The trajectory of clinical responses in patients with early rheumatoid arthritis who achieve sustained remission in response to abatacept: subanalysis of AVERT-2, a randomized phase IIIb study

BACKGROUND: AVERT-2 (a phase IIIb, two-stage study) evaluated abatacept + methotrexate versus methotrexate alone, in methotrexate-naive, anti-citrullinated protein antibody-positive patients with early (≤ 6 months), active RA. This subanalysis investigated whether individual patients who achieved the week 24 Simplified Disease Activity Index (SDAI) remission primary endpoint could sustain remission to 1 year and then maintain it following changes in therapy. METHODS: During the 56-week induction period (IP), patients were randomized to weekly subcutaneous abatacept 125 mg + methotrexate or abatacept placebo + methotrexate. Patients completing the IP who achieved SDAI remission (≤ 3.3) at weeks 40 and 52 entered a 48-week de-escalation (DE) period. Patients treated with abatacept + methotrexate were re-randomized to continue weekly abatacept + methotrexate, or de-escalate and then withdraw abatacept (after 24 weeks), or receive abatacept monotherapy. Proportions of patients achieving sustained SDAI and Boolean remission, and Disease Activity Score in 28 joints using C-reactive protein (DAS28 [CRP]) < 2.6, were assessed. For patients achieving early sustained SDAI remission at weeks 24/40/52, flow between disease activity categories and individual trajectories was evaluated; flow was also evaluated for later remitters (weeks 40/52 but not week 24). RESULTS: Among patients treated with abatacept + methotrexate (n/N = 451/752) at IP week 24, 22% achieved SDAI remission, 17% achieved Boolean remission, and 42% achieved DAS28 (CRP) < 2.6; of these, 56%, 58%, and 74%, respectively, sustained a response throughout IP weeks 40/52. Among patients with a sustained response at IP weeks 24/40/52, 82% (14/17) on weekly abatacept + methotrexate, 81% (13/16) on abatacept monotherapy, 63% (12/19) who de-escalated/withdrew abatacept, and 65% (11/17) on abatacept placebo + methotrexate were in SDAI remission at end of the DE period; rates were higher than for later remitters in all arms except abatacept placebo + methotrexate. CONCLUSIONS: A high proportion of individual patients achieving clinical endpoints at IP week 24 with abatacept + methotrexate sustained their responses through week 52. Of patients achieving early and sustained SDAI remission through 52 weeks, numerically more maintained remission during the DE period if weekly abatacept treatment continued. TRIAL REGISTRATION: NCT02504268 (ClinicalTrials.gov), registered July 21, 2015.