Objective: T cells play a key role in the pathogenesis of early systemic sclerosis. This study was undertaken to assess the safety and efficacy of abatacept in patients with diffuse cutaneous systemic sclerosis (dcSSc). Methods: In this 12-month, randomized, double-blind, placebo-controlled trial, participants were randomized 1:1 to receive either subcutaneous abatacept 125 mg or matching placebo, stratified by duration of dcSSc. Escape therapy was allowed at 6 months for worsening disease. The coprimary end points were change in the modified Rodnan skin thickness score (MRSS) compared to baseline and safety over 12 months. Differences in longitudinal outcomes were assessed according to treatment using linear mixed models, with outcomes censored after initiation of escape therapy. Skin tissue obtained from participants at baseline was classified into intrinsic gene expression subsets. Results: Among 88 participants, the adjusted mean change in the MRSS at 12 months was −6.24 units for those receiving abatacept and −4.49 units for those receiving placebo, with an adjusted mean treatment difference of −1.75 units (P = 0.28). Outcomes for 2 secondary measures (Health Assessment Questionnaire disability index and a composite measure) were clinically and statistically significantly better with abatacept. The proportion of subjects in whom escape therapy was needed was higher in the placebo group relative to the abatacept group (36% versus 16%). In the inflammatory and normal-like skin gene expression subsets, decline in the MRSS over 12 months was clinically and significantly greater in the abatacept group versus the placebo group (P < 0.001 and P = 0.03, respectively). In the abatacept group, adverse events occurred in 35 participants versus 40 participants in the placebo group, including 2 deaths and 1 death, respectively. Conclusion: In this phase II trial, abatacept was well-tolerated, but change in the MRSS was not statistically significant. Secondary outcome measures, including gene expression subsets, showed evidence in support of abatacept. These data should be confirmed in a phase III trial.
Bibliographical noteFunding Information:
This was an investigator‐initiated trial designed by Dinesh Khanna, MD, MSc, and the Steering Committee. The industry funder, Bristol‐Myers Squibb, had no role in collecting, analyzing, and interpreting the data. Mechanistic studies, including analysis of gene expression in skin biopsies, was funded by the NIH/National Institute of Allergy and Infectious Diseases (NIAID) through the University of Michigan Clinical Autoimmunity Center of Excellence. The data were stored at the University of Michigan. The manuscript was drafted by Drs. Khanna and Spino with input from other coauthors and was reviewed by Bristol‐Myers Squibb and NIH/NIAID before final submission. No medical writer was involved in the creation of the manuscript. Publication of this article was not contingent upon approval by Bristol‐Myers Squibb.
We wish to thank the participants, study coordinators, statistical analysts (Haoyan Zhong and Richard McLain), and the Data Safety Monitoring Board (Donald Tashkin, MD, Chair, University of California at Los Angeles; Thomas Medsger, Jr., MD, University of Pittsburgh, Pittsburgh, Pennsylvania; and Robert Parker, ScD: Massachusetts General Hospital, Boston).
© 2019, American College of Rheumatology
PubMed: MeSH publication types
- Clinical Trial, Phase II
- Journal Article
- Multicenter Study
- Randomized Controlled Trial
- Research Support, N.I.H., Extramural
- Research Support, Non-U.S. Gov't