Contract Research Organization (CRO)

Key facts

Defined in

21 CFR 312.3

Transfer of obligations

21 CFR 312.52; the transfer must be described in writing

Ultimate responsibility

Stays with the sponsor under ICH E6 Good Clinical Practice

What is a contract research organization?

FDA regulations define a CRO as a person that assumes, as an independent contractor with the sponsor, one or more of the obligations of a sponsor, for example design of a protocol, selection or monitoring of investigations, evaluation of reports and preparation of materials to be submitted to FDA.

CROs range from global full-service firms that run entire multinational programs to niche providers that handle a single function, therapeutic area or region. Drug and device companies of every size use them, and smaller biotechs without large clinical operations teams often depend on them for most trial execution.

How sponsors work with CROs

Under 21 CFR 312.52, a sponsor may transfer any or all of its obligations to a CRO, and the transfer must be described in writing. Any obligation not covered in writing stays with the sponsor. Commonly outsourced services include:

• Feasibility, site identification and site activation.
• Clinical monitoring and site management.
• Data management, biostatistics and medical writing.
• Pharmacovigilance and safety reporting.
• Regulatory submissions, and central laboratory or imaging services.

CRO vs sponsor responsibility

Hiring a CRO does not hand off accountability. ICH E6 Good Clinical Practice guidance states that the sponsor keeps ultimate responsibility for the quality and integrity of trial data, while FDA regulations make a CRO that assumes an obligation subject to the same regulatory action as a sponsor for that obligation.

Contracts usually follow either a full-service model, where one CRO runs the study, or a functional service provider (FSP) model, where vendors supply specific roles under the sponsor's management.

Why CROs matter

Because CROs run a large share of industry-sponsored trials, their site networks and investigator relationships shape where trials are placed. For site networks and clinical technology vendors, CROs are major buyers and gatekeepers, and CRO capacity affects trial timelines and costs.

ClinicalTrials.gov records usually do not name the CRO, so linking a trial to its CRO typically requires press releases, company disclosures or site-level information.