Merck Drops CETP Inhibitor Anacetrapib

Merck & Co. has announced that it is not going forward with its investigational cholesteryl ester transfer protein (CETP) inhibitor anacetrapib, deciding against filing for approval with the US Food and Drug Administration (FDA).

This decision comes on the heels of multiple struggles with the therapy, including multiple testing misfires and pessimism about its future. Other CTEP inhibitors had already been abandoned by Pfizer, Roche, and Eli Lilly by the time phase 3 results were presented on anacetrapib.

“We are deeply grateful to the researchers and patients who participated in the anacetrapib clinical development program, and in particular the REVEAL outcomes study. Unfortunately, after comprehensive evaluation, we have concluded that the clinical profile for anacetrapib does not support regulatory filings,” Roger Perlmutter, MD, PhD, president of Merck Research Laboratories, said in a statement.

Merck announced positive results from the phase 3 REVEAL trial, but at the time, many financial experts doubted the drug’s ability to make it to market. The seeds of doubt had been planted by Merck’s non-commitment to filing despite reporting positive trial results, according to Morgan Stanley Equity Analyst David Resinger.

“The cautious language in the release indicates an unclear risk-benefit [ratio] in our view, which investors should pay attention to,” analysts from Jeffries, a global analyst firm, said at the time. "We have previously highlighted low expectations for REVEAL, given the prior failures of other products in the CETP class, only assigning a 25% probability of success in our model.”

The REVEAL trial examined the safety and efficacy of anacetrapib in roughly 30000 patients at high risk for cardiovascular events, with results reaching statistical significance, but mostly as a result of the trial’s design. Although it met its primary endpoint, the safety of CETP inhibitors has been a point of contention consistently.

This marks the second time in as many weeks that Merck has abandoned a therapy, after having dropped 2 of its hepatitis C treatments - grazoprevir/ruzasvir/uprifosbuvir (MK-3682B) and ruzasvir/uprifosbuvir (MK-3682C) - last week. The company cited the “evolving market” as the reason for their halting.

According to Perlmutter, Merck will continue to work in the cardiovascular space, working to add to its “numerous, important contributions to the treatment of cardiovascular disease.”