Pfizer has been boosted by the news that US regulators have given the green light to a new indication for its painkiller Lyrica which is now the only drug approved for fibromyalgia.

After a priority review, the US Food and Drug Administration has approved Lyrica (pregabalin) for the management of fibromyalgia, one of the most common chronic, widespread pain conditions which affects more than six million Americans, and is thought to result from neurological changes in how patients perceive pain. It is usually accompanied by poor sleep, stiffness, depression and fatigue and can hamper a patient's ability to work.

The label expansion for Lyrica, which is approved for the management of neuropathic pain associated with diabetic peripheral neuropathy and post-herpetic neuralgia, and for the adjunctive therapy for adults with partial onset seizures, means that Pfizer will benefit from even more sales of the blockbuster. More than five million patients worldwide have used Lyrica since it rolled out in the USA in 2005 and first-quarter sales this year were up 106% to $395 million.

Getting the fibromyalgia indication will stimulate Lyrica growth, acknowledged Bear Stearns analyst John Boris in a research note and being the first drug approved for the condition is a huge advantage. Competition in the future may come from the likes of Eli Lilly’s Cymbalta (duloxetine), Wyeth’s Pristiq (desvenlafaxine) and UCB’s Xyrem (sodium oxybate) but Pfizer has got a clear run for the timebeing.

FDA only gives approvable letter to maraviroc

However the FDA also had some very disappointing news for the New York-headquartered behemoth as it has only issued an approvable letter for its new HIV treatment Celsentri (maraviroc). The decision is something of a shock as the agency’s Antiviral Drugs Advisory Committee gave a unanimous recommendation for approval of the drug less than two months ago.

Pfizer said little about what further information the FDA could want on the drug, merely stating that it is continuing its discussions with the agency “to address outstanding questions and finalise the product labelling”. The drug has been available in 30 countries via an expanded access programme since earlier this year and more than 2,000 individuals have received maraviroc, the first in a new class of HIV/AIDS treatments called CCR5 antagonists, through clinical trials.