In the real-world setting, belantamab mafodotin demonstrates comparable responses and toxicities in patients with multiple myeloma (MM) to those seen in clinical trials, according to a study presented at the 2021 ASH Annual Meeting.

In a recent phase 2 study (Lonial et al, Lancet Oncology 2020), single-agent belantamab mafodotin showed antimyeloma activity with manageable safety in patients with relapsed/refractory MM.

“Patients enrolled on clinical trials, however, often do not reflect a real-world population due to eligibility criteria that limit comorbidities and include wash-out periods not typical of clinical practice,” wrote Malin Hultcrantz, MD, PhD, Myeloma Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, and colleagues.

This study aimed to assess response rates, dose modifications, and frequency of ocular adverse events among patients treated with belantamab mafodotin in the real-world setting.

A total of 42 patients treated with commercial belantamab mafodotin at Memorial Sloan Kettering Cancer Center between October 2020 and July 2021 were included in the study. Of these patients, 23 (55%) were women and the median age was 67 years.

There were 12 patients that had been included in the Expanded Access Program with belantamab mafodotin prior to transitioning to commercial belantamab mafodotin. High-risk cytogenetics were reported for 30 (71%) patients and included gain 1q, t(4;14), t(14;16), t(14;20), complex karyotype, and MYC-translocations.

Patients received a median of 7 prior lines of therapy. All patients had received an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 antibody. In addition, 11 patients had received a BCMA-targeted agent in clinical trials, including bi-specific antibodies and CAR T-cells. There was 1 patient who received prior therapy with belantamab mafodotin in a clinical trial.

Patients received a median of 3 cycles of belantamab mafodotin as a single agent (n = 40, 95%) or in combination with other standard myeloma treatments (n = 2).

Among all patients, the overall response rate (ORR) was 43% (n = 18); 7 patients achieved a partial response; 5 patients achieved a very good partial response, 4 patients achieved a complete response (CR) and 1 patient achieved a stringent CR.

Of the 18 patients in the ORR cohort, the median duration of response was 11 months. There were 3 patients who achieved a minimal response, 6 patients had stable disease, and 1 patient was not evaluable for response assessment.

After a median follow-up of 7.5 months, 14 patients had progressive disease and 10 patients had died. At the time of data cutoff, 16 patients continued treatment with belantamab mafodotin.

Any grade ocular toxicity on ophthalmology exam was reported in 27 (64%) patients. Using the Keratopathy and Visual Acuity scale, 12 patients had grade 1 keratopathy, 7 had grade 2, and 8 had grade 3. Corneal microcysts were present in 14 patients. In addition, 18 patients experienced a decline in best corrected visual acuity: 10 patients with grade 1, 5 with grade 2, and 3 with grade 3 decline.

Dose reductions were reported in 17 patients, 16 due to ocular toxicity and 1 due to baseline cytopenia. In addition, ≥1 dose were delayed in 9 patients due to keratopathy, thought 8 patients were able to continue therapy with maintained response on a lower dose.

“These data demonstrate encouraging results for belantamab mafodotin treatment in the real-world setting with responses and toxicities comparable to clinical trial subjects,” concluded Dr Hultcrantz and colleagues.

Hultcrantz M, Orozco J, Peterson TJ,  et al. Belantamab Mafodotin in Patients with Relapsed/Refractory Multiple Myeloma, a Real-World Experience. Presented at the: 2021 Ash Annual Meeting; December 11-14, 2021; Atlanta, GA and virtual. Abstract 1644.