Categories are aligned with the WHO's understanding of the different phases of clinical trials and with the legal framework governing medicinal products for human use in the EU. This is a general categorisation that does not go into the specifics of individual disease areas' classifications, for which there may be different definitions.
Phase I. This refers to the first stage of testing an investigational medicinal product (IMP) in humans. It typically involves a small group of healthy volunteers (e.g., 20 to 80 human subjects), sometimes it may include patients in the target conditions, and focuses on determining the safety (e.g., to determine a safe dosage range and to identify side effects), tolerability, and pharmacokinetics (how the IMP is absorbed, distributed, metabolized, and eliminated).
Phase II. This phase tests IMPs that have been found to be safe in phase I and assesses proof of concept/ efficacy in regard to the target condition. It may involve the use of different dosing regimens or patient populations and typically involves a larger group of human subjects (several hundred). It aims to gather preliminary data on efficacy and further evaluate safety by monitoring adverse effects.
Phase III. This phase involves larger groups of human subjects (from several hundred to several thousand) and aims to confirm the efficacy and safety of the IMP in a diverse population (e.g., different regions and countries). These trials are often randomised and controlled (using a placebo or standard treatment) to provide strong evidence for regulatory approval, such as information that will allow the IMP to be used safely.
Phase IV. This phase occurs after the medicinal product has been approved and is on the market. It involves monitoring the long-term safety and effectiveness of the medicinal product in a real-world setting, often with a larger and more diverse patient population than the earlier phases.
Phase 1 - Device discovery and concept. This initial phase focuses on identifying a medical need or opportunity and exploring potential device concepts. It involves brainstorming, researching existing technologies, and conducting a preliminary risk assessment to identify potential hazards and safety concerns associated with the
proposed device.
Phase 2 – Device design and prototype. In this phase, the initial device concept is further developed and refined. This involves creating detailed specifications, developing prototypes, and conducting feasibility studies to evaluate the technical and practical viability of the device. The focus is on demonstrating that the device concept can be realised and perform as intended.
Phase 3 – Verification and validation. This is the core development phase where the device design is finalised and detailed engineering work is carried out. This includes creating detailed drawings, building working prototypes, and conducting rigorous testing to verify that the device meets its design specifications (verification) and validates that it performs its intended function safely and effectively (validation).
Phase 4 - Final validation and product launch preparation. This phase focuses on conducting final validation testing on the finished device to ensure it meets all regulatory requirements and performs as expected in the intended use environment. It also involves preparing for product launch, including developing marketing materials, training materials, and establishing distribution channels.
Phase 5 - Production, market introduction and post-market follow-up. This phase involves scaling up production of the device, launching it into the market, and providing ongoing support to users. It also includes post-market surveillance to monitor the device's performance and safety in real-world use and to collect feedback from users.