Regardless of the methotrexate dose, the efficacy of tofacitinib was numerically greater than placebo in adult patients with active psoriatic arthritis.

A study explored the potential influence of background methotrexate dose (≤ 15 or >15 mg per week) on safety and effectiveness of tofacitinib (an oral Janus kinase inhibitor) for the management of psoriatic arthritis.

This study pooled data from two phase 3, double-blind clinical studies (OPAL Beyond, OPAL Broaden) and recruited people receiving tofacitinib (five or ten mg twice daily [BID]), or placebo, with stable methotrexate.

In this post hoc exploratory analysis, the efficacy endpoints at third month stratified by methotrexate dosage were: (i) Health Assessment Questionnaire-Disability Index (HAQ-DI), (ii) Physician's global assessment of psoriatic arthritis (PGA-psoriatic arthritis-visual analog scale [VAS]), (iii) American College of Rheumatology (ACR)20/50/70, (iv) Dactylitis Severity Score (DSS), (v) alteration from baseline in HAQ-DI, (vi) Leeds Enthesitis Index (LEI), (vii) Psoriasis Area and Severity Index (PASI) 50/75; and (viii) patient's global joint and skin assessment (PGJS-VAS). Laboratory parameters and noxious events were the safety assessments incorporated.

556 participants received tofacitinib 5 mg BID (n = 186), 10 mg BID (n = 178), or placebo (n = 192), plus methotrexate (371 received ≤15 mg per week, 185 received >15 mg per week). Tofacitinib showed higher effectiveness compared to placebo in the third month. People treated with 5 mg BID tofacitinib displayed greater numerical improvements in efficacy endpoints at third month with methotrexate > 15 mg per week vs methotrexate ≤ 15 mg per week.

On the other hand, people treated with 10 mg BID tofacitinib showed the opposite. The safety profile showed consistency between the study groups. Headache was a common noxious event linked with the higher methotrexate dose (> 15 mg per week). Reduced hemoglobin levels were noted in people treated with tofacitinib 10 mg BID and background methotrexate ≤ 15 mg per week.

For the majority of dermatologic and rheumatologic outcomes evaluated, 5 mg tofacitinib BID, in combination with a greater dose of background methotrexate, was more effective than a lower dose of background methotrexate. However, the opposite was noted for people treated with 10 mg tofacitinib BID.