Tofacitinib is a drug of the janus kinase inhibitor class used for rheumatoid arthritis (RA) treatment. This is an post hoc analysis which estimated the effect of methotrexate (MTX) dose on the efficacy of tofacitinib in patients suffering from RA.

This ORAL Scan (NCT00847613) was a 2-year, randomized, Phase 3 trial investigating tofacitinib in MTX-inadequate responder (IR) patients with RA.

The patients were given tofacitinib 5 or 10 mg twice daily (BID), or placebo, with low (≤12.5 mg/week), moderate (>12.5 to <17.5 mg/week), or high (≥17.5 mg/week) firm background MTX.

At months 3 and 6, the efficacy endpoints encompassed  American College of Rheumatology (ACR) 20/50/70 response rates, and mean change from baseline in Clinical Disease Activity Index (CDAI), Disease Activity Score in 28 joints (DAS28)–4(erythrocyte sedimentation rate [ESR]), Health Assessment Questionnaire-Disability Index (HAQ-DI), and altered Total Sharp score.

A total of 797 patients were included in this analysis with tofacitinib 5 mg BID (N = 321), tofacitinib 10 mg BID (N = 316), or placebo (N = 160). Low MTX doses were given to 242 patients, moderate MTX doses to 333 patients and high MTX doses to 222 patients.

Across all MTX doses, ACR20/50/70 response rates were greater for both tofacitinib doses vs placebo at months 3 and 6. The mean changes from baseline in CDAI and HAQ-DI were notably greater for both tofacitinib doses vs placebo, irrespective of MTX category at month 3. Stablity was observed in imrovements at month 6.

Across MTX doses at month 6, both the tofacitinib doses revealed improvements in DAS28–4(ESR) and less structural progression vs placebo.

Hence, regardless of MTX dose, tofacitinib plus MTX portrayed greater clinical and radiographic efficacy than placebo in MTX-IR patients with RA.