An experimental GlaxoSmithKline treatment for multiple myeloma has achieved the main goal of a key study, and the drug maker plans to file for regulatory approval by the end of this year.
GlaxoSmithKline (NYSE: GSK) said Friday that treatment with its drug, belantamab mafodotin, showed a “clinically meaningful overall response rate” in the study. The British pharmaceutical company did not report additional details other than to say that its safety and tolerability were consistent with an earlier test of the drug.
Results from the earlier Phase 1 test were published in March in the Blood Cancer Journal. The data showed that 21 of the 35 patients who received the drug (60 percent) showed a partial response or better. The median length of time that patients lived without the cancer worsening was 12 months; the median duration of response to the drug was 14.3 months. GSK said Friday that safety and efficacy data for the drug’s latest test will be submitted for presentation at an upcoming scientific meeting.
Multiple myeloma is a type of blood cancer that forms in the plasma cells. The GSK drug was tested in an open-label study that evaluated two doses of the drug. The Phase 2 study enrolled 196 patients whose disease did not respond to two types of cancer treatments: a proteasome inhibitor, which blocks cellular structures that are key to cancer cell survival, and an antibody drug that targets the CD38 protein, which is widely expressed on multiple myeloma cells.
Belantamab mafodotin is a type of drug called an antibody drug conjugate. These drugs combine the targeting properties of an antibody with powerful cancer-killing toxins. The GSK drug targets B cell maturation antigen (BCMA), a protein expressed on the surface of cancerous plasma cells. GSK developed the drug using technology licensed from Seattle Genetics (NASDAQ: SGEN) and BioWa.
GSK isn’t the only company that’s targeting BCMA. Bluebird Bio (NASDAQ: BLUE) and partner Celgene (NASDAQ: CELG) are conducting a pivotal study of BCMA drug bb2121. The partners are also developing another BCMA drug, bb21217. Celgene is developing a third program, JCARH125, which came to the company via its acquisition of Juno Therapeutics last year.
Johnson & Johnson (NYSE: JNJ) is in the BCMA race with a drug whose rights it acquired in a deal with Chinese company Nanjing Legend. The drug, LCAR-B38M, is in Phase 2 testing. Meanwhile, Amgen (NASDAQ: AMGN) is testing antibody drug AMG-420, which hits BCMA as well as a second target on T cells. The Amgen drug is in Phase 1 testing.
GSK has been rebuilding its cancer drug portfolio after selling its marketed cancer drugs to Novartis (NYSE: NVS) in a 2014 deal. But GSK made a big move to return to cancer drugs last year, reaching a $5.1 billion deal to acquire Tesaro, a Waltham, MA, company that commercialized a type of cancer drug called a PARP inhibitor.