Safety of the JAK and TNF inhibitors in rheumatoid arthritis: real world data from the Hong Kong Biologics Registry.

Objectives: To compare the incidence of major adverse cardiovascular events (MACEs), cancer and infective complications in RA patients using Janus kinase (JAKis) and TNF (TNFis) inhibitors.

Method: A retrospective analysis of data from the Hong Kong Biologics Registry 2008-2021 was performed. RA patients who had ever used JAKis or TNFis were included. The incidence of MACEs, cancer and infections were compared between the two groups, with adjustment for confounding factors.

Results: A total of 2471 courses of JAKis (n = 551) and TNFis (n = 1920) were used in 1732 RA patients (83.7% women, age 53.8 [12.5] years; follow-up 6431 patient-years). JAKi users had significantly older age, more atherosclerotic risk factors and higher frequency of past malignancies. A total of 15 and 40 MACEs developed in the JAKi and TNFi users, respectively (incidence 1.34 vs 0.75 per 100 patient-years; P = 0.22). There was no significant difference in the incidence of cancers between the two groups (0.81 [JAKi] vs 0.85 [TNFi] per 100 patient-years; P = 0.25). The adjusted hazard ratios of MACE and cancer in the JAKi users were 1.36 (95% CI: 0.62, 2.96) (P = 0.44) and 0.87 (95% CI: 0.39, 1.95) (P = 0.74), respectively. Rates of infections were significantly higher in the JAKi than TNFi users (16.3 vs 9.9 per 100 patient-years; P = 0.02), particularly herpes zoster (3.49 vs 0.94 per 100 patient-years; P < 0.001).

Conclusions: In a real-life setting, there is no increase in MACEs or cancers in users of JAKis compared with TNFis. However, the incidence of non-serious infections, including herpes zoster, was increased in users of JAKis.