Confirming expectations aired during its second quarter conference call, Pfizer announced Tuesday that the FDA has delayed its review of the experimental rheumatoid arthritis drug tofacitinib. The drug was set for review this month, but Pfizer said in a statement that the Janus kinase, or JAK inhibitor, will now come under agency scrutiny November 21.

The company statement reiterated a point made in the July 21 earnings call – that the additional time is just to review supplemental information Pfizer submitted at the agency’s request, and that there were no calls for new or additional studies.

If approved, it would be the first new drug mechanism for the disease in a decade. An FDA advisory panel was lukewarm about the drug, even though it endorsed it in May, unconvinced that tofacitinib showed any significant benefit among patients. Initial studies were for patients who had already been on methotrexate therapy, which reduces inflammation and can slow disease progression. Tofacitinib appeared to provide little advantage among these patients, in terms of progression. The latest batch of data, however, covers patients who have not been on methotrexate therapy. Pfizer said during its July earnings call that the results among this set of patients demonstrates a clear benefit.