Right now, Roche’s Tecentriq is the only immuno-oncology drug approved in triple negative breast cancer. And it looks like it’ll stay that way for awhile.
Merck's steamroller Keytruda turned in a rare phase 3 trial miss, failing to extend the lives of previously treated patients with the tough-to-tackle breast cancer form. The company's release late Monday was light on the details, which will roll out at a future medical meeting.
That means Keytruda won’t be joining Tecentriq on the list of approved triple negative breast cancer drugs—at least in the short term. But Roy Baynes, Merck senior vice president and head of global clinical development, stressed that the disease gets even more difficult to treat the second and third time around. And that made this second-line trial a particular challenge for Keytruda, or any treatment for that matter.
“Metastatic triple-negative breast cancer is an aggressive and challenging disease to treat, especially after progression on initial standard-of-care treatment,” he said in a statement.
Tecentriq, meanwhile, picked up an FDA green light in March for use in new patients. The OK followed data showing that the checkpoint inhibitor coupled with Celgene chemo drug Abraxane pared down the risk of disease worsening or death by 20% in patients whose tumors express the PD-L1 protein. Roche has that market all to itself for now—and that's something Tecentriq can’t boast in many cancer types, thanks in part to Keytruda’s wide collection of indications.
Of course, Merck is looking to bring Keytruda into triple negative breast cancer earlier in treatment, as Baynes noted, and it’s also testing the drug alongside chemo—a tactic that’s yielded stronger results than monotherapy in some tumor types, including non-small cell lung cancer. Three of the drugmaker's ongoing Keytruda studies could underpin FDA applications, including Keynote-522, which is examining Keytruda-plus-chemo in patients before and after surgery, more properly known as the neoadjuvant and adjuvant settings.