GSK moves further ahead in BCMA with EU okay for Blenrep

GlaxoSmithKline has approval on both sides of the Atlantic for its multiple myeloma drug Blenrep, after getting the nod from the European Commission.

Blenrep (belantamab mafodotin) becomes the first BCMA-targeted drug for myeloma to be approved in the EU, and according to its label can be used to treat the blood cancer in adult patients who have received at least four prior therapies.

Prior drugs have to include an immunomodulatory agent, a proteasome inhibitor and a CD-38 monoclonal antibody, and the patient must show progression of the disease since the last therapy.

Among a crowded field, GSK has now won the race to bring an anti-BCMA drug to market in both Europe and the US. The FDA backed Blenrep for the same indication three weeks ago, despite some reservations about eye toxicity, which set the drug on course for what some analysts think could be revenues of around $1.5 billion in 2026.

The EU and US approvals for Blenrep are based on two phase 2 trials – DREAMM-1 and DREAMM-2 – which showed that the antibody-drug conjugate (ADC) achieved responses in around a third of patients who had received an average of seven prior treatments for the cancer.

The conditional approvals mean that GSK may need survival data from a larger trial to keep the drug on the market in the longer term.

That data should come from an ongoing phase 3 study comparing Blenrep with BMS’ immunomodulatory drug Pomalyst (pomalidomide) plus low-dose dexamethasone, the standard treatment option for relapsed and refractory multiple myeloma.

It’s a key new launch for GSK as it tries to rebuild its oncology business under chief scientific officer Hal Barron, along with PD-1 inhibitor dostarlimab and PARP inhibitor Zejula (niraparib) – acquired as part of its $5.1 billion takeover of Tesaro.

Blenrep looks set to have a longer-than-expected period without direct BCMA competition after a BCMA-targeted cell therapy from Bristol-Myers Squibb and bluebird bio – ide-cel (bb2121) – was held up by an FDA request for more data.

Ide-cel was resubmitted to the FDA earlier this month, while other BCMA drugs coming through the pipeline include Amgen’s AMG-429 and Regeneron’s REGN5458 – both bispecific antibodies – as well as ADCs from AstraZeneca and BMS.

With approvals in hand for later-line therapy of myeloma, GSK’s attention will now switch to developing the drug for earlier use in the disease.

Its head-to-head trial with Pomalyst is recruiting patients with at least two prior lines of anti-myeloma treatments, and it also has a phase 3 trial running adding Blenrep to standard first-line treatment with Takeda’s proteasome inhibitor Velcade (bortezomib), BMS’ immunomodulator Revlimid (lenalidomide) and dexamethasone in newly-diagnosed patients ineligible for a bone marrow transplant.