Pfizer has reported positive findings from the 12-month Phase IIIb/IV ORAL Shift clinical trial of Xeljanz (tofacitinib), a JAK inhibitor, to treat moderately to severely active rheumatoid arthritis (RA) in adults.

During the 694-patient study, participants with low disease activity (LDA) in the extended release (XR) 11mg once daily (QD) Xeljanz plus methotrexate (MTX) arm after a 24-week open-label run-in period were again randomised.

The randomised subjects were assessed for the safety and efficacy of Xeljanz XR 11mg QD as monotherapy following MTX withdrawal compared to continued combination treatment.

Monotherapy of the drug showed non-inferiority of MTX withdrawal compared to the combination at week 48, as measured by the primary endpoint.

The primary endpoint was the change in the Disease Activity Score from week 24 to the end of the double-blind MTX withdrawal phase at week 48.

Pfizer Global Product Development Inflammation & Immunology chief development officer Michael Corbo said: “We are extremely pleased with the findings from ORAL Shift, which to date is the only non-inferiority study to evaluate and demonstrate the efficacy of a JAK inhibitor after methotrexate withdrawal in adults with moderately to severely active RA who achieved low disease activity after combination therapy.”

Safety analysis of the trial found nasopharyngitis, upper respiratory tract infection, and bronchitis as the most frequent adverse events (AEs) in the double-blind treatment period.

The AEs, serious AEs (SAEs) and discontinuations due to AEs rates were observed to be generally comparable between treatment groups.

In the monotherapy arm, AEs occurred in 40.5% of patients and there were ten SAEs and five discontinuations due to AEs, while the combination group had AEs in 41% of subjects with five SAEs and five discontinuations due to AEs.