An investigator-initiated study (IIS) is clinical research that an external investigator, usually a physician at an academic center or hospital, designs, sponsors, and runs, with a pharmaceutical, biotech, or medical device company providing support such as funding, study drug, or devices. The idea comes from the investigator, not the company. The investigator or their institution writes the protocol, holds the regulatory responsibilities, and owns the data, while the company decides whether to support the proposal and tracks what it agreed to provide.
Quick answer: In an IIS the investigator is the sponsor. Under FDA's definition in 21 CFR 312.3, a sponsor-investigator both initiates and conducts the study and carries the duties of both roles. The company's part is to review the proposal against its research priorities, agree a contract, provide the support, and follow the milestones through to publication. The same arrangement is also called investigator-initiated research (IIR), an investigator-initiated trial (IIT), or an investigator-sponsored study (ISS).
The split of responsibility is what defines an IIS. FDA's regulation on investigational new drugs, 21 CFR 312.3, defines a sponsor as the person or organization that takes responsibility for and initiates a clinical investigation, and a sponsor-investigator as an individual who both initiates and conducts it. In an IIS, that individual or their institution is the sponsor. They write the protocol, obtain ethics approval, register the study, enroll patients, collect the data, and publish the results.
The company supports the study but does not run it. Medical affairs usually owns the relationship: it publishes the areas of research the company is interested in, reviews proposals, records the decision, signs the agreement, and tracks milestones and payments. An MSL may be the investigator's first contact and may pass a proposal along, but the MSL does not design the study or decide whether it is funded.
The term is easiest to understand next to the alternatives a medical affairs team also handles.
| Study type | Whose idea | Who is the sponsor |
|---|---|---|
| Investigator-initiated study | The external investigator | The investigator or institution |
| Company-sponsored clinical trial | The company | The company |
| Company-sponsored non-interventional or real-world study | The company | The company |
| Research collaboration | Shared | Set by the agreement |
An IIS can itself be interventional, like a small trial testing a new dose or combination, or observational, like a registry or chart review that generates real-world evidence. What makes it an IIS is who started it and who sponsors it, not the design.
Investigator-initiated studies often answer questions a company's own program does not: a patient group the pivotal trial excluded, a use in routine practice, a new combination, or a mechanism question an academic group is well placed to explore. The MAPS 2025 guidance on strategic integrated evidence generation planning includes a section on implementing them and describes how they can expand product knowledge and show how a product is used in real-world practice, alongside company data.
For that reason, most companies review proposals against the evidence gaps in their integrated evidence plan rather than case by case. A proposal that addresses a priority gap has a clear reason to be supported. One that does not may still be good science, but the company's decision should say why it was or was not funded.
Support for an IIS must be tied to the research, not to the investigator's prescribing. The decision should rest on scientific merit and fit with the company's research priorities, led by medical and scientific reviewers, and it should not depend on the investigator's prescribing or on sales goals. Payments usually follow agreed milestones, and the budget should reflect what the work actually costs, in line with fair market value principles. Company support to physicians and teaching hospitals for research is also reported publicly in the US through Open Payments.
The full process, from intake and review to milestones and the final manuscript, is covered in how medical affairs runs an investigator-initiated study.
Because the company does not run the study, it needs a separate oversight record to know where each one stands. TikaStudies keeps investigator-initiated studies in one medical affairs portfolio with the principal investigator, institution, milestones, documents, and spend, and stores the ClinicalTrials.gov identifier without filing the registry record. It is an oversight record, not a clinical trial system.
It is clinical research designed, sponsored, and run by an external investigator or institution, with a pharmaceutical, biotech, or medical device company providing support such as funding, study drug, or devices. The investigator, not the company, is the sponsor.
In a company-sponsored trial, the company designs the study and acts as the regulatory sponsor. In an investigator-initiated study, the external investigator proposes and designs it, acts as sponsor-investigator, and holds the regulatory duties, while the company only supports it.
In practice, yes. Investigator-initiated study, investigator-initiated trial, investigator-sponsored study, and investigator-initiated research all describe research an external investigator proposes and sponsors with company support. Companies differ in which term they use.
Usually a cross-functional review group led by medical affairs, which assesses the proposal's scientific merit and fit with the company's research priorities. The decision should not depend on the investigator's prescribing or on sales goals, and it should be recorded with its reason.
If your team tracks supported studies across inboxes and spreadsheets, we can walk through how one study looks from proposal to manuscript on one record.
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