The slate of biosimilars for cancer is growing, and with this expansion the potential for price competition has improved.
Hope Rugo, MD
The slate of biosimilars for cancer is growing, and with this expansion the potential for price competition has improved. In November 2019, LA-EP2006 (pegfilgrastim-bmez; Ziextenzo) became the sixth biosimilar for cancer to get FDA clearance so far this year and the 15th biosimilar indicated for cancer on the US market (Figure).1 Unlike generic drugs, biosimilars slightly differ from their reference or originator drugs and therefore undergo a separate FDA review process. In US oncology, the use of biosimilars dates to 2015, when the FDA accepted filgrastim-sndz (Zarxio).
In May of this year, the agency issued guidance on how manufacturers can achieve “interchangeable” status for their biosimilars, which would facilitate prescribing.2 The information acquaints biosimilar manufacturers with the standards that will guide the FDA’s review of all biosimilars submitted for evaluation. In the US market, no biosimilars have yet achieved this status.3
To obtain FDA approval as a biosimilar, the drug must be “highly similar” to the originator product based on analytic tests, toxicity studies, and clinical studies that demonstrate safety, purity, and potency.4 “It can’t show immunogenicity that’s different from the originator product and then it has to have clinical similarity in a specific setting,” Hope S. Rugo, MD, FASCO, director of Breast Oncology and Clinical Trials Education, University of California San Francisco Helen Diller Family Comprehensive Cancer Center, said in an interview with OncologyLive®.5
Although a generic drug takes an average of 3 years to develop, a biosimilar by contrast requires approximately 7 to 8 years.6 The length of this process contributed to Pfizer’s recent decision to redirect funding from 5 of its preclinical biosimilar programs to late-stage programs in disease areas with unmet need or limited treatment options, because the biosimilars would not have been available “for at least 4 to 8 years.”7
Unexpired patents for originator drugs also limit biosimilar market entry. These products cannot enter the market until the original agent’s patent expires. For example, a biosimilar competitor for nivolumab (Opdivo) is not expected to be available before 2024.8