On 6 February 2024, GlaxoSmithKline (GSK) announced results from an interim analysis of the DREAMM-7 phase III trial presented at an American Society of Clinical Oncology (ASCO) online plenary session. The trial is evaluating belantamab mafodotin (“belamaf” or trade name Blenrep®) combined with bortezomib plus dexamethasone (BorDex) versus daratumumab plus BorDex in second line and later treatment of relapsed or refractory myeloma.

Key results from the presentation include:

• A main research question in the trial (also known as a “primary endpoint”) was how progression free survival (PFS – the length of time before the disease progresses) compared between the two trial arms.
• The belamaf combination (number of patients = 243) showed a 59% reduction in the risk of disease progression or death compared to the daratumumab combination (number of patients = 251).
• With a median follow-up of 28.2 months, the median PFS was 36.6 months with the belamaf combination compared to 13.4 months in the daratumumab combination.
• An overall survival (OS) trend was observed at the interim analysis, with a 43% reduction in the risk of death, although the statistical significance of this has not yet been confirmed. OS follow-up continues and further analyses are planned.
• Documented side effects for belamaf are eye related. The study found that 34% of patients had grade 3 or higher events (severe side-effects), including blurred vision (22%), dry eye (7%), eye irritation (5%), and visual impairment (5%). The company reported that these were generally reversable and manageable with dose modifications.

GSK also reported that the PFS effect was observed across all prespecified subgroups, including those who were refractory to lenalidomide and those with high-risk cytogenetics.

The interim data from the DREAMM-7 trial shows potential promise for future European approval and reimbursement for belamaf after the European Medicines Agency (the EU medicines regulator) Committee for Medicinal Products for Human Use (CHMP) confirmed their earlier recommendation to not renew marketing authorisation for belamaf mafadotin in December 2023, specifically as a monotherapy for heavily pre-treated patients.

The decision means that the current EU marketing authorisation for belamaf will be removed after ratification by the European Commission and that reimbursement of belamaf in some EU countries is also likely to end. However, the manufacturer, GSK, confirmed that they will continue to provide the medicine to patients who are already receiving it. 

For further information about belamaf, including mechanism of action and side-effects, read the MPE belantamab mafadotin factsheet.