The Reality of Cancer Biosimilars: Challenges and New Hope

Although cancer biologics are clinically effective, various challenges still surround their use. These issues include high cost, data that is highly dependent on preclinical studies, many unknowns regarding insurance coverage, and more.

“Considerable professional and patient education will be important, along with rational and sustainable policies, to ensure the appropriate and effective use of biosimilar medications in clinical practice,” wrote Gary H. Lyman, MD, MPH, a professor at the University of Washington School of Medicine, and his coauthors in a review article published in the New England Journal of Medicine.

First, the cost of biosimilars remains expensive. However, various originator products are set to lose their patents in several years. By 2020, the patents on biologics that account for more than $20 billion per year in global spending will have expired. The RAND Corporation forecasts that the introduction of biosimilars could yield $54 billion in savings between 2017 and 2026.

Several issues challenge the future acceptance of biosimilars by physicians. First, the regulatory process for the approval of biosimilars is mostly dependent on preclinical studies rather than high-power, phase III clinical trials, which could limit practitioner confidence in these therapies. Second, status-quo naming and labeling practices for biosimilars are confusing. Third, it is currently unclear how to best integrate biosimilars into clinical practice and how they will be covered by payers. Fourth, the administration of biosimilars requires an understanding of novel concepts, including extrapolation, switching or automatic substitution, and interchangeability. Finally, small differences in manufacturing could lead to discrepancies in immunogenicity and adverse event profiles cropping up over time, which will require dedicated postapproval surveillance.

To address these challenges, Lyman and colleagues offered several suggestions in their review article. For instance, they propose that robust education and training about biosimilars should be offered to clinicians and patients. Governments and professional associations can also disseminate educational materials. Furthermore, improvements in the collection of postmarketing data, including addressing interoperability issues in EHR and administrative burden on physicians, could help. Finally, legislative changes might facilitate the coverage of these drugs in a manner that ensures cost savings.

In 2018, the American Society of Clinical Oncology released a statement that expands on the safety, efficacy, and integration of biosimilars into practice, as well as naming, labeling, and regulatory practices. This guidance is a step in the right direction. 

Biosimilars are biologic agents that are similar, but not exactly the same, as currently approved reference biologic agents; they offer no noticeable differences in efficacy, safety, and purity. The first wave of biosimilar cancer treatments included bevacizumab-awwb (Avastin alternative) and trastuzumab-dkst (Herceptin alternative) for the direct treatment of cancer, as well as filgrastim-sndz (Neupogen alternative) for chemotherapy toxicity.