In February 1992, with support from the Southwest Oncology Group (SWOG), one of the largest cancer clinical trials cooperative groups in the United States, a program was established to encourage leading oncology specialists from Japan and the United States to exchange information about cancer treatment. Under the program, a series of joint meetings, called "U.S.-Japan Clinical Trials Summit", were held focusing on cancers of the ovarian, uterine, bladder, prostate, gastric, esophageal, bone and soft tissue, lung, head and neck, and breast. Discussions at these joint meetings led to the conclusion that U.S.-Japan collaborative research was essential to make further progress in research.
At the 6th Joint Meeting on the topic of lung cancers, held in San Francisco in November 1998, a proposal for a randomized controlled trial on advanced non-small cell lung cancer was presented. In Japan, however, there was no such organization to support a large-scale multinational trial, which prevented research being carried out smoothly.

Based on these backgrounds, with key members of U.S.-Japan Clinical Trial Summit working together, "The Japan-Multinational Trial Organization" was established in October 1999. Then, in August 2005, the organization was restructured and named "Limited Liability Intermediate Corporation The Japan-Multinational Trial Organization," and in June 2009, according to reform of the system of public service corporations, shifted to a not-for-profit corporation and named "General Incorporated Association The Japan-Multinational Trial Organization."

The main objective of the organization is to support clinical trials, especially multicenter or multinational randomized controlled trials, for the diagnosis, treatment and prevention of diseases.
The organization aims to conduct clinical trials of combined modality therapy with:
・ New or already-approved drugs
・ Surgery
・ Radiotherapy,
to develop more effective and safer treatments, and to improve more rapidly the survival and quality of life for patients.