Clin Exp Rheumatol 2017;35:614–22Because non-melanoma skin cancer (NMSC) is one of the most common malignancies associated with RA immunomodulatory therapies, this analysis looked to determine the rate of NMSC incidence per 100 patient-years in patients with RA receiving TOF in the clinical trial programme. The Phase 1, 2, and 3 IRs (combined) for both TOF 5- and 10 mg were low and comparable to those of adalimumab, MTX and placebo, IRs remained stable over time. TOF doses used in the 2 Phase 1; 8 Phase 2; and 6 Phase 3 studies ranged from 1, 3, 5, 10, 15 and 30 mg BID (and 20 mg QD), as monotherapy or with csDMARDS, mainly MTX. Patients who enroled into the 2 long-term extension studies (LTEs) received treatment with 5- or 10 mg BID. The following datasets were analysed: P123LTE, P123, P3, global LTE and Japan LTE. IRs were also analysed by sex, ethnicity, age and prior TNFi therapy use.In total, 83 of the 6092 patients included (3.6%) had NMSC events across 15 103 patient years. Patients with prior TNFi exposure had significantly higher NMSC IR compared with those who were naïve. Other risk factors included being Caucasian, male and ≥65 years of age. Of the twice-daily tofacitinib doses, 10 mg had higher NMSC IR than 5 mg in the LTE studies. However, this was a numerical and not a significant difference; meaning longer-term surveillance is necessary to confirm these results.