for belantamab mafodotin.
Disclosures: This research was supported by GSK. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
1. Talbot A, Bobin A, Tabone L, et al. Real-world study of the efficacy and safety of belantamab mafodotin (GSK2857916) in relapsed or refractory multiple myeloma based on data from the nominative ATU in France: IFM 2020-04 study. Haematologica. Published online April 20, 2023. doi:10.3324/haematol.2022.281772
2. Lonial S, Lee HC, Badros A, et al. Belantamab mafodotin for relapsed or refractory multiple myeloma (DREAMM-2): A two-arm, randomised, open-label, phase 2 study. Lancet Oncol. 2020;21(2):207-221. doi:10.1016/S1470-2045(19)30788-0
3. GSK provides an update on Blenrep (belantamab mafodotin-blmf) US marketing authorisation. News release. GSK. Published November 22, 2022. Accessed May 5, 2023.
This article originally appeared on Cancer Therapy Advisor