Investigator Brochure (IB)
What a definition is not
A definition is SPEQ’s plain-language decode of how a term is used in practice, cited to the documents that define it. It is a practitioner reference, not legal or regulatory advice, it does not replace the definition in the source, and where a regulator’s wording differs the regulator’s wording governs.
A compiled summary of the clinical and nonclinical data on an investigational product that is relevant to its study in human subjects, given to investigators before a trial begins. It supports informed risk assessment, guides safety monitoring and dose selection, and is updated as new data emerge, forming the reference point for judging whether an adverse event is expected.
The IB assembles everything an investigator needs to weigh the risks of enrolling subjects: pharmacology, toxicology, pharmacokinetics, prior human experience, and a summary of known or expected adverse reactions. It is written to be understood by clinicians, not regulators — the emphasis is practical risk management at the bedside, not a full technical dossier.
Its most consequential role is as the reference safety information investigators and sponsors compare new adverse events against. An event that is not consistent with the pattern described in the current IB is “unexpected,” which is one of the three criteria that turns a serious adverse event into a SUSAR requiring expedited reporting.
Because the safety picture of an investigational product changes constantly, the IB is reviewed at least annually and revised whenever significant new information emerges — a new drug interaction, a class-effect signal, or updated nonclinical toxicology. Sites and ethics committees must be working from the current version before enrollment continues.
- —Serves as the reference safety information used to judge whether an adverse event is “expected” or “unexpected,” which determines SUSAR status.
- —Reviewed and updated at least annually, or whenever significant new safety information becomes available.
- —Required reading for investigators and IRBs/ECs before a trial can open at a site.
- —Distinct from an approved product label — it covers investigational, not yet approved, indications, doses, and populations.
ICH E6(R3) GCP, Section 7 (Investigator’s Brochure); 21 CFR 312.23 (IND Content and Format)
Frequently asked questions
What is Investigator Brochure (IB)?
A compiled summary of the clinical and nonclinical data on an investigational product that is relevant to its study in human subjects, given to investigators before a trial begins. It supports informed risk assessment, guides safety monitoring and dose selection, and is updated as new data emerge, forming the reference point for judging whether an adverse event is expected.
Which regulations cover Investigator Brochure (IB)?
ICH E6(R3) GCP, Section 7 (Investigator’s Brochure); 21 CFR 312.23 (IND Content and Format)