Merck & Co. presents positive Phase IIb data for CETP inhibitor

Data from a Phase IIb study showed that Merck & Co.'s cholesteryl ester transfer protein (CETP) inhibitor, anacetrapib (MK-0859), raised levels of HDL cholesterol in patients with dyslipidemia by as much as 139 percent and did not increase their blood pressure, compared with placebo. Analysts estimate that a marketed HDL-raising drug could have peak annual sales of more than $15 billion.
As part of the study, 589 patients with dyslipidemia were randomised to receive placebo, or one of four doses of anacetrapib alone or in combination with Pfizer's Lipitor. After eight weeks, patients who received anacetrapib monotherapy had increases in HDL cholesterol ranging from 44 percent to 139 percent, compared with an increase of 4 percent for those in the placebo group. The results showed that patients in the anacetrapib monotherapy group experienced decreases in LDL cholesterol ranging from 16 percent to 40 percent, compared with 2 percent in the control group.
Additionally, Merck noted that the combination of anacetrapib plus Lipitor resulted in "significant incremental reductions in LDL-C and increases in HDL-C compared to atorvastatin alone." Dan Bloomfield, a senior director with Merck Research Laboratories, commented that "having a compound like ours, that doesn't raise blood pressure, may give us an opportunity to test the mechanism of a compound that doesn't have off-target toxicity." Bloomfield added that "the ultimate benefits of CETP inhibition on clinical outcomes have not yet been established."
However, Merck indicated that it plans to evaluate data on Pfizer's experimental CETP inhibitor torcetrapib, which will be presented at an upcoming meeting, before deciding whether to proceed with further testing of anacetrapib. Pfizer halted clinical development of its compound in December after the treatment was linked to an increased risk of death.