Pfizer: FDA request may delay tofacitinib's approval but hopes for the drug remain undiminished

The latest trial results for Pfizer's tofacitinib add to the drug's wealth of clinical data as it sits on the brink of US entry. Nevertheless, Pfizer has revealed that the FDA has requested further data analysis on tofacitinib. While this is likely to extend the FDA's period of review, Datamonitor continues to anticipate tofacitinib's US launch in Q1 2013.

The trial results show that tofacitinib has demonstrated superiority to methotrexate, an oral drug typically selected at first-line non-biologic treatment in rheumatoid arthritis (RA).

In the ongoing ORAL Start study, 958 methotrexate-naive patients with moderate to severe active RA were randomized to receive methotrexate or tofacitinib (5mg or 10mg). Both doses of tofacitinib met the primary endpoints of the trial and, more importantly, no new safety signals emerged. The data indicate that tofacitinib could be selected at first line over methotrexate.

Methotrexate's historical use and the anticipated high price of tofacitinib relative to methotrexate may limit uptake. Nevertheless, these latest data further support tofacitinib's potential to be positioned ahead of biologics. Pfizer will present its clinical findings at an upcoming rheumatology meeting.

Pfizer submitted tofacitinib to the FDA for approval as a potential treatment for adult patients with moderate to severe active RA in December 2011. The company intends to fulfill the regulator's request for further analysis of the drug in early August, but this will be just a few weeks before tofacitinib's August 21 Prescription Drug User Fee Act (PDUFA) date. As such the FDA is likely to require more time to review tofacitinib, therefore delaying approval.

Tofacitinib's potential to revolutionize the rheumatoid arthritis market has been widely acknowledged, and expectations are high. Its impressive efficacy data across multiple patient groups, efficacy in-line with leading biologic Enbrel (etanercept; Amgen/Pfizer), positive outcome in an active comparator trial versus first-line contender Humira (adalimumab; Abbott/Eisai), and positive FDA advisory opinion in May 2012 are all indicative of the drug's commercial potential. Indeed, despite the August PDUFA date likely being pushed later into 2012, Datamonitor anticipates a positive decision from the FDA and a launch in Q1 2013.

If approved, oral tofacitinib would be a strong competitor to biologics such as Enbrel and Humira. Datamonitor forecasts strong sales, reaching $695m in the US by 2020.