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Cancer Clinical Trials API

NCI is redesigning the way patients and oncologists find information and learn about cancer clinical trials by making NCI-supported cancer clinical trials available through an application programming interface (API). An API helps translate large amounts of data in meaningful ways and is primarily used to allow two computer applications to talk to each other in a common language that they both understand.

This Clinical Trials API will enable the community—advocacy groups, academia, and others in the cancer clinical trials ecosystem—to build applications, integrations, search tools, and digital platforms tailored to individual communities that bring clinical trial information to more providers, patients, and their family members.

Are you developing a digital product around cancer information or cancer clinical trials?

NCI's clinical trial search is now powered by the beta version of the Clinical Trials API and allows NCI to begin providing better search results. The information made publicly available by the Clinical Trials API draws from the Clinical Trials Reporting Program (CTRP) database. This CTRP information does not include regulatory information such as IRB approval details, IND/IDE information, NCI-specific Data Table 4 information, or biomarker data. In addition, no accrual information, patient-level or summary, is made public. A beta API is an initial working piece of software on the public web for use and feedback, and NCI wants to hear your ideas or comments on how we can improve the API in the next version.

Ready to use the Clinical Trials Beta API?

Documentation for developers can be found on


To give us feedback on the Clinical Trials Beta API, or if you need help or have any questions, please contact

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