Even after Merck & Co.’s Keytruda has climbed to the top of the industry’s sales charts and racked up dozens of FDA-approved indications, the drug is showing it still has unfinished business.
In the Keynote-B96 study, a Keytruda-based regimen has shown a statistically significant overall survival (OS) benefit in all comers with platinum-resistant recurrent ovarian cancer, Merck said in an Oct. 16 release.
The trial measured the effects of Keytruda in combination with chemotherapy—with or without Roche’s Avastin (bevacizumab)—against a control regimen of placebo and chemotherapy, again with or without Avastin.
Previously, Merck hailed a primary endpoint win in the study, with the Keytruda regimen demonstrating its ability to extend patients’ progression-free survival (PFS) in those whose tumors expressed PD-L1 and in all comers. At the time of the primary endpoint readout in May, Merck also said the Keytruda regimen extended OS in patients whose tumors expressed PD-L1.
Now, Merck is celebrating a positive result for a secondary endpoint, OS, in all comers in the study regardless of their PD-L1 expression levels.
The study results “mark the first time ever that an immune checkpoint inhibitor-based regimen has demonstrated the potential to help all patients with platinum-resistant recurrent ovarian cancer,” Gursel Aktan, M.D., Ph.D., vice president of global clinical development at Merck Research Laboratories, said in a statement.
“These women face a very poor prognosis with limited options for treatment, and this impactful news is a testament to our tireless commitment to exploring new options for patients with gynecologic cancers who face a critical unmet need,” Aktan added.
Despite boasting more than 40 FDA approvals, Keytruda hasn’t been able to crack into ovarian cancer during its impressive market run. After the prior readout in the Keynote-B96 study, Merck pledged to share detailed results at medical meetings and with regulators in pursuit of potential approvals.
Elsewhere in ovarian cancer, Merck’s AstraZeneca-partnered Lynparza carries three FDA approvals. Merck is additionally testing a Daiichi Sankyo-partnered antibody-drug conjugate in patients with platinum-resistant ovarian cancer.
In another study, a Keytruda regimen extended PFS in patients with BRCA non-mutated advanced epithelial ovarian cancer, but it failed to notch an OS win. The trial tested Keytruda plus chemotherapy followed by Lynparza maintenance—with or without Avastin—against chemotherapy alone in those patients.
After that result, Merck said Keytruda’s role as a potential treatment for the study's target population was “uncertain.”