Exposure to non-corticosteroid treatments in adult primary immune thrombocytopenia before the chronic phase in the era of thrombopoietin receptor agonists in France. A nationwide population-based study

The objective of this study was to describe the exposure to non-corticosteroid treatments in adult primary immune thrombocytopenia (ITP) patients before the chronic phase at a nationwide level. Study population is derived from the 2009-2011 cohort of the French Adult Immune Thrombocytopenia: a French pHarmacoepidemiological study (FAITH, no. ENCEPP 4574). The FAITH cohort includes all incident and persistent or chronic adult primary ITP patients treated in France. It was built through the nationwide French health insurance database, called SNIIRAM. For the present study, we included FAITH patients who were followed by at least 12 months and who had at least one exposure to a non-corticosteroid treatment before the ITP chronic phase. Exposure to non-corticosteroid treatments was searched through in- and out-hospital dispensing. Predictors of the choice among first-line non-corticosteroid treatments (rituximab, splenectomy or other drugs) were studied using a multinomial regression. The study population included 443 patients. Non-corticosteroid treatments used in more than 10% of the patients at any time before the chronic phase were: rituximab (57.8%), splenectomy (22.1%), TPO-RAs (16.8%), repeated intravenous immunoglobulin (IVIg) courses (15.0%), danazol (14.4%) and dapsone (10.8%). Rituximab was the most used first-line non-corticosteroid treatment (45.4%). TPO-RAs and dapsone were more frequently used after 65 years of age (respectively, 24.8% versus 12.8%, p=0.01 and 17.6% versus 7.2%, p=0.0008), unlike splenectomy (16.4% versus 25.2%, p=0.03). Age over 65 years was the sole independent predictor of first-line non-corticosteroid treatment choice. In conclusion, rituximab was the leading non-corticosteroid treatment used before the chronic phase. TPO-RAs were mainly used in accordance with their labeling. IVIgs were consistently used as a chronic non-corticosteroid treatment.