Tofacitinib may benefit Psoriatic Arthritis patients as monotherapy: LANCET study

The authors carried out an OPAL Balance study which is classified as an open-label, long-term extension study of tofacitinib in patients with psoriatic arthritis who participated in the OPAL Broaden and OPAL Beyond phase 3 studies. This 12-month, randomised, double-blind, placebo-controlled, methotrexate withdrawal substudy (50 centres, 14 countries) included patients from OPAL Balance who completed tofacitinib treatment for 24 months or more (≥3 months' stable tofacitinib 5 mg twice daily) and were receiving methotrexate (7·5–20 mg/week).

In this study, the patients were blindly randomised (1:1) using interactive response technology and received open-label tofacitinib 5 mg twice daily with either placebo (tofacitinib 5 mg twice daily plus placebo group) or continued methotrexate (tofacitinib 5 mg twice daily plus methotrexate group). Patients were masked to placebo or methotrexate, with identical capsules used.

Researchers defined the coprimary endpoints as the changes from substudy baseline in psoriatic arthritis disease activity score (PASDAS) and health assessment questionnaire-disability index (HAQ-DI) at month 6 in all randomised patients with one or more substudy drug dose. Safety was assessed throughout. No specific statistical hypothesis (either superiority or non-inferiority) was tested.

The following findings were highlighted-

a. At month 6, least squares mean (LSM) changes in PASDAS were 0·23 (SE 0·08) for tofacitinib 5 mg twice daily plus placebo and 0·14 (0·08) for tofacitinib 5 mg twice daily plus methotrexate (treatment difference LSM 0·09 [95% CI –0·13 to 0·31]), and changes in HAQ-DI were 0·04 (0·03) and 0·02 (0·03), respectively (treatment difference 0·03 [–0·05 to 0·10]).

b. Rates of adverse events, discontinuations because of adverse events, adverse events of special interest, and laboratory changes were generally similar between treatment groups, although liver enzyme elevations were more common with tofacitinib 5 mg twice daily plus methotrexate than tofacitinib 5 mg twice daily plus placebo.

c. Flares of worsening symptoms was reported in one (1%) of 90 patients in the tofacitinib 5 mg twice daily plus placebo group (recorded as psoriatic arthropathy).

Therefore, the investigators concluded that "some patients with psoriatic arthritis who are stable on tofacitinib 5 mg twice daily with background methotrexate might be able to discontinue methotrexate without clinically meaningful changes in disease activity and safety."