Daily treatment with tofacitinib (Xeljanz) led to more malignancies and adverse cardiovascular events in older rheumatoid arthritis patients compared with treatment with a tumor necrosis factor (TNF) inhibitor, according to the partial results of a safety study announced last week by Pfizer.
The postmarketing study known as ORAL Surveillance began in 2014 to evaluate the safety of the Janus kinase (JAK) inhibitor tofacitinib compared to a TNF inhibitor in RA patients 50 years of age or older with at least one additional cardiovascular risk factor. Its 4,362 participants were randomized to either daily doses of 5 mg (n = 1,455) or 10 mg (n = 1,456) of tofacitinib or the TNFi (n = 1,451), which was adalimumab for patients in the United States, Canada, and Puerto Rico, and etanercept elsewhere. During analysis, adverse events were pooled for all patients on tofacitinib.
Overall, 135 patients developed major adverse cardiovascular events (MACE) and 164 developed malignancies – excluding nonmelanoma skin cancer. The incidence of adjudicated malignancies was significantly higher in the tofacitinib group, compared with the TNFi group (1.13 vs. 0.77 per 100 person-years; hazard ratio, 1.48; 95% confidence interval, 1.04-2.09). The rate of MACE was also higher in the combined tofacitinib group (0.98 vs. 0.73 per 100 person-years; HR, 1.33; 95% CI, 0.91-1.94). Both rates for tofacitinib did not meet the trial’s noninferiority criteria.
Among the patients on tofacitinib, the most reported MACE was myocardial infarction and the most reported malignancy was lung cancer. Study participants with noted risk factors – including older age and smoking – were more likely to experience adverse events.
In February 2019, patients in the 10-mg tofacitinib group were switched to the 5-mg because of a safety signal indicating increased risk of pulmonary embolism and death.
Tofacitinib was approved for RA in November 2012, though concerns about serious side effects had been noted during clinical trials and a boxed warning was ultimately added to the drug’s label. Tofacitinib is also approved for adults with active psoriatic arthritis, adults with moderately to severely active ulcerative colitis, and patients aged 2 years or older with active polyarticular course juvenile idiopathic arthritis. Other JAK inhibitors such as baricitinib and upadacitinib have been approved for RA in the interim as well, though the higher dose of baricitinib was rejected in committee because of safety concerns and both their boxes also warn against infections, thrombosis, and cancer.
A postmarketing safety study on baricitinib is expected to be completed in 2025.
The full results of the ORAL Surveillance study – which should address safety regarding pulmonary embolism and mortality, as well as efficacy data – have not yet been released. “Pfizer is working with the [FDA] and other regulatory agencies to review the full results and analyses as they become available,” the press release said.