Pfizer concludes phase 2 study of experimental glaucoma treatment

SOPHIA ANTIPOLIS, France — Higher doses of an experimental glaucoma treatment co-developed by Pfizer and NicOx have demonstrated significant reductions in diurnal IOP, with the highest dose yielding consistently more IOP reduction than latanoprost 0.005% among patients with primary open-angle glaucoma or ocular hypertension, according to a press release from NicOx.

However, at final follow-up, all of the experimental doses had not yielded a statistically significant improvement over latanoprost 0.005% for reducing elevated diurnal IOP.

The novel treatment, called PF-03187207, is a nitric oxide-donating prostaglandin for reducing IOP, the release said.

Pfizer's dose-ranging phase 2 study compared the safety and efficacy of PF-03187207 with Xalatan (latanoprost 0.005%, Pfizer) among 215 patients with primary open-angle glaucoma or ocular hypertension. In the study, the researchers randomly assigned patients to receive 28 days of treatment with either morning or evening doses of latanoprost 0.005% or one of five doses of PF-03187207. IOP was measured at 8 a.m., 10 a.m., 1 p.m. and 4 p.m. at baseline and on days 7, 14, 21 and 28, according to the release.

At final follow-up, all PF-03187207 doses had not yielded a statistically significant improvement over latanoprost 0.005% for reducing elevated diurnal IOP. However, the researchers observed statistically significant IOP-lowering advantages over latanoprost 0.005% on a number of secondary endpoints (P < .05).

Pfizer does not plan to initiate a global phase 3 development program for PF-03187207, but intends to continue its joint research program with NicOx to identify the most active nitric oxide-donating prostaglandin analogs for global development.

Pfizer is currently conducting a phase 2 study for PF-03187207 in Japan, with preliminary results expected later this year, according to the release.