NicOx S.A. has announced the results of a dose-ranging phase 2 study conducted with PF‑03187207 in Japanese patients with glaucoma by its partner Pfizer Inc. PF-03187207 is a nitric oxide-donating prostaglandin analog. The study was designed to compare the safety and efficacy of several doses of PF-03187207 to Xalatan (latanoprost) and enrolled 112 Japanese patients with primary open-angle glaucoma or ocular hypertension.
In terms of the reduction in diurnal intraocular pressure (IOP), compared to baseline, the two highest doses of PF‑03187207 showed an improvement over Xalatan 0.005% of up to 11%, although the study did not meet its primary endpoint at day 28. PF-03187207 appeared to be safe and well tolerated, with adverse events being mild.
In May 2008, NicOx announced the results of a 215 patient U.S. dose-ranging phase 2 study, in which the highest dose of PF-03187207 showed a 12% improvement over Xalatan 0.005% at day 28, but did not reach statistical significance. In both the Japanese and U.S. studies, PF-03187207 showed a 20% greater reduction in IOP at 20 hours post-dose compared to Xalatan 0.005%, which reached statistical significance in the U.S. study, suggesting a more sustained IOP lowering effect.
Following the results of the U.S. study, Pfizer decided not to launch a phase 3 program for PF-03187207 outside of Asia. After reviewing the results of this Japanese study, Pfizer has decided not to launch an Asian phase 3 program for PF-03187207. NicOx and Pfizer are currently in discussions regarding the rights to PF-03187207, to allow its potential continued development and commercialization. PF-03187207 is covered by the companies' August 2004 agreement.
Michele Garufi, Chairman and CEO of NicOx, commented: "We are encouraged that the results of the Japanese and U.S. studies are consistent and both suggest that nitric oxide donation may allow a more sustained intraocular pressure lowering effect. NicOx and Pfizer are in active discussions regarding the worldwide rights to PF-03187207, which we believe has a certain commercial potential which should be realized. We are also pleased by the progress that has been made in the research program focused on diabetic retinopathy, where we hope a lead compound will be selected in the first half of next year."
In January 2008, NicOx announced it had signed a one year extension of its March 2006 collaboration agreement, which grants Pfizer Inc the exclusive right to apply NicOx' proprietary nitric oxide-donating technology to drug discovery research across the entire field of ophthalmology.
Under this agreement, the joint NicOx-Pfizer research team will concentrate its efforts on an ongoing program to identify nitric oxide-donating compounds for diabetic retinopathy (see NOTE), with the aim of selecting a lead compound for development during the first half of 2009. Active research on these compounds was initiated following the signature of the March 2006 agreement and continues to make good progress. This agreement provides for total potential milestone payments of EUR 102 million for the successful full development and launch of the first program compound.
Pfizer has decided to no longer pursue the research on nitric oxide-donating prostaglandin analogs covered by this agreement.