Merck could soon join rival Bristol-Myers Squibb in making immunotherapy an option for kidney cancer patients who have never had treatment before.
Merck (NYSE: [[ticker:MRK]]) reported today that its blockbuster drug pembrolizumab (Keytruda) has hit its marks much earlier than expected in an 861-person Phase 3 study called Keynote-426. Merck tested a combination of pembrolizumab and axitinib (Inlyta), an approved kidney cancer drug from Pfizer, comparing it with sunitinib (Sutent), another approved drug that works in similar fashion to axitinib. The combination performed better than sunitinib in three measures: patients lived longer overall, and their cancer stayed in remission longer—the two main goals of the study—and more patients had at least some kind of positive effect, which was a secondary goal.
The news “pushes up the timelines,” and Merck could end up with a combination product on the market nine to twelve months earlier than expected, wrote ISI Evercore analyst Umer Raffat in a note to investors.
Pembrolizumab blocks the protein PD1, which some tumors use to hide from the immune system. Thanks to pembrolizumab and nivolumab (Opdivo), from BMS (NYSE: [[ticker:BMY]]), immunotherapy has quickly gone from a last-ditch option to one of the first drugs doctors prescribe for some advanced cancers.
Merck said an independent committee stopped the study early because of the significant benefit; the company did not expect results until 2019 or 2020. There’s a caveat to the good news: Merck did not disclose specific data. It did say that the positive results were consistent across different types of patients.
It remains to be seen what “consistent” means specifically, but Raffat noted that Bristol, testing its own anti-PD1 blockbuster nivolumab in the same population, saw inconsistent results among patients with different risk levels. Bristol tested nivolumab in combination with its other approved immunotherapy ipilumumab (Yervoy) and won FDA approval earlier this year in first-line kidney cancer—but only in patients who have a middling to poor prognosis.
Ipilumumab attacks cancer via the CTLA4 protein, not the PD1 protein. Both proteins are immune “checkpoints,” and the drugs that block them are checkpoint inhibitors. The FDA recently approved its sixth, and the invention of checkpoint inhibitors received high recognition, with two pioneers winning this year’s Nobel Prize in medicine.
