Characteristics associated with biosimilar use in Medicare recipients

Biosimilars/Research | Posted 16/04/2021 post-comment0 Post your comment

What patient, physician and practice characteristics are associated with biosimilar usage for the biologicals filgrastim and infliximab was a question asked by researchers from the US [1].

Patient MD002316 V13C05

Spending on biologicals in the US increased by 50.1% between 2014 and 2018, putting additional financial pressure on public and private payers. However, despite these increases, and the potential for lower cost biosimilars to alleviate some of this burden, products have been slow to launch in the US. To date (1 April 2021) 29 biosimilars plus four follow-on biologicals have been approved in the US [2]. However, of the 29 biosimilars approved, only 18 have so far been launched [3]. This compares with 73 approvals in Europe [4], almost all of which have been launched.

Author Emma Boswell Dean and colleagues carried out a cross-sectional study of Medicare* fee-for-service beneficiaries in order to study the association between biosimilar use and various characteristics. They included 40,656 patients who received a filgrastim product or an infliximab product between the launch of the first biosimilar (quarter 3 of 2015 for filgrastim-sndz and quarter 4 of 2016 for infliximab-dyyb) and December 2018.

The results showed that no patient demographic characteristics were associated with biosimilar use. Whereas two out of nine clinical indications (22.2%) were associated with biosimilar use: filgrastim use for neutropenia and infliximab use for Crohn’s disease. Several physician characteristics were associated with use of biosimilars, including high filgrastim or infliximab prescribing volume and specialty, e.g. haematologist-oncologists compared to primary care. Numerous practice characteristics were associated with biosimilar use, including practice setting (outpatient hospital department versus office practice) and hospital outpatient department ownership status (for-profit versus not-for-profit).

The authors noted that this study demonstrates that ‘adoption of biosimilars in Medicare has been uneven across different products’. The uptake of filgrastim-sndz has risen consistently over time, reaching 52% of the market by December 2018. However, the uptake of infliximab biosimilars has been significantly slower, reaching 10% of the market by December 2018. This pattern, according to the authors, ‘is consistent with the European experience, where infliximab uptake was significantly slower than filgrastim’. However, they point out that this ‘represents a lost opportunity for cost savings’.

The authors concluded that ‘practice setting and hospital ownership status had the largest associations with biosimilar usage’. This, according to the authors, suggests that ‘practices play a role in steering physicians toward certain medications’ and that ‘the types of practices with high biosimilar use differed by drug class’. They also found that ‘surprisingly, the direction of the associations between practice setting and uptake was opposite for the two biosimilars’. Finally, they added that ‘further research is needed to understand the reasons underlying differences in biosimilar uptake across practice settings for the filgrastim and infliximab drug classes’.

*Medicare is a national social insurance program, administered by the US federal government since 1966. It provides health insurance for Americans aged 65 and older who have worked and paid into the system. It also provides health insurance to younger people with disabilities.

Conflict of interest
The authors of the research paper [1] declared conflict of interest, including receiving grants from the Physicians Foundation Center for the Study of Physician Practice and Leadership at Weill Cornell Medicine and the American Medical Association. For full details of the authors’ conflict of interest, see the research paper [1].

Editor’s comment
When it comes to generics the pharmacy has been found to have a major role to play in use of generics. However, although Medicare Part D favours generics over brand-name drugs [5], in the long term, it was found to have no impact on generics prescribing [6].

Readers interested to learn more about the influence of Medicare on use of generics are invited to visit to view the following manuscripts published in GaBI Journal:

Pharmacy chain drives choice among manufacturers of generic drugs in the US Medicare population

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To further enhance the objectives of GaBI in sharing information and knowledge that ensure policies supportive of safe biosimilars use, we are pleased to announce that we will be launching a new section on GaBI Online and GaBI Journal, the ‘Latin American Forum’ (in Spanish) featuring the latest news and updates on research and developments in generic and biosimilar medicines in Latin America.

Register to receive the GaBI Latin American Forum newsletter. Inform colleagues and friends of this new initiative.



Para fomentar los objetivos de GaBI sobre la difusión de información y conocimiento sobre las políticas de apoyo que garantizan el uso seguro de medicamentos biosimilares, nos complace anunciar el lanzamiento de una nueva sección en GaBI Online y GaBI Journal, el ‘Latin American Forum’ (en español), que presentará las últimas noticias y actualizaciones en investigación y desarrollo sobre medicamentos genéricos y biosimilares en Latinoamérica.

Regístrese para recibir el boletín informativo GaBI Latin American Forum. Informe a colegas y amigos sobre esta nueva iniciativa. 

1. Dean EB, Johnson P, Bond AM. Physician, practice, and patient characteristics associated with biosimilar use in Medicare recipients. JAMA Netw Open. 2021;4(1):e2034776.
2. GaBI Online - Generics and Biosimilars Initiative. Biosimilars approved in the US []. Mol, Belgium: Pro Pharma Communications International; [cited 2021 Apr 16]. Available from: 
3. GaBI Online - Generics and Biosimilars Initiative. Biosimilar approvals and launches in the US []. Mol, Belgium: Pro Pharma Communications International; [cited 2021 Apr 16]. Available from: 
4. GaBI Online - Generics and Biosimilars Initiative. Biosimilars approved in Europe []. Mol, Belgium: Pro Pharma Communications International; [cited 2021 Apr 16]. Available from: 
5. GaBI Online - Generics and Biosimilars Initiative. Medicare Part D favours generics over brand-name drugs []. Mol, Belgium: Pro Pharma Communications International; [cited 2021 Apr 16]. Available from: 
6. GaBI Online - Generics and Biosimilars Initiative. Medicare Part D has no impact on generics prescribing in long-term care []. Mol, Belgium: Pro Pharma Communications International; [cited 2021 Apr 16]. Available from:

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