USA — British pharma giant GSK is set to withdraw its blood cancer drug Blenrep from the U.S. market, following a request from the Food and Drug Administration.
Blenrep belongs to a category of treatments called antibody-drug conjugates, which are engineered antibodies that bind to tumor cells and then release cell-killing chemicals.
The company was obliged to carry out this confirmatory trial after the FDA granted accelerated approval for the drug in August 2020 for patients with relapsed or refractory multiple myeloma who received at least four previous therapies.
The accelerated approval was based on response data, and it was dependent on later trials’ confirming a clinical benefit. In this case, those trials didn’t.
It failed to improve progression-free survival (PFS) or overall survival (OS) compared to standard therapy with pomalidomide/dexamethasone in patients who had previously been treated with at least two rounds of lenalidomide and a proteasome inhibitor therapy.
The company had said this month that Blenrep had failed the main goal of a key study designed to show it was better than an existing treatment on the market, stoking fears that regulatory approval could be rescinded by the U.S. Food and Drug Administration (FDA).
GSK said it has begun the process to withdraw Blenrep’s marketing authorization in the country but would continue trial programs for the drug, adding that some patients would have the option to enroll for continued access to the treatment.
Further clinical trials in the DREAMM program are still underway. Results from the DREAMM-7 and DREAMM-8 trials are expected in early 2023.
“We will continue the DREAMM clinical trial program and work with the U.S. FDA on a path forward for this important treatment option for patients with multiple myeloma,” GSK Chief Medical Officer Sabine Luik said in a statement.
Marketing of Blenrep continues in 17 other countries, mostly in the European Union where it has been approved, a GSK official said, but the U.S. move will raise doubts about the drug’s future.
The company is still discussing the latest clinical data with EU health authorities, the official said.
The company had high hopes for the drug when it was launched. At that time, blenrep was the only drug on the market that targeted B-Cell Maturation Antigen (BCMA), and so it was the first drug in its class.
However, it is no longer unique. In the 2 years that it has been available, several other products that target BCMA have been launched for use in the treatment of multiple myeloma.
These include the two chimeric antigen receptor T-cell products, Abecma (Bristol-Myers Squibb) and Carvykti, as well as the bispecific antibody teclistamab (Tecvayli) both from Johnson & Johnson.