Pfizer is celebrating the news that advisors to the US Food and Drug Administration have recommended approval of tofacitinib, its oral Janus kinase (JAK) inhibitor for rheumatoid arthritis.

The FDA's Arthritis Advisory Committee has voted 8-2 that the drug should get the green light as a treatment of adults with moderately to severely active RA who have had an inadequate response to another disease-modifying anti-rheumatic drug (DMARD). If approved, and tofacitinib has a Prescription Drug User Fee Act action date in August 2012, it would be the first new oral DMARD for RA in more than 10 years and the first JAK inhibitor to get the thumbs-up for the disease.

Pfizer notes that tofacitinib has been evaluated in 4,800 patients in a development programme that included five Phase III trials and two ongoing long-term extension studies. It is also under review in Europe and Japan.

The recommendation follows documents published by FDA staffers earlier in the week which expressed concerns that tofacitinib increased risks of serious infections and malignancies, as well as higher chance of lymphoma. Specifically, some panellists were worried about over-immunosuppression with the higher dose (Pfizer is looking for approval at 5mg and 10mg dose).

Nevertheless, it looks as though tofacitinib will be available to patients  who do not respond to injectable tumour necrosis factor (TNF) inhibitors, notably Humira (adalimumab; Abbott), Enbrel (etanercept; Amgen/Pfizer) and  Remicade (infliximab; Johnson & Johnson/Merck & Co). That subset of patients amount to about a third of RA sufferers.