Channeling effects in the prescription of new therapies: the case of emicizumab for hemophilia A

Arash Mahajerin*, Imi Faghmous, Peter Kuebler, Monet Howard, Tao Xu, Carlos Flores, Tiffany Chang, Francis Nissen

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

1 Citation (Web of Science)


Aim: To determine if emicizumab was channeled to clinically complex people with hemophilia A upon approval. Methods: Claims data (16 November 2017, through 31 December 2019) from US-based insurance databases were analyzed to compare the clinical complexity of people with hemophilia A initiating emicizumab with matched individuals receiving factor VIII (FVIII) episodically or prophylactically. People with hemophilia A with evidence of previous bypassing agent use (indicating FVIII inhibitors) were excluded. Outcomes included bleeding events, arthropathy, pain, comorbidities and healthcare costs. Results: A larger proportion of emicizumab users had bleeding events, comorbidities and arthropathy and greater healthcare costs in the year prior to starting emicizumab compared with FVIII users. Conclusion: Claims-based data limitations prevent an absolute conclusion. Nevertheless, emicizumab users appear more clinically complex than FVIII users, suggesting post-approval channeling.

Original languageEnglish
Pages (from-to)717-728
Number of pages12
JournalJournal of Comparative Effectiveness Research
Issue number10
Early online date10 May 2022
Publication statusPublished - Jul 2022


  • channeling
  • claims data
  • coagulation factor VIII
  • comorbidity
  • emicizumab
  • healthcare systems
  • hemophilia A
  • pharmacovigilance
  • safety

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