Barriers to biosimilars access in the US

The US Food and Drug Administration (FDA) has approved 26 biosimilars [1], yet only two are available on the market. A recent exploration [2] of this issue highlights the major obstacles to biosimilar access in the US.

Drug prices, particularly for biologicals, are notoriously high in the US. There are various reasons for this, as discussed in several recent articles [3, 4], of which the poor market penetrability of biosimilars is significant.

Currently, two biosimilars are available on the US market: Inflectra (an infliximab biosimilar marketed by Celltrion/Pfizer) and Renflexis (which is also an infliximab biosimilar, marketed by Samsung Bioepis/Merck).

This issue is addressed in detail, based on the input of two experts in rheumatology [2]. As many of the FDA-approved biosimilars are for rheumatologic and inflammatory diseases, their input is highly relevant.

The discussion outlines several major obstacles to biosimilars entering the US market, summarized below:

Patent litigation

Litigation by the manufacturer of the reference product can limit biosimilar access to the market.
Even if patent litigation is not ultimately successful, it can significantly delay the entry of a biosimilar to the market.
AbbVie, for example, manufacturer of Humira (adalimumab), has delayed the launch of biosimilar versions until 2023 in the US through patent litigation cases [5, 6].

Price

The price of biosimilars can also be an issue. For some biosimilars, the discount on the reference product is not significant, which makes it less likely that insurers, physicians and patients will switch.
Early marketing for biosimilars has tended to focus on hospitals rather than community settings, where most care is actually delivered.
The recommendation is that more biosimilar manufacturers focus their marketing and pricing strategies on community settings to increase biosimilar adoption.

Prescribing behaviour

The role of physicians and other prescribers is critical.
Physician concerns about biosimilars can be a major barrier to biosimilar uptake and frequently physicians are reluctance to switch to biosimilars.
Although many physicians are conservative in the adoption of new drugs, the message that all biologicals vary is being spread and familiarity with biosimilars is increasing.
The rheumatologists say efforts should be made by doctors to become more familiar with biosimilars, to gain confidence in them, and ultimately use them more.
The role of the physician as an advocate for biosimilars is also discussed, highlighting their ability to choose to stock biosimilars and to encourage local hospitals to do the same.

Insurance system

In the US, access to biologicals (including biosimilars) is controlled by insurance providers who contract with pharmacy benefit managers (PBMs).
These companies often receive rebates from drug manufacturers which lower the price of a reference drug.
This can lead to slow uptake of biosimilars, as the difference in price between biosimilar and originator is reduced. This has been called a ‘rebate trap’ and is a significant impediment to biosimilar market penetration in the US. Originator manufacturers frequently use such rebates to incentivize payers, PBMs and pharmacies to exclude biosimilars from their formularies.

The rheumatologists say it is critical that biosimilar adoption increases in the US, or investments needed to maintain the pipeline of biosimilars may ‘dry up’ as manufacturer interest declines.

They also highlight the importance of FDA continuing its efforts, such as implementation of the Biosimilars Action Plan, to increase biosimilar uptake in the US. The agency released its Biosimilars Action Plan in July 2018. The aim of the plan is to improve the efficiency of the biosimilar and interchangeable product development and approval process. Since then FDA has also released guidances and a proposed rule to advance its biosimilars policy framework [7].

Related articles
Do patent strategies delay market entry of biosimilar monoclonal antibodies in Europe?

Reimbursement of biosimilars in the US

References
1. GaBI Online - Generics and Biosimilars Initiative. Biosimilars approved in the US [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 May 29]. Available from: www.gabionline.net/Biosimilars/General/Biosimilars-approved-in-the-US
2. Volansky R. Opening the biosimilar bottleneck: mounting FDA approvals, reduced costs may revive stunted U.S. market. Healio Rheumatology. 2020 [online].
3. GaBI Online - Generics and Biosimilars Initiative. How to make biological drugs more affordable [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 May 29]. Available from: www.gabionline.net/Biosimilars/Research/How-to-make-biological-drugs-more-affordable
4. GaBI Online - Generics and Biosimilars Initiative. Why does the US face high-priced generics and drug shortages? [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 May 29]. Available from: www.gabionline.net/Generics/Research/Why-does-the-US-face-high-priced-generics-and-drug-shortages
5. GaBI Online - Generics and Biosimilars Initiative. AbbVie makes more deals delaying adalimumab biosimilars in the US [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 May 29]. Available from: www.gabionline.net/Pharma-News/AbbVie-makes-more-deals-delaying-adalimumab-biosimilars-in-the-US
6. GaBI Online - Generics and Biosimilars Initiative. AbbVie and Coherus sign licensing deal for Humira biosimilar [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 May 29]. Available from: www.gabionline.net/Pharma-News/AbbVie-and-Coherus-sign-licensing-deal-for-Humira-biosimilar
7. GaBI Online - Generics and Biosimilars Initiative. FDA releases guidances and proposed rule to advance biosimilars policy framework [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2020 May 29]. Available from: www.gabionline.net/Guidelines/FDA-releases-guidances-and-proposed-rule-to-advance-biosimilars-policy-framework

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