Objective: To provide context for the malignancy experience in the rheumatoid arthritis (RA) abatacept clinical development program (CDP) by performing comparisons with similar RA patients and the general population.
Methods: Malignancy outcomes included total malignancy (excluding non-melanoma skin cancer (NMSC)), breast, colorectal, lung cancers, and lymphoma. Comparisons were made between the observed incidence in patients within the abatacept CDP and RA patients on disease-modifying anti-rheumatic drugs (DMARDs) identified from 5 data sources: the population-based British Columbia RA Cohort, the Norfolk Arthritis Register, the National Data Bank for Rheumatic Diseases, the Sweden Early RA Register, and the General Practice Research Database. Age- and sex-adjusted incidence rates (IRs) and standardized incidence ratios (SIRs) were used to compare events in the abatacept trials to the RA DMARD cohorts and the general population.
Results: A total of 4,134 RA patients treated with abatacept in 7 trials and 41,529 DMARD-treated RA patients in the 5 observational cohorts were identified for study inclusion. In the abatacept-treated patients, the 51 malignancies (excluding NMSC), 7 cases of breast, 2 cases of colorectal, 13 cases of lung cancer, and 5 cases of lymphoma observed were not greater than the range of expected cases from the 5 RA cohorts. The SIRs comparing RA patients to the general population were consistent with those reported in the literature.
Conclusions: The IRs of total malignancy (excluding NMSC), breast, colorectal, lung cancers, and lymphoma in the abatacept CDP were consistent with those in a comparable RA population. These data suggest no new safety signals with respect to malignancies, which will continue to be monitored.