The launch of Bristol-Myers Squibb and Merck & Co’s novel diabetes type 2 therapy, Pargluva (muraglitazar), could be pushed back as much as a year after an approvable letter from the US Food and Drug Administration has requested more clinical trial data before full clearance is considered.

The companies are hoping to market Pargluva as the first in a new class of diabetic agents, known as peroxisome proliferator-activator receptor agonists. This delay, although unsurprising given that an FDA advisory committee voiced concerns over potential cardiovascular effects associated with the agent earlier this year [[090905c]], will come as a bit of a blow to the firms.

Both B-MS and Merck are facing growing generic competition to some of their key drugs, and will therefore have been hoping to claw back some sales with the launch of Pargluva as soon as possible.

But investors stayed calm on the news, with shares of B-MS closing down $0.26 to $22.22, and Merck & Co dipping just $0.03 to $27.05, reflecting the fact that the FDA’s decision was as expected.