Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis. This post-hoc pooled analysis assessed commonalities and differences in tofacitinib efficacy and safety for US versus rest of the world (ROW) populations.
Pooled phase (P) III data from patients receiving tofacitinib 5 or 10 mg twice daily (BID) or placebo were assessed for efficacy at Month 3 and for safety outcomes over 12 months. For adverse events of special interest, data on tofacitinib 5 or 10 mg BID or placebo were pooled from six PII and five PIII randomised studies.
PIII data were available for 664 vs. 2447 and PII/PIII data for 943 vs. 3567 US vs. ROW patients, respectively. The US population had a higher proportion of Caucasians (81.5% vs. 54.4%), lower proportion of Asians (1.0% vs. 34.6%), and higher mean body weight (85.7 vs. 66.2 kg) and body mass index (31.5 vs. 25.6 kg/m2) compared with ROW. At Month 3, PIII efficacy was similar between US and ROW as assessed by ACR 20/50/70 response rates, remission rates (DAS 28-4[ESR]<2.6), and HAQ-DI scores. Diarrhoea, peripheral oedema, and upper respiratory tract infection occurred in >5% of PIII patients in the US population. Incidence rates for adverse events of special interest were similar between the US and ROW PII/PIII populations.
Patients in the US achieved similar efficacy and safety with tofacitinib 5 and 10 mg BID compared with patients in ROW.