Short-term risk of certain cancers similar in RA, PsA patients treated with JAK, TNF inhibitors

For patients with rheumatoid arthritis (RA) or psoriatic arthritis (PsA), initiation of Janus kinase (JAK) inhibitor treatment does not carry a higher short-term risk of cancer, with the exception of nonmelanoma skin cancer (NMSC), as compared with initiation of biological disease-modifying antirheumatic drugs (bDMARDs) including tumour necrosis factor (TNF) inhibitors, according to a study.

Data from the Swedish Rheumatology Quality Register, which were linked to other registers including the Cancer Register, were used for the study. The analysis included a total of 10,447 patients with RA and 4,443 patients with PsA who were initiated on JAK inhibitors, TNF inhibitors, or non-TNF bDMARDs.

In the RA cohort, cancers other than NMSC occurred in 38 patients in the JAK inhibitor group, 141 in the non-TNF group, and 213 in the TNF inhibitor group over a median follow-up of 1.95, 2.83, and 2.49 years, respectively. Multivariable Cox analysis showed no overall increased risk (hazard ratio [HR], 0.94, 95 percent confidence interval [CI], 0.65–1.38).

Meanwhile, NMSC occurred in 59 patients in the JAK inhibitor group, 126 in the non-TNF group, and 189 in the TNF inhibitor group. A risk increase was identified for JAK vs TNF inhibitors (HR, 1.12, 95 percent CI, 0.70–1.78) during the first year since treatment start and (HR, 2.12, 95 percent CI, 1.15–3.89) after two or more years after initiation.

In the PsA cohort, based on 5 vs 73 incident cancers other than NMSC, and 8 vs 73 incident NMSC, the corresponding HRs were 1.9 (95 percent CI, 0.7–5.2) and 2.1 (95 percent CI, 0.8–5.3) with JAK vs TNF inhibitors.

The findings suggest that while individuals initiating treatment with JAKi are not at higher short-term risk of cancers relative to those initiating treatment with TNFi, there is a substantially increased risk for NMSC.