- Merck has pulled the plug on a Phase 3 study of its Alzheimer's candidate verubecestat, halting further work after an independent data monitoring committee judged there to be "virtually no chance of finding a positive clinical effect."
- The Phase 3 study in question, known as EPOCH, was testing verubecestat against placebo in patients with mild-to-moderate Alzheimer's disease. The data monitoring committee recommended Merck's other late-stage trial studying verubecestat in prodomal patients continue unchanged.
- Merck stock opened down about 1% on the news in Wednesday morning trading. While Merck has positioned itself well in immuno-oncology with Keytruda (pembrolizumab), verubecestat was one of the pharma company's leading pipeline candidates.
Alzheimer's disease continues to bedevil drugmakers' best efforts to find a treatment with efficacy that holds up to the scrutiny of a Phase 3 trial.
Verubecestat, like other Alzheimer's drug candidates before it, is designed to disrupt the formation of beta-amyloid plaques in the brain. Build-up of these plaques is thought to contribute to development of the neurodegenerative disease, although that hypothesis took a major hit after the failure of Eli Lilly's solanezumab in late-stage testing last year.
Merck will continue to study verubecestat in the Phase 3 APECS study, which is set to read out in February 2019. That study will investigate the drug as a treatment for prodromal Alzheimer's, an earlier stage of the disease characterized by the presence of objective memory problems but otherwise normal daily functioning.
While the data monitoring committee saw no hope of achieving positive efficacy results in EPOCH, the committee found safety signals were not threatening enough to warrant halting APECS as well.
Analysts from Jefferies believe the news on EPOCH will have only a limited impact on future revenue forecasts for Merck, yet think market sentiment around the company may suffer as the setback likely means greater dependence on Keytruda.
Notably, the analysts don't see much read-through to other BACE inhibitors in development. AstraZeneca and Eli Lilly currently have a compound in Phase 3 trials for early-stage Alzheimer's, with an expected readout in 2019. Johnson & Johnson and the team of Biogen and Eisai also have candidates moving through development.
Alzheimer's drug development faces a crucial year in 2019, when Biogen expects to have data on its closely watched aducanumab — now one of the leading candidates in the Alzheimer's field after solanezumab's latest failure.