Time for GSK to stop dreaming about Blenrep

GSK’s Blenrep was the first BCMA-directed agent to reach the market, but this is not what the drug will be remembered for – the failure of a crucial confirmatory trial means the antibody-drug conjugate could be pulled from the market. Blenrep has always sat among the least impressive of the anti-BCMA pack, a weakness that has now been laid bare in the disastrous Dreamm-3 readout. The third-line multiple myeloma trial pitted Blenrep against Bristol Myers Squibb’s Pomalyst; success could have converted Blenrep’s fourth-line accelerated approval into a full green light. But the primary endpoint was a clear bust, and while response rates might have trended in Blenrep’s favour the admittedly immature overall survival result is also pointing the wrong way. Regulators will surely have to reconsider the drug's availability; two looming second-line readouts potentially offer redemption but with several other much better BCMA options out there, this feels like the end of the road for Blenrep. This represents another black mark against GSK’s attempts to build a position in cancer, though it perhaps helps explain why executives stressed a “pragmatic approach” to oncology investment on last week's earnings call, and emphasised that the group's main focus was elsewhere.