Merck, the last big firm standing in the once-hyped CETP field, has opted against filing for approval of anacetrapib. The Big Pharma reached the decision after going over a mixed set of data from its big bet on a phase 3 program.

The door to a filing for approval swung open unexpectedly in June when Merck bucked the trend by reporting its long-running, 30,000-patient study met its primary endpoint. However, hopes that Merck could succeed where Eli Lilly, Pfizer and others had failed were tempered by the small improvement against the main goal, inability to move the needle against secondary endpoints and a safety concern.

That left Merck with a drug that may have snuck past regulators but struggled to win market share. Now, Merck has decided its best option is to cut its losses and move on. 

"After comprehensive evaluation, we have concluded that the clinical profile for anacetrapib does not support regulatory filings," Merck's Roger Perlmutter, M.D., Ph.D., said in a statement.

Merck’s move nearly wraps up the drawn-out demise of CETP inhibitors. Setbacks in the clinic for Roche and Pfizer indicated years ago that the field may fail to live up to expectations. But Lilly and Merck forged ahead, driven by a belief those flops stemmed from shortcomings of the drugs, not the idea of CETP inhibitors. Lilly’s belief in that was scuttled by its own clinical data in 2015.

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Merck got closer than its fallen rivals to getting a CETP inhibitor to the finish line. A statistically significant decline in major coronary events marked a rare late-phase success for the field, but ultimately, the overall data package was too weak for Merck to justify filing for approval.

Merck’s departure from the stage leaves a couple of small companies to fly the flag for CETP inhibitors. DalCor Pharmaceuticals is putting a drug it picked up from Roche, dalcetrapib, through phase 3. And Korea's Chong Kun Dang Pharmaceutical is running a midphase trial of its CETP drug in combination with statins.