- GlaxoSmithKline plans to submit an experimental myeloma drug for U.S. approval later this year, announcing Friday a Phase 2 study testing the antibody-drug conjugate succeeded.
- The drug, dubbed belantamab mafodotin, was hand-picked for rapid development by GSK's R&D chief Hal Barron soon after he took the position at the British pharma in late 2017. Three studies testing the BCMA-targeting medicine are now recruiting, with five Phase 3 trials planned to start in the next several years.
- No detailed data from the mid-stage test were disclosed Friday, but GSK said belantamab mafodotin helped to check study participants' multiple myeloma in a result it called "clinically meaningful."
GSK is one of several large pharmaceutical companies investing in multiple myeloma drugs that target the B-cell maturation antigen, or BCMA.
Found on the surface of proliferating plasma cells, BCMA is thought to be a particularly important protein due to its role in promoting cell growth and survival.
In the field of CAR-T cell therapies, BCMA has emerged as the next target of opportunity and is the focus of expensive development efforts by Celgene and Johnson & Johnson.
GSK's approach is different, using what's known as an antibody-drug conjugate to go after BCMA. Belantamab mafodotin combines an antibody designed to target BCMA with a toxic compound that's linked using technology licensed from Seattle Genetics.
Notable anti-BCMA therapies in development
|Submission planned for year's end 2019
|KarMMa study ongoing, submission planned for H2 2020
|Data presented at ASH. Phase 1b/2 study recruiting
|Phase 1 results presented at ASCO
|Phase 2 study recruiting
SOURCE: Companies, clinicaltrials.gov
Most of the current BCMA efforts are aimed at treating very sick multiple myeloma patients whose cancers have come back or who have become resistant to one of the many drugs currently approved for the disease.
In its Phase 2 study, GSK tested belantamab mafodotin in 196 patients previously treated with at least three other drugs and are refractory to two of the main treatment classes now available.
The primary measurement looked at was the overall response rate to treatment, data which GSK said would be the basis of regulatory applications beginning later this year.
Earlier testing showed 60% of patients responded to treatment with belantamab mafodotin. Median progression-free survival, or the time until disease worsening or death, extended out to one year. Most experienced side effects, including low blood platelet counts and anemia.
Partly because of that initial data, Hal Barron, GSK's top scientist, selected belantamab mafodotin as a key asset in a pipeline revamp GSK CEO Emma Walmsley began in 2017. Resources and employees freed up by cuts elsewhere were put into work on priorities like belantamab mafodotin and another drug Barron favored, called GSK3196165. (Mixed results for the latter in mid-stage testing have raised some doubts, however.)
"[Belantamab mafodotin] continues to advance at an impressive pace and is a good example of our cultural progress in terms of improving our focus and investing behind our most promising assets," Barron said on a recent earnings call.
Success with the drug is also important for GSK's broader efforts in oncology, an area which it is trying to rebuild after a 2014 asset swap with Novartis left it with a reduced presence. It's since made cancer research a priority, and bought Tesaro and its PARP inhibitor Zejula (niraparib) for $5.1 billion last December.