On the second day of the 2019 National Comprehensive Cancer Network (NCCN) Annual Conference (March 21-23, 2019; Orlando, FL), Gary H Lyman, MD, MPH, Fred Hutchinson Cancer Research Center/Seattle Cancer Care Alliance, discussed biosimilars in oncology care, providing an overview of what biosimilars are, an update on new developments, and a forecast of how biosimilars may impact cancer costs and treatment.
The American Society of Clinical Oncology (ASCO) issued an official statement on biosimilars in oncology in 2018, offering guidance on the concerns surrounding biosimilar safety, interchangeability, value, and regulatory considerations. The bottom line of the statement, Dr Lyman said, is that biosimilars will play an important role in the future care of patients with cancer.
The FDA definition of a biosimilar is: “a biological product that is highly similar to a US-licensed reference biological product for which there are no clinically meaningful differences in safety, purity, or potency of the product.” Monoclonal antibody biologics, as compared with chemical drugs like aspirin, are large with a high molecular weight and are complex/heterogeneous. They are living cells/organisms, Dr Lyman said, and impossible to ensure identical copies in manufacturing. They are unstable and sensitive to external conditions.
He briefly touched on the complex naming convention for biosimilars. They are named with the nonproprietary name of the reference product + a 4-letter suffix that is unique and devoid of meaning (designated by the FDA). This naming procedure is important for pharmacovigilance of specific products and to maintain a level playing field for all biosimilar products when there are multiples of the same reference product.
As far as what the future holds, Dr Lyman discussed the possible status of some biosimilars as an “interchangeable biosimilar”; this designation would require a biosimilar to be approved both as a biosimilar (same clinical result as reference product), but also have additional clinical data demonstrating that switching back-and-forth or between the reference product does not produce any meaningful difference in efficacy or safety. Thus, “interchangeable” biosimilars would indicate that they have passed through higher standards for approval. No biosimilars in the US currently do have this status, he said.
Europeans, Dr Lyman noted, have been approving biosimilars since over 10 years ago, while the US only approved their first one, filgrastim‐sndz, in 2015. Filgrastim-sndz has been approved for all indications of the originator filgrastim. Three more were approved in 2016; five more in 2017; and nine more in 2018/19. Many more biologic patents are going to expire in the US before 2020. With multiple biosimilars available for the same reference drug, Dr Lyman said, this is where the market may see competition begin to drive down drug costs.
He acknowledged the persistent concerns surrounding biosimilars. Physicians are still skeptical of efficacy, safety, and impact on reimbursement and also concerned that use will be forced upon them. There is a perception that cost is the main issue for biosimilars. Dr Lyman said that strong clinical data will be important for increased acceptance. In addition, while we can speculate how they will impact the market, there is no way to know exactly how biosimilars will affect cost or if they will improve access. However, we may be able to learn from how biosimilars have fared in Europe, as they have been used for a longer time there.
Over 25 biosimilars have been approved in Europe since the first one in 2006; since then, none have been withdrawn or suspended. Over the last 10 years, the EU monitoring system for safety concerns has not identified any relevant difference in the nature, severity, or frequency of adverse effects between biosimilar medicines and their reference medicines.—Amanda Del Signore
Read the interview on biosimilars and clinical pathways that JCP conducted with Dr Lyman in August 2018.
Read the ASCO statement on biosimilars.