Merck's Keytruda Achieves Landmark Overall Survival Benefit in Ovarian Cancer Study

Merck & Co.'s blockbuster cancer immunotherapy Keytruda (pembrolizumab) has demonstrated a significant overall survival (OS) benefit in patients with platinum-resistant recurrent ovarian cancer, marking a potential breakthrough in the treatment of this challenging disease.

Keytruda Regimen Shows Promise in All-Comer Population

In the phase 3 Keynote-B96 study, a Keytruda-based regimen showed a statistically significant OS benefit in all patients with platinum-resistant recurrent ovarian cancer, regardless of their PD-L1 expression levels. This result follows a previous announcement of positive progression-free survival (PFS) data from the same trial.

The study evaluated Keytruda in combination with chemotherapy, with or without Roche's Avastin (bevacizumab), against a control regimen of placebo and chemotherapy, also with or without Avastin. Dr. Gursel Aktan, vice president of global clinical development at Merck Research Laboratories, highlighted the significance of these results, stating, "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."

Implications for Ovarian Cancer Treatment Landscape

This achievement represents the first time an immune checkpoint inhibitor-based regimen has shown potential benefit for all patients with platinum-resistant recurrent ovarian cancer. Despite Keytruda's success in various cancer types, with over 40 FDA approvals, it has not yet secured an indication in ovarian cancer.

The positive results from Keynote-B96 could pave the way for Keytruda's entry into the ovarian cancer treatment paradigm. Merck has stated its intention to share detailed results at upcoming medical meetings and with regulatory authorities to pursue potential approvals.

Merck's Ongoing Efforts in Ovarian Cancer

While Keytruda seeks to establish its role in ovarian cancer treatment, Merck is not putting all its eggs in one basket. The company's portfolio includes Lynparza (olaparib), partnered with AstraZeneca, which already holds three FDA approvals in ovarian cancer. Additionally, Merck is exploring a Daiichi Sankyo-partnered antibody-drug conjugate in patients with platinum-resistant ovarian cancer.

However, not all of Merck's ovarian cancer efforts have met with success. In a separate study, a Keytruda regimen extended PFS in patients with BRCA non-mutated advanced epithelial ovarian cancer but failed to demonstrate an OS benefit. This mixed result underscores the complexities of treating ovarian cancer and the ongoing need for innovative approaches in this field.