Under the BPCIA, the FDA Purple Book is the published agency reference on biosimilars. It lists very specific information with regard to both the reference biologics and biosimilars: (1) biologic licensing application number, (2) nonproprietary name, (3) proprietary name (brand name), (4) date of licensure, (4) reference product exclusivity expiration, and (5) whether the product is a biosimilar or interchangeable product.
However, the number of patents existing on a specific reference product and the complex nature of the web of exclusivities, has compelled several speakers at a September 4, 2018 public hearing on biosimilars to question the value of the current Purple Book information.
At the FDA-sponsored hearing, Mariana Socal, MD, PhD, MS, MPP, from the Johns Hopkins Bloomberg School of Public Health, stated that the FDA Purple Book should focus more on competition, “providing both proprietary and nonproprietary information.” She believes that “the drug identification information should be expanded,” to include administration, dosage form, strength, pediatric use, and orphan drug status. She would rather the FDA Purple Book publish much more information regarding the active ingredient, “and all unexpired exclusivity periods should be published in the Purple Book.” For those patents found to be eliglible, the 12-year reference exclusivity under BPCIA should be determined and published definitively in the Purple Book.
“The Purple Book should include information on all unexpired patents that the reference manufacturers reasonably believe protects their biologic product,” said Dr. Socal. Otherwise, it forces prospective biosimilar drug makers to sift through hundreds of complex pharmaceutical patents, “making it easy to miss a key patent.”
“The FDA is authorized to do this under the Public Health Service Act,” she stated. Increasing transparency and reducing uncertainty are building blocks of the effort to improve timeliness of access to biosimilars.
According to Dr. Socal and other speakers like Michelle Cope at the National Association of Chain Drug Stores and Christine Simmon at The Biosimilar Council, the implication is that the FDA Purple Book needs to be more of an assistive tool to improving access to biosimilars rather than simply a reference on what has been approved.