GlaxoSmithKline and partner Pozen Pharmaceuticals have been dealt another blow by the US Food and Drug Administration in their bid to get approval for the migraine drug Trexima.

Pozen said that the agency has completed its initial review of the firms’

response to an approvable letter issued in June for Trexima (sumatriptan

plus naproxen). The FDA feels the reply “is not yet complete” and has

“requested additional analyses and supporting information.”

On receipt of the approvable letter in the summer, Pozen plunged over 60%, but since then the stock has rallied. However, news of the latest missive from the FDA sent the shares down over 9%, although they recovered to finish just 2% down on Wednesday at $16.09.

Pozen and GSK were upbeat, saying that they will submit the revised

response before the end of 2006 so that the FDA can more fully assess the

relative safety profile of Trexima, which combines GSK’s Imitrex (sumatriptan) with the nonsteroidal anti-inflammatory, naproxen sodium, and uses Pozen’s RT Technology allowing drugs to quickly dissolve in the stomach.

In a conference call, John Plachetka, Pozen’s chief executive, said that

the problem centred around the way that the new data was presented as

opposed to any issue of safety. GSK and Pozen concluded by saying that

they continue to believe that the data for Trexima “demonstrate superior

efficacy and a safety profile comparable to sumatriptan” and they remain

hopeful of a launch in the third quarter of 2007.

New Tykerb study initiated

On a more positive note, GSK said it has initiated a Phase III study,

called TEACH, to investigate whether adjuvant treatment with its

experimental drug Tykerb (lapatinib) will improve disease-free survival in

women with early-stage HER2(ErbB2)-positive breast cancer. Approximately 3,000 women will be enrolled from more than 450 centres in more than 30 countries.

Tykerb has been filed in the USA and Europe for use in combination with Roche’s Xeloda (capecitabine) for advanced breast cancer in women who have already received other treatments. Many observers see the drug as a potential rival to Roche’s blockbuster breast cancer drug Herceptin

(trastuzumab), with the advantage of being an orally-active drug while

Herceptin is dosed by injection. Both block the HER-2 receptor, while

Tykerb also has activity against the epidermal growth factor receptor