Results of Amgen’s second and final period of the PRESERVE trial have been announced. PRESERVE is a two-period multi-center trial in individuals suffering from moderately active rheumatoid arthritis (RA). Participants in the trial achieved clinical remission on Enbrel® (etanercept) or methotrexate (MTX) combined or a Disease Activity Score (DAS) of 28 low disease activity (LDA) in period one. In period two participants were randomly assigned to continue ENBREL combined with MTX or MTX alone. Results from period two revealed that the ratio of participants who maintained low disease activity of achieved clinical remission at week 88 was considerably higher in participants who received Enbrel combined with MTX compared to patients who received MTX alone. Results from this trial have been accepted in the late-breaker poster presentation at the 2011 American College of Rheumatology Annual Scientific Meeting in Chicago, from November 5-9, 2011.

Although individuals with moderately active rheumatoid arthritis represent the largest RA population, they have not been largely investigated as a distinct group in prospective clinical investigations. The PRESERVE (A Prospective, Randomized Etanercept Study to Evaluate Reduced dose Etanercept combined with MTX versus full dose Etanercept combined with MTX versus MTX alone for effectiveness and radiographic endpoints in a moderate rheumatoid arthritis population) investigation is the largest completed clinical trial of a biologic therapy in adult individuals who suffer with moderately active rheumatoid arthritis, despite MTX treatment.

The study met its initial and conditional primary endpoints. It revealed that moderately active rheumatoid arthritis patients who received 50mg of Enbrel weekly combined with MTX, and patients who received 25mg of Enbrel weekly combined with MTX had a statistically greater response rate at week 88 compared with individuals who received only MTX.

After achieving low disease activity score ( [DAS] 28 ≤3.2) at week 36, the percentage of patients who received 50mg weekly of Enbrel plus MTX (primary endpoint) and those who received 25mg of Enbrel plus MTX (conditional primary endpoint) maintaining LDA at week 88 was considerably higher than patients who received only MTX (82.6%, 79.1% and 42.6% respectively [P

The safety profile from PRESEVE was the same as observed in prior Enbrel investigations – there were no new safety signals. During Period two 35 participants (5.8%) reported at least one serious side effect. 13 participants (6.4%) in the full dose group experienced at least one serious adverse effect, 7 participants (3.5%) in the reduced dose group, and 15 participants in the MTX-only group experienced at least one serious adverse effect. No specific serious adverse effect was observed in more than two participants. Two deaths occurred in the Enbrel 50mg weekly group although they were considered to be unrelated to the investigation medication.

Written by Grace Rattue