GSK announces further positive data from DREAMM-1 study of anti-BCMA antibody-drug conjugate in patients with relapsed/refractory multiple myeloma

GlaxoSmithKline plc announced further positive data from the DREAMM-1 study of patients with relapsed/refractory multiple myeloma who received GSK2857916, an investigational anti-B-cell maturation antigen (BCMA) antibody-drug conjugate. These results, published in Blood Cancer Journal build upon results from the pre-specified interim analysis, which were first presented at the American Society of Haematology Congress in 2017.

These new data confirm that 60% of patients receiving GSK2857916 achieved an overall response rate (ORR). This ORR was identical to the rate previously reported in the interim analysis, after more than a year of follow-up, and demonstrates not only the potential efficacy of the medicine but the durability and depth of response. The number of patients achieving a complete response increased to 15% over this additional one year follow-up period. The median progression-free survival (PFS) was 12 months (95% CI [3.1-Not Estimable/NE]), an increase from the previously reported 7.9 months PFS. The median duration of response in the final analysis was 14.3 months (95% CI [10.6-NE]). All patients whose data were reported in the interim analysis were included in this analysis.

Dr Hal Barron, Chief Scientific Officer and President, R&D, GSK, commented, “These data are very encouraging and I am excited by what they could mean for people living with multiple myeloma. We are aggressively advancing this potential new medicine and plan to have pivotal data to support its filing by the end of this year.”

A total of 35 patients were enrolled in Part 2 of the DREAMM-1 study independent of their BCMA expression levels. Amongst those heavily pre-treated patients not previously treated with the anti-CD38 monoclonal antibody, daratumumab, the ORR was 71% (95% CI [47.8%,88.7%]) with a mPFS of 15.7 months, (95% CI [2.3-NE]). In those patients who had previously been treated with daratumumab, the ORR was 38.5%; (95% CI [13.9-68.4]) with a mPFS of 7.9 months (95% CI [2.3-NE]).

No new safety signals were identified during this treatment period. The most commonly reported adverse events were thrombocytopenia (63%), blurred vision (51%), cough (40%), which were mostly mild or moderate (Grade 1 or 2). The most commonly reported Grade 3 or 4 adverse events were thrombocytopenia (35%) and anemia (17%) and were found to be manageable.

Paul Giusti, President and Chief Executive Officer of the Multiple Myeloma Research Foundation (MMRF), said, “Significant advancements have been made in our knowledge, understanding and the treatment of multiple myeloma in the past decade, but there is so much more that we as a community need to do to accelerate better outcomes and quality of life for patients. Relapses are particularly challenging, so the need for treatment advances is a priority at the MMRF to ensure our patients can benefit from them in the future. We are encouraged by the results from this early study, and we look forward to seeing additional data later this year.”

Multiple myeloma is the second most common blood cancer in the United States[i] and is generally considered treatable but not curable. Multiple myeloma commonly becomes refractory to available treatments, so research into new treatments is vital.

In 2017, GSK2857916 was awarded Breakthrough Therapy designation from the U.S. Food and Drug Administration and PRIME designation from the European Medicines Agency; these designations are intended to facilitate development of investigational medicines that have shown clinical promise for conditions where there is significant unmet need.