Merck has announced plans to launch three pivotal Phase III clinical trials for its immunotherapy Keytruda as a combination treatment for prostate cancer after the drug demonstrated anti-tumour activity in an early-stage trial.
Keytruda showed activity when given in conjunction with various other agents to patients with metastatic castration-resistant prostate cancer (mCRPC) in the Phase Ib/II KEYNOTE-365 trial.
The 400-patient umbrella trial involved combinations with Lynparza, enzalutamide, docetaxel and prednisone. The safety profile of the combinations was observed to be consistent with that of the individual agents.
Merck Research Laboratories senior vice-president Roy Baynes said: “At the core of our research program is a commitment to investigate the potential of Keytruda, both as combination and monotherapy, to serve as a foundational treatment, especially for cancers where additional therapies are needed.
“These promising data presented at ASCO GU coupled with the significant unmet medical need in patients with metastatic castration-resistant prostate cancer, propelled us to initiate three new Phase III trials to further evaluate these KEYTRUDA combination regimens.”
One of the new Phase III trials, KEYLYNK-010, will assess the safety and efficacy of Keytruda and Lynparza combination in 780 mCRPC patients.
The trial is scheduled to begin in May this year and is expected to be concluded by September 2022.
Meanwhile, the randomised, double-blind KEYNOTE-921 trial will study Keytruda in combination with docetaxel and prednisone in a total of 1,000 participants.
KEYNOTE-921 is set to be completed in February 2023.
Merck will also study Keytruda plus enzalutamide in the third KEYNOTE-641 trial involving 1,200 participants. Scheduled to be initiated in July this year, this trial will be completed by April 2024.
Currently, the drug is being evaluated for prostate cancer in multiple trials, including Phase II KEYNOTE-199 and Phase III PROfound and PROPEL trials.