Two Phase 3 Trials Show Tofacitinib Effectively Treats PsA Regardless of Methotrexate Background Dose

According to a post-hoc exploratory analysis, the efficacy of tofacitinib was generally greater than the placebo after 3 months of treating psoriatic arthritis (PsA) with the background doses of methotrexate making no noticeable difference.

Although methotrexate is often used to treat psoriatic arthritis, the data available on the impact of varying background methotrexate doses with the efficacy and safety of Janus kinase inhibitors is limited. Therefore, the authors sought to determine if background methotrexate would affect the efficacy and safety of tofacitinib.

The data studied by researchers that led to these results were pooled from two phase 3, double- blind trials made up of 556 patients. The patients received either tofacitinib 5 mg twice per day BID (n=186 patients), 10 mg twice per day (n=178), or placebo (n=192), and patients also received stable methotrexate (≤15mg/week, n=371; >15mg/week, n=185). Therapy efficacy as determined by various scales (eg, American College of Rheumatology score, Leeds Enthesitis Index, Dactylitis Severity Score) was stratified by methotrexate dose after 3 months.

The assessment showed that methotrexate has no real effect on how well tofacitinib works on patients with PsA. Overall, tofacitinib had greater efficacy than placebo. The 5 mg dose had greater improvements in efficacy outcomes with a methotrexate dose greater than 15 mg, whereas patients receiving the 10 mg dose of tofacitinib had better outcomes with a methotrexate dose 15 mg or less.

However, headaches were associated with methotrexate doses great than 15 mg per week and decreased hemoglobin levels were observed in patients receiving tofacitinib 10 mg and methotrexate 15 mg or less.

Data from this trial should still be interpreted with caution due to the small sample sizes, but “the safety profile was generally consistent between groups,” wrote the study authors.

Reference
Kivitz AJ, FitzGerald O, Nash P, et al. Efficacy and safety of tofacitinib by background methotrexate dose in psoriatic arthritis: post hoc exploratory analysis from two phase III trials. Clin Rheumatol. Published online September 12, 2021. doi:10.1007/s10067-021-05894-2