Split vs single-dose oral methotrexate in rheumatoid arthritis: a randomized controlled trial (SMART study)

Pharmacokinetic evidence suggests split dose of oral methotrexate increases bioavailability, but unproven to improve efficacy. Thus, we planned to compare clinical response of split vs single-dose oral methotrexate in rheumatoid arthritis (RA).

This pragmatic, open-label (blinded assessor) randomized controlled trial was conducted across six university hospitals in India and enrolled patients with seropositive RA with active disease (TJC₂₈ ≥ 4 and SJC₂₈ ≥ 2). They were randomized 1:1 to split-dose (15 mg morning, 10 mg evening) or single-dose (25 mg) once weekly oral methotrexate for 16 weeks, after which a second DMARD could be added. Primary outcome and key secondary outcomes were EULAR good response at 24 weeks and 16 weeks respectively. Analysis was by intention-to-treat with non-response imputation. Clinical Trials Registry-India CTRI/2021/02/031361.

Two hundred fifty-three patients [83% female, mean age 42.2 years, mean disease duration 2.1 yrs] were randomized to receive either split-dose (n = 128) or single-dose (n = 125) methotrexate. Primary outcome, good response at 24 weeks, was not significantly higher with split-dose methotrexate (+ 6.5%, 95% CI - 4.2 to 17.2%, p = 0.263). However, key secondary outcome, good response at 16 weeks, was significantly higher with split-dose methotrexate (+ 12.3%, 95% CI 3.5 to 21.3%, p = 0.008). Also, less patients in split-dose group required addition of second DMARD at 16 weeks (- 19.5%, p = 0.003). Numerically higher transaminitis and intolerance occurred with split-dose MTX.

Although the primary outcome was not met, we found faster response and better efficacy at 16 weeks with split-dose oral MTX, and reduced need for a second DMARD. Key Points • This was the first RCT to compare split-dose (same-day, morning, evening) to single-dose oral methotrexate (MTX) and included 253 patients of RA. • Primary outcome was not met, i.e., split-dose MTX was not superior in terms of EULAR good response at 24 weeks. • However, key secondary outcome was met, i.e., split-dose MTX met led to significantly higher EULAR good response at 16 weeks; also it reduced need for addition of a second DMARD. • Split-dose MTX was associated with higher adverse effects (numerically) in terms of both intolerance and transaminitis.