Treatment Patterns Among Adults with Primary Immune Thrombocytopenia Diagnosed in Hematology Clinics in the United States.

Patients with immune thrombocytopenia (ITP) have low platelet counts and an increased risk of bleeding. We described treatment patterns and clinical outcomes in routine practice in the United States (US). Using electronic health record data from hematology/oncology clinics linked to administrative claims in the US, we studied 447 adults newly diagnosed with primary ITP from 2011 to 2016. Patients with a secondary cause of thrombocytopenia were excluded. The incidence of ITP treatment initiation, bleeding events, and rescue therapy use were estimated using competing risk models. At 1-year post-ITP diagnosis, 50% of patients were prescribed an oral corticosteroid, with the majority being prescribed immediately following diagnosis. Of the more common second-line options, rituximab use was the most frequent (1-year cumulative incidence: 16% [95% confidence interval: 12, 19]), followed by romiplostim (9% [7, 12] and eltrombopag (5% [3, 8]). Use of these drugs was similar at 2 years post-diagnosis. At 6 months post-ITP treatment initiation, the cumulative incidence of bleeding was similar among eltrombopag and romiplostim initiators (17% [6, 33] and 19% [9, 31], respectively) and was slightly lower in rituximab users (12% [6, 20]). However, during this same timeframe, rituximab users had a higher incidence of rescue therapy use (48% [36, 58] versus 29% [14, 46] in eltrombopag and 26% [14, 39] in romiplostim users). Although splenectomy was rare, at 6 months post-surgery nearly 20% had experienced a bleed and nearly 20% had required rescue. This study describes the health trajectory of adults with ITP who are managed in hematology clinics in the US and could inform the design of non-interventional studies of comparative effectiveness among treatments.

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© 2020 McGrath et al.

Déclaration de conflit d'intérêts

KK and AS are employees of Amgen Inc and have stock ownership in Amgen Inc. LJM, DR, and MAB are employees and own equity in NoviSci, Inc. RAO was an employee at NoviSci, Inc. at the time the research was conducted. LJM reports grants from Amgen, Inc. MAB has had research support from Amgen and AstraZeneca, and has served as a scientific advisor/consultant to Amgen, Merck, TargetPharma, Genentech, AbbVie, and RxAnte. IA is a consultant to Amgen, Novartis, Genentech, Incyte, Bayer and an advisory board member of Celgene and Ipsen. IA reports personal fees from Amgen and Novartis. JW receives research funding from Incyte, Merck, Pfizer and Guardant, has stock ownership in Merck, Pfizer, Eli Lilly, Becton Dickinson, Abbott Labs, Biogen, and Allergan, and is a consultant to and reports personal fees from Amgen and Novartis. The authors report no other conflicts of interest in this work.