Pfizer’s hope of expanding the use of its arthritis therapy Xeljanz into psoriasis has been knocked back after the FDA declined to approve its marketing application.
The US regulator sent Pfizer a Complete Response Letter (CRL) indicating that it would be unable to approve Xeljanz (tofacitinib) for psoriasis without additional information, thought to relate to the safety of the drug.
In a statement, Pfizer said it would work with the FDA to resolve the deficiencies in the dossier, and said this could include “providing additional safety analyses of Xeljanz for the proposed indication”.
The setback is a big disappointment for Pfizer as the psoriasis indication could have resulted in a sharp uptick in sales of Xeljanz, which have lagged behind expectations since it was first launched in 2012.
The roll-out of the drug has been hit by the FDA’s decision to approve only the 5mg twice-daily dose in rheumatoid arthritis (RA) on the grounds that a higher 10mg dose was not considered to have an adequate risk-to-benefit ratio. Meanwhile, Pfizer also failed to win approval for Xeljanz as an RA therapy in Europe, on concerns about the risk of infections with the drug.
Pfizer booked $224m in Xeljanz sales in the first six months of 2015, an 86% increase on the same period of 2014, but the product still has a long way to go to reach earlier predictions of $3bn a year in peak sales.
Psoriasis affects around seven million people in the US and Pfizer has been hoping for big things from Xeljanz in this area. Phase III data showed that the oral therapy was as effective as treatment with Pfizer’s own injectable Enbrel (etanercept), one of the TNF inhibitor class of drugs that are widely used in psoriasis.
Even if Pfizer can eventually convince the FDA of Xeljanz’ safety, the delay to the programme will allow other new psoriasis drugs to establish themselves on the market.
A particular threat could come from Novartis’ Cosentyx (secukinumab) which, while injectable, has been shown to be more effective than the TNF inhibitors in controlling skin lesions.
Meanwhile, Pfizer is also waiting for an FDA verdict on an application to add the treatment of moderate to severe RA in patients who have had an inadequate response or intolerance to methotrexate to the label for an 11mg once-daily formulation.