An Investigator-Initiated Trial (IIT) is a clinical study initiated, planned, and sponsored by a physician, a research group, or an academic institution—rather than a pharmaceutical company or a medical device manufacturer. In this context, the investigator simultaneously assumes the role of the sponsor as defined by EU Regulation No. 536/2014 (CTR) and bears full regulatory responsibility for the planning, conduct, monitoring, documentation, and reporting of the study. Investigator-initiated trials are a vital component of independent clinical research and frequently provide evidence that industry-sponsored trials do not generate for economic reasons. Especially in academic medicine and for rare diseases, IITs are indispensable for scientific progress.
Distinction: IIT vs. Industry-Sponsored Trial
The fundamental difference from an industry-sponsored trial lies in the distribution of responsibility and resources. In an IIT, the investigator acts as a sponsor-investigator and assumes all duties that would otherwise be borne by a pharmaceutical company:
- Submission of the clinical trial to the competent ethics committee and federal higher authority (BfArM or PEI) via the Clinical Trials Information System (CTIS)
- Preparation and submission of the Investigational Medicinal Product Dossier (IMPD), even for medicinal products that are already authorized
- Responsibility for monitoring, pharmacovigilance, and reporting of serious adverse events (SAEs) as well as SUSARs to all stakeholders and CTIS
- Management of the Trial Master File and ensuring data integrity in accordance with ALCOA principles
- Financing of the study through third-party funds, foundations, or investigator grants
- Preparation of the Clinical Study Report and, if applicable, publication of the results in peer-reviewed journals
Industry-sponsored trials, on the other hand, are initiated, financed, and regulatorily managed by the pharmaceutical company. In such cases, the investigator is primarily responsible for recruitment, treatment, and documentation at the trial site, while the sponsor bears the overarching regulatory obligations. This division of labor is entirely absent in an IIT.
Regulatory framework in the EU
Investigator-initiated trials involving medicinal products are subject to the same regulatory requirements in the European Union as industry-sponsored trials. Since EU Regulation No. 536/2014 became fully applicable, IITs must be submitted via the Clinical Trials Information System and approved by the competent ethics committee and federal higher authority. In Germany, either the BfArM or the PEI is involved, depending on the investigational medicinal product.
Particular challenges for academic sponsors arise from the following regulatory requirements:
- Preparation of a full IMPD, even for authorized medicinal products (a simplified IMPD with reference to the product information is possible)
- Ongoing pharmacovigilance reporting obligations, including SUSAR reporting to CTIS and notification of all trial sites within the statutory reporting deadlines
- GCP-compliant monitoring by qualified personnel with appropriate training and documented experience
- Requirements for clinical trial medication logistics, labeling, and traceability of the investigational medicinal product in accordance with Annex VI of the CTR
- Obligation to report study results in CTIS within twelve months of the end of the study (Art. 37 CTR)
Financing and Conflicts of Interest
IITs play an important role in clinical research, particularly for indications with low commercial interest such as rare diseases (orphan diseases), pediatric diseases, or combination therapies of active substances that are already off-patent. They enable independent, interest-free evidence generation and often form the basis for guideline recommendations from national and international professional societies.
Typical funding sources for IITs include public funding programs such as the German Research Foundation (DFG) or the Federal Ministry of Education and Research (BMBF), EU Horizon programs, foundations, and unrestricted grants from pharmaceutical companies. The distinction between an unrestricted grant and a sponsored study is of central regulatory and ethical importance: if a pharmaceutical company gains influence over design, data evaluation, or publication, the study loses its IIT character and becomes an industry-sponsored trial, with far-reaching consequences for approval requirements and conflict-of-interest declarations.
Relevance for clinical trials
Due to the extensive regulatory requirements, conducting an IIT presents academic institutions and investigators with significant operational challenges. The requirements for monitoring, pharmacovigilance, and documentation correspond fully to those of large Phase III trials—often with significantly fewer resources. Full-service CROs like mediconomics support sponsor-investigators with study planning, regulatory affairs submissions via CTIS, GCP-compliant monitoring, and the preparation of the Clinical Study Report, allowing investigators to focus on their scientific work.
Frequently Asked Questions (FAQ)
What regulatory obligations does a sponsor-investigator have in an IIT?
A sponsor-investigator assumes all duties of a sponsor under EU Regulation No. 536/2014: CTIS submission, IMPD preparation, pharmacovigilance including SUSAR reporting, GCP-compliant monitoring, management of the Trial Master File, reporting of results in CTIS, and preparation of the Final Clinical Study Report. These duties are identical to those of an industrial sponsor and require significant resources and specialized professional staff.
Can an investigator delegate operational tasks to a CRO?
Yes. The sponsor-investigator can delegate operational tasks such as monitoring, pharmacovigilance reporting, or data management to a Contract Research Organization (CRO). However, the overall regulatory responsibility remains with the sponsor-investigator. The delegation must be documented in writing in a service agreement that complies with GCP requirements according to ICH E6(R3) and defines clear responsibilities.
Does the CTR Regulation 536/2014 also apply to small academic IITs?
Yes, as long as it is an interventional clinical trial with medicinal products, the requirements of EU Regulation No. 536/2014 apply regardless of the study size or the academic context. Non-interventional studies (observational studies) are excluded; these are subject to their own national regulations and do not trigger a CTR approval requirement.
Regulatory References
- EU Regulation No. 536/2014 (CTR) – Clinical trials on medicinal products for human use: Art. 2 (Definitions), Art. 37 (Reporting of results), Annex VI (Investigational medicinal products)
- ICH E6(R3) – Good Clinical Practice (2023): Sponsor and investigator responsibilities, monitoring, delegation
- German Medicines Act (AMG) Sections 40–42b: National implementation of CTR requirements in Germany
- EMA Guideline on Investigator Brochures for Non-commercial Clinical Trials (EMA/CHMP/91754/2011)
- BMBF Funding Program for Clinical Trials: Requirements for academic sponsors and funding conditions