Preclinical Phase: A single promising anti-TB development candidate has
been selected to advance into preclinical studies to determine if the
agent is likely to be safe and effective for use in humans.
Activities for candidates in this phase include: Animal model efficacy
studies, GLP and non-GLP animal pharmacology, safety, PK/PD, ADME and
toxicology studies to prepare documentation for regulatory submission;
toxicity studies in two animal species (rodent and non-rodent) including
dose-escalation, repeat dose and both short-term and long-term exposure
studies; process development chemistry to ensure that production of the
active agent can be scaled up; and stability testing of the agent.
Phase 1: A trial designed to assess the safety, tolerability, and
pharmacokinetics of a candidate drug in a small (20-100) group of
Phase 2: A trial designed to assess safety and efficacy of a candidate
drug on small groups of tuberculosis patients (20-300). Phase 2 studies
are sometimes divided into Phase 2A and Phase 2B. Phase 2A is
specifically designed to assess dosing requirements. Phase 2B is
specifically designed to study efficacy at the prescribed dose(s).
Phase 3: A randomized controlled, multicenter trial on large patient
groups (300-3,000 or more) that is aimed at being the definitive
assessment of candidate drug efficacy, in comparison with the 'gold