Cutaneous Lymphoma Associated with JAK Inhibitors: A Pharmacovigilance Analysis of the FAERS Database and Literature Review

The increasing use of JAK inhibitors in clinical practice is raising concerns regarding the potential risk of cutaneous lymphoma. This study aimed to conduct a comprehensive search for cases of cutaneous lymphoma associated with JAK inhibitors in the Food and Drug Administration's Adverse Event Reporting System. The clinical characteristics of cases from January 2004 to September 2023 were retrieved from the FAERS database. Disproportionality and Bayesian analyses were performed to detect signals for cutaneous lymphoma associated with JAK inhibitors. In total, 24 cases of cutaneous lymphoma were identified associated with JAK inhibitors, including tofacitinib, ruxolitinib, baricitinib, upadacitinib, and abrocitinib. The majority of patients (64%) were aged 60 or older, with no significant difference in incidence between genders. The average onset time was 8.64 months. One patient with ruxolitinib experienced a fatal outcome, and 1 patient with tofacitinib had a life-threatening event. Cutaneous lymphoma associated with baricitinib has the highest reporting odds ratio (23.91, 95% confidence interval 10.71-53.4), proportional reporting ratio (23.88, χ2 = 103.67), information component (4.57, IC025 = 2.05), and empirical Bayes geometric mean (23.73, EBGM05 = 12.12). The occurrence of cutaneous lymphoma associated with JAK inhibitors highlights the importance of pharmacovigilance studies to deepen our understanding of both the medications and associated conditions.