Merck & Co is to trim up to 22% from the price of its once-daily non-nucleoside reverse transcriptase inhibitor, Stocrin (efavirenz), for use in the developing world and those countries hardest hit by the HIV epidemic.

Stocrin will now be priced at $0.76 per day for the 600mg formulation – totaling $277.40 for one year’s therapy - while the price of the 200mg formulation has been trimmed 22% to $1.08 per day and about $394.20 per patient per year.

Merck, which says it has been able to drive this pricing change because of cost savings triggered by new efficiencies in its manufacturing processes, also hopes to shave more off the cost of Stocrin in the future as improvements continue. However, the price cut is restricted to big orders and does not include either shipping or insurance, says a CNN report, which it notes is expected to add another 10% to the final cost.

The move follows global pressure on firms to cut drug prices to that of their generic rivals in the developing world. In November 2003, the Clinton Foundation announced agreements with Cipla and a number of other pharmaceutical companies to slash the prices of antiretroviral medicines used to treat HIV/AIDS by more than 50% from lowest market rates. More recently, this agreement was expanded to include efavirenz and GlaxoSmithKline’s Ziagen (abacavir) as a first step to lower the cost of second line treatment: the prices for these drugs were reduced by more than 30% from current market rates, making it $240 per year.

Dr Peter Piot, Executive Director of the Joint United Nations Program on HIV/AIDS (UNAIDS), gave a warm welcome to Merck’s decision to cut Stocrin’s price, but stressed that this trend must accelerate to achieve “universal access to HIV prevention, treatment and care for all who need it by 2010.”