Use of tofacitinib for rheumatoid arthritis increases the risk of developing cancer by almost 50% compared with therapy with a TNF inhibitor, according to a US safety analysis.

The findings have already prompted the Food and Drug Administration to add a ‘black box’ warning on tofacitinib, as well as two other Janus kinase (JAK) inhibitors.

The Pfizer-funded post-authorisation trial was mandated after clinicians noted users had increased serum lipid levels and seemed more prone to cancers, including lymphoma.

Researchers stressed, however, that the disease-modifying antirheumatic drug (DMARD) still had an important role to play in patients with a strong preference for oral medications.