USP BIOTECH MONOGRAPHS INDIVIDUALIZED FOR STRUCTURAL DIFFERENCES

USP BIOTECH MONOGRAPHS INDIVIDUALIZED FOR STRUCTURAL DIFFERENCES, such as those involving amino acid sequence or glycosylation, was the consensus reached at a U.S. Pharmacopeia "open" conference in Corpus Christi, Texas on Sept. 27. USP Committee of Revision member Alan Gray, PhD, said in a summary of the consensus reached at the three-day conference that "if substances vary in their chemical makeup, irrespective of how slight [these variations are], there should be a separate monograph." It was agreed, Gray noted, "that this is a sensible approach in the initial stages of monograph writing." Ultimately, as data is developed, Gray added, "it may well be possible to construct single monographs that can cover two or more" substances with similar but not identical structures. * USP says it will move forward to publish separate draft monographs for the two recombinant human growth hormones, somatrem (Genentech's Protropin), somatropin (Lilly's Humatrope) and an individual draft monograph for TPA (Genentech's Activase). The drafts will be aired for public comment in a forthcoming issue of the Pharmacopeial Forum. The separate monograph approach for biotechnology-derived proteins mirrors FDA's current product-by-product approach to regulating biotech products. At the USP meeting, FDA Center for Biologics Evaluation and Review Associate Director Elaine Esber, MD, explained CBER's view that the biotech proteins are not suitable for generic review. Biotech products currently being regulated as biologics by CBER, Esber maintained, are "not simple enough" to allow FDA to standardize its control requirements between manufacturers. From CBER's regulatory perspective, Esber said, "they can't be dealt with generically." FDA will continue to regulate each manufacturer's product as a unique entity, Esber explained, because the control systems for the proteins must be tailored to the specific components, source materials, manufacturing process and biochemical structure, and must reflect the clinical experience with that particular product. The limited ability to evaluate the finished product for safety and efficacy using current methodologies puts added emphasis on process validation and testing which must be worked out on a "manufacturer-specific" basis, Esber maintained. Under debate at the Corpus Christi conference was whether specific monographs for the new biotech proteins can and should be included in the USP at this time, and if included, whether separate monographs would be needed for each manufacturer's product. The monograph debate also extended to what information on biotech process and test methodologies should be included in the general chapter section of the compendia, and what role USP should play in the development and distribution of reference standards for the new products. The conference participants included a broad cross-section of the biotech industry as well as representatives from FDA and academia and foreign compendial and regulatory organizations. The meeting consensus was that USP should move forward in publishing a draft general "information" chapter on biotechnology which would describe the types of products and technologies involved and discuss final product testing issues. The conference participants agreed that it is too early to include specific monographs for cytokines and monoclonal antibodies, or to include a general "mandatory" chapter on specific biotech test methodologies. A recurrent theme at the meeting was the need for international harmonization of standards for the biotech products, particularly regarding reference reagents. Highlighting USP's commitment to the effort, USP Executive Director-designate Jerome Halperin stated that setting standards for biotechnology products is "a very important area for international harmonization. We are at the beginning of a field and it is much easier to go forward to harmonize than it is to retrofit that which already exists in the USP and other pharmacopeias around the world."