Abatacept for lupus nephritis: Alternative definitions of complete response support conflicting conclusions
Wofsy D, Hillson JL, Diamond B; Arthritis & Rheumatism (Jul 2012)
Source: Arthritis Rheum
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OBJECTIVE: Recent lupus nephritis trials have all used different criteria to assess complete response (CR). The objective of this analysis was to compare several previously proposed criteria using the same data set from a large trial of abatacept in lupus nephritis (IM101075). By so doing, we sought: (i) to determine which criteria are most sensitive to differences among treatment groups; and (ii) to further examine the potential of abatacept in lupus nephritis.
METHODS: Subjects in BMS study number IM101075 received either abatacept or placebo on a background of mycophenolate mofetil and corticosteroids. Using data from this trial, we assessed CR rates at 12 months according to five sets of criteria from: (1) the trial protocol; (2) the ALMS trial of mycophenolate mofetil; (3) the LUNAR trial of rituximab; (4) an ongoing NIH trial of abatacept (ACCESS); and (5) published recommendations of the American College of Rheumatology.
RESULTS: The per-protocol CR definition showed no difference among groups. In contrast, the ALMS, LUNAR, and ACCESS definitions each showed significantly higher CR rates in both treatment groups relative to control. The largest differences were observed using the LUNAR criteria (CR rates of 6% among control subjects, compared to 22% and 24% in the two abatacept groups).
CONCLUSION: The choice of definition of complete response can determine whether a lupus nephritis trial is interpreted as a success or a failure. This analysis provides an evidence-based rationale for choosing among alternative definitions, and it offers a strong rationale for conducting further studies of abatacept in lupus nephritis.