Merck said Thursday morning it is discontinuing two Phase 3 trials of Keytruda, the world’s top-selling medicine, after independent data monitoring committees determined they weren’t going to succeed.
The two trials — KEYNOTE-867 and KEYNOTE-630 — are a small piece of the clinical landscape for the medicine, which is currently being tested in more than 1,600 studies by a long list of drugmakers seeking to pair up their drugs with the anti-PD-1 therapy that reeled in $7 billion in second-quarter sales.
Nonetheless, it marks a setback for attempting to bring the treatment to even more patients, including those with earlier stages of non-small cell lung cancer, or NSCLC.
KEYNOTE-867 was testing Keytruda in combination with stereotactic body radiotherapy for stage 1 or 2 (stage 2B N0, M0) NSCLC. The combo did not show an improvement in event-free survival or a key secondary endpoint of overall survival at the time of a planned interim analysis, Merck said. The drugmaker has described the trial as one of its “key studies” in early stages of NSCLC.
Meanwhile, KEYNOTE-630 was investigating Keytruda as an adjuvant treatment for high-risk locally advanced cutaneous squamous cell carcinoma following surgery and radiation. The risk/benefit profile wasn’t good enough to continue the trial as it didn’t cross the threshold for statistical significance on recurrence-free survival, according to the data monitoring committee. Results also “did not favor” Keytruda over placebo on the secondary endpoint of overall survival.
The New Jersey pharma giant has reeled in more than 35 indications across more than 15 different tumor types for Keytruda, and it has spent more than $45 billion developing it to date. Merck expects to devote an additional $20 billion to Keytruda by 2030, CEO Rob Davis said at a PhRMA event on the sidelines of this year’s American Society of Clinical Oncology confab.
The drug is set to lose key market exclusivity in 2028, but a subcutaneous formulation could have separate patent protection well beyond that. Some companies are exploring biosimilars, and others are hoping to finally mount a head-on challenge.