Objectives: To evaluate the risk of serious infection (SI) and herpes zoster (HZ) in rheumatoid arthritis patients receiving JAK inhibitors.
Methods: We conducted a systematic literature review and meta-analysis of phase II and III randomized controlled trials of tofacitinib (5 mg bid), baricitinib (4 mg od) and upadacitinib (15 mg od). Patient-exposure years were calculated. A per-protocol analysis was applied, incorporating follow-up time from patients randomized to placebo who cross into the treatment arm. Pooled incidence rates per 100 person-years of SI and HZ were calculated. Incidence rate ratios (IRRs) of drug vs placebo were compared using a meta-synthesis approach.
Results: Twenty-one studies were included in the meta-analysis; 11 tofacitinib (5888 patients), six baricitinib (3520 patients) and four upadacitinib studies (1736 patients). For SI, the incidence rates were 1.97 (95% CI: 1.41, 2.68), 3.16 (95% CI: 2.07, 4.63) and 3.02 (95% CI: 0.98, 7.04), respectively. The IRRs comparing treatment arm to placebo were statistically non-significant: 1.22 (95% CI: 0.60, 2.45), 0.80 (95% CI: 0.46, 1.38) and 1.14 (95% CI: 0.24, 5.43), respectively. For HZ, the incidence rates were 2.51 (95% CI: 1.87, 3.30), 3.16 (95% CI: 2.07, 4.63) and 2.41 (95% CI: 0.66, 6.18), respectively. The IRR of HZ comparing baricitinib with placebo was 2.86 (95% CI: 1.26, 6.50). Non-significant IRRs were seen with tofacitinib and upadacitinib: 1.38 (95% CI: 0.66, 2.88) and 0.78 (95% CI: 0.19, 3.22), respectively. Indicator opportunistic infections excluding HZ were too rare to provide meaningful incidence rates.
Conclusion: The absolute SI rates were low. However across the JAK inhibitors, the incidence of HZ is higher than expected for the population (3.23 per 100 patient-years). While the risk was numerically greatest with baricitinib, indirect comparisons between the drugs did not demonstrate any significant difference in risk.
Systematic review registration number: Prospero 2017 CRD4201707879.
Keywords: immunosuppressants; meta-analysis; rheumatoid arthritis; systematic review; viruses.
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