Conducting clinical trials is an integral part in developing new, safe, and efficacious pharmaceutical products. Exposing study volunteers to an experimental drug, particularly in the early stages of development, is challenging because of the limited information on the functional performance of the drug candidate. Regulatory guidances and formal control and approval procedures are in place to reduce risks and safety threats to study volunteers. This article discusses the management of risks in pharmaceutical quality of clinical-trial supplies, particularly the challenges that occur for early-stage clinical trial materials for which knowledge of the drug compound is limited. The basic dilemma that seems difficult to fully circumvent is that one is gaining knowledge about the importance of quality attributes through the development process, yet the application of GMPs is predicated on that knowledge. The authors examine this dilemma and resolution in several areas: step-wise modifications of test products, the concept of "representative," genotoxic impurities, specifications and acceptance criteria, and stability studies.
This situation creates a dilemma for industry and regulators: one is still gaining knowledge about quality attributes during development, but application of cGMPs is based on the knowledge that is being acquired. More uncertainty about what is important to quality exists in early development compared with later in development as a product design matures and moves to commercial approval. This knowledge gap means that it is impossible to implement the same level of cGMPs at Phase Ia as compared with a commercial drug product.
Although authorities generally do not expect the same level of cGMPs throughout development, there is little specific regulatory guidance on expectations for early development or for the various stages of development. As a result, International Conference on Harmonization (ICH) guidances on quality and other guidelines that are designed for commercial products are applied unevenly and unpredictably to early-development clinical trial materials because the consideration of quality varies from reviewer to reviewer and company to company. This inconsistency affects issues relating to specifications, shelf-life and stability, starting materials and the description of an API synthesis, and potential impurities.