Merck & Co sticks with high-risk obesity and cholesterol drug plans

US-based pharmaceutical company Merck & Co has said it will continue development of experimental drugs for cholesterol and obesity, which are similar to others currently beleaguered by safety issues.

In a meeting held on 11 December, Merck & Co told investors that the highlighted treatments are among seven investigational compounds undergoing late-stage clinical testing. The company said it would submit two of these, including a weight-loss treatment, for regulatory approval in 2008.

High-risk CETP-inhibitor
In 2008, Merck & Co will begin late-stage patient studies of anacetrapib, which is designed to raise high-density lipoprotein (HDL, or good cholesterol) levels in the blood, while lowering low-density lipoproteins (LDL, or bad cholesterol). Researchers believe that raising HDL levels could further reduce the risk of heart problems in advance of traditional statins, which generally only lower LDL levels.

The risk with anacetrapib could be great. Pfizer wasted millions in an effort to develop a similar compound called torcetrapib, which failed in late-stage clinical trials after a study showed an increased risk of death. Torcetrapib was also associated with increasing blood pressure in patients.

Merck & Co stated that anacetrapib has not been associated with an increase in blood pressure in mid-stage studies to date. It now plans to begin a programme of studies next year for the drug, which would measure key safety effects, such as changes in blood pressure. The company said that the drug is still several years off from reaching the market.

Peter Kim, Merck & Co's president of research, told investors: "Anacetrapib had no effect on blood pressure. These effects of torcetrapib appear to be due to an off-target, CETP-independent mechanism."

Obesity treatment
At the meeting, Merck & Co also revealed it was developing an anti-obesity drug called taranabant. The company initiated a phase III study in 2006 and planned to submit it for FDA approval in 2008.

Early studies of taranabant have shown it can help people to lose weight, but like sanofi-aventis' (S-A) own weight loss drug Acomplia (rimonabant), studies have linked it to an increase in psychiatric side effects.

An FDA advisory committee rejected Rimonabant earlier in 2007. The agency cited psychiatric side effects and S-A withdrew its application. Acomplia is available in Europe, but regulators have warned that people with depression should not take the drug.

Despite the clinical evidence, Merck & Co has decided to continue development of taranabant, citing animal studies suggesting it is different from rimonabant. However, the late-stage study includes lower doses of taranabant than those studied in a mid-stage patient trial.

Other drug news
Merck & Co anticipates regulatory action on two pending drug applications during 2008: an injectable version of its Emend (aprepitant) anti-nausea drug; and Cordaptive (extended release niacin/ laropiprant), which is designed to raise good cholesterol by a different mechanism than anacetrapib.

The company said it would make two additional FDA applications for new drugs: one for taranabant and one for MK-0524B, which would combine Cordaptive with simvastatin, a statin which lowers bad cholesterol.

Merck & Co concluded the meeting by saying it would file in December 2007 for FDA approval to widen the approved age range of women who can take the Gardasil cervical-cancer vaccine, to up to 45 years old. The vaccine is currently approved for girls and women aged between nine and 26 years.

The company will also submit data to the FDA regarding Gardasil's efficacy in males during 2008. It says that giving Gardasil to males would help prevent the spread of the virus that causes cervical cancer, while prevent genital warts in males caused by the virus strains targeted by the vaccine.

Shares in Merck & Co were recently trading down USD 0.26, or 0.4 per cent, to rest at USD 60.51.