Pfizer Announces Results For Late-stage OPT Retreatment Study Of Tofacitinib

(RTTNews) - Pfizer Inc. (PFE) announced detailed results from the Oral treatment Psoriasis Trial or OPT Retreatment study (A3921111), a Phase 3 study investigating tofacitinib for the treatment of adult patients with moderate-to-severe chronic plaque psoriasis.

This three-period study showed that tofacitinib, as a 5 mg or 10 mg pill taken twice daily, met its two primary efficacy endpoints. The safety profile of tofacitinib in OPT Retreatment was consistent with previous studies and there were no new safety findings in this trial.

The first primary endpoint of OPT Retreatment evaluated the maintenance of clinical response in patients who remained on tofacitinib after an initial treatment phase compared to patients who were switched to placebo (withdrawal phase).

The second primary endpoint examined patients who lost half of their original clinical response during the withdrawal phase, and measured the proportion of these patients who regained their original clinical response after restarting treatment with tofacitinib.

Throughout the study, the efficacy response was measured by the proportion of subjects achieving a Physician's Global Assessment (PGA) response of "clear" or "almost clear" skin and the proportion of subjects achieving at least a 75% reduction in the Psoriasis Area and Severity Index (PASI75), two commonly used measures of efficacy in psoriasis.

Tofacitinib, an oral Janus kinase or JAK inhibitor, is part of a new class of medicines in development for the treatment of moderate-to-severe plaque psoriasis. Top-line results from OPT Retreatment were previously announced in October 2013, and the detailed results of this study were shown today in an oral presentation during the 11th European Academy of Dermatology and Venereology or EADV Spring Symposium in Belgrade, Serbia.

OPT Retreatment was a Phase 3 randomized, double-blind, three-period, parallel group, placebo-controlled 56-week study. This study evaluated the efficacy and safety of the withdrawal and retreatment with tofacitinib 5 mg and 10 mg twice daily compared to placebo in 674 adult patients with moderate-to-severe chronic plaque psoriasis. During the first period (24 weeks), which was a secondary endpoint of this study, patients were treated with either tofacitinib at a dose of 5 mg or 10 mg twice daily in a blinded manner.

Psoriasis is a chronic, immune-mediated disease, affecting primarily the skin but also other organs, such as nails and joints. It affects approximately two-to-three percent of people worldwide and 7.4 million people in the United States.