Shares in NicOx fell to their lowest level in nearly two-and-a-half years after the French biotechnology firm stated that partner Pfizer will discontinue late-stage development of an experimental glaucoma drug in Asia.

Pfizer will not launch a Phase III programme of PF-03187207 in Asia after a mid-stage study of the compound in 112 Japanese patients failed to meet its primary endpoint at 28 days. That trial compared the safety and efficacy of various doses of PF-03187207, a nitric oxide-donating prostaglandin analogue, to Pfizer’s own Xalatan (latanoprost) in patients with primary open-angle glaucoma or ocular hypertension.

The news is not overly surprising, given that the New York-based drugs major decided in May not to undertake late-stage testing of the drug outside of Asia following results of a different 215-patient Phase II trial in the USA. The companies have now entered into “active discussions” for the French firm to buy back the global rights to PF-03187207, which chief executive Michele Garufi said “has a certain commercial potential which should be realised”.

NiCox added that its ophthalmology collaboration with Pfizer, which was extended in January, will now concentrate on identifying nitric oxide-donating compounds for diabetic retinopathy. Mr Garufi said that the firms anticipate selecting a lead compound in the first half of 2009.