Merck & Co has started a Phase II trial of MK-0354, a potential novel treatment atherosclerosis and other related disorders, and also announced the discovery of a new class of antibiotic.

MK-0354, which targets an unidentified G protein-coupled receptor, was originally discovered by Arena Pharmaceuticals and licensed to Merck in October 2002. It is thought to play a role in regulating plasma lipid profiles, including high-density lipoprotein or ‘good’ cholesterol, and be responsible for the HDL-raising activity of the cholesterol-lowering drug niacin.

While there are many effective drug to raise ‘bad’ or low-density lipoprotein cholesterol, few drugs exist that can raise the cardioprotective HDL form. Merck started a Phase I trial of the drug last year which demonstrated that MK-0354 was well-tolerated and orally-bioavailable.

One drug that claims to achieve the latter objective is Merck and Schering-Plough’s combination cholesterol drug Vytorin/Inegy (ezetimibe and simvastatin), with sales of $1 billion in 2005, while others in development include: another Merck product, MK-542A (Phase III); Pfizer’s torcetrapib (Phase III); Roche’s JTT-705 (Phase II); and Novartis’ D-4F (Phase I).

The start of the Phase II trial triggers a $4-million milestone payment to Arena.

Novel antibiotic

Meanwhile, Merck researchers report in Nature that they have discovered a new compound, called platensimycin, which represents only the third completely new class of antibiotic identified in the last 40 years.

They note that it acts in a way completely different from all existing antibiotic classes – inhibiting the synthesis of fatty acids – so could be an important new drug for resistant organisms, such as methicillin-resistant Staphylococcus aureus.

Platensimycin was discovered via a natural products screening programme at Merck, and is made in a strain of the bacteria Streptomyces platensis.