Combotherapies in immune-mediated inflammatory diseases: A study using the Clinical Data Warehouse from Paris Hospitals’ Public Assistance

BACKGROUND: The combination of different biological and targeted synthetic DMARDs (i.e., combotherapy) has recently emerged in the management of immune-mediated inflammatory diseases (IMID). However, real-life data across specialities and prognostic factors related to combotherapy are lacking. METHODS: Multicenter observational study conducted using the Clinical Data Warehouse from Paris Hospitals' Public Assistance including IMID patients under combotherapy, and a matched monotherapy control group. The primary endpoint was the occurrence of serious adverse events (SAE), defined by severe infections, major cardiovascular events, neoplasia and mortality (all-cause). RESULTS: From 42,071 subjects having an IMID, 131 combotherapy lines were identified among 125 patients (median age of 36 years, 58 % females) between 2017 and 2022. The most frequent IMIDs were inflammatory bowel disease (48.8 %), connective tissue diseases (23.2 %), inflammatory myopathies (14.4 %) and vasculitis (11.2 %). After a median follow-up of 15 months [IQR 19], 30 (24 %) patients presented severe infections, 5 (4 %) neoplasia, 4 (3.2 %) venous thromboembolism, 3 (2.4 %) acute coronary syndromes and 7 (5.6 %) deaths. The 1-year cumulative incidence of SAE and severe infections were 29 % (95 %CI 21-38), and 24 % (95 %CI 16-32), respectively. The survival, incidence of SAE and severe infections were not statistically different from combotherapy patients compared to monotherapy controls (n=251) after adjustment for confounders. In multivariate analyses, we found abatacept + JAKi (HR 6.81, 95 %CI 1.88-24.68), anti-IL-1-based (HR 4.82, 95 %CI 1.17-19.89) and anti-CD20-based (HR 4.03, 95 %CI 1.22-13.31) combotherapies to be independently associated with an increased risk of SAE. CONCLUSION: The overall risk of SAE under combotherapy does not seem greatly increased compared to monotherapy, but certain combinations warrant caution. The combotherapy composition seems predictive of safety outcomes.