Combination Advanced Therapy Exposures in Immune-Mediated Inflammatory Diseases Are Associated with Increased Infection Risk, Even with Short Median Duration

What To Know

A large US administrative-data cohort study examined overlapping (‘combination advanced therapy’, CAT) exposures to targeted synthetic or biologic DMARDs across immune-mediated inflammatory diseases (IMIDs). About 14% of patients initiating advanced therapies had at least one CAT episode; the median CAT duration was 42 days.

CAT person-time had a higher rate of serious infection and an adjusted hazard ratio of 1.20 (95% CI 1.08–1.33) for first serious infection compared with single advanced therapy.

What the study did: It used MarketScan claims data (2016–2023) to identify episodes of advanced therapy, defined CAT as ≥30 days overlap between advanced therapy classes, and adjusted for age, sex, IMID type, comorbidities, csDMARDs, and glucocorticoids.

Key limitations to This is an observational administrative-claims analysis, so treatment assignment is not randomized and residual confounding (indication, disease severity, infection risk) may remain. Claims definitions capture hospitalizations and IV antibiotics for “serious infection” but lack microbiologic detail and clinical adjudication.

Bottom line: Short-duration overlaps of biologic/targeted therapies occurred in routine care and were associated with a modestly increased adjusted risk of serious infection; patients, clinicians, and researchers should interpret the association cautiously given observational design and potential confounding.