ImmunoGen has announced a collaboration with Hangzhou Zhongmei Huadong Pharmaceutical Co, a subsidiary of Huadong Medicine, to develop and commercialize the ovarian cancer treatment mirvetuximab soravtansine to patients in China, Hong Kong, Macau, and Taiwan. The partnership will combine ImmunoGen's expertise in cancer medication development with Huadong Medicine's familiarity with regulatory agencies and connections to healthcare organizations within the Asian countries. "With extensive regional experience, the right development and regulatory capabilities, and access to a deep local network of hospitals and clinics across Greater China, Huadong Medicine is an ideal partner for us,” Mark Enyedy, president and CEO of ImmunoGen, said in a press release. The subject of the companies' collaboration, mirvetuximab soravtansine, is an antibody-drug conjugate or ADC, a class of medications that combine monoclonal antibodies and anti-cancer agents. The antibodies are targeted against a certain cancer protein, which allows the toxic agent to be delivered specifically to cancer cells. In the instance of mirvetuximab soravtansine, known as mirvetuximab, the antibody targets the protein folate receptor alpha, which is overly produced in several tumor types, including ovarian cancer. This antibody is linked to a molecule called ravtansine (DM4), which is toxic to cells because it disrupts an integral cellular component called microtubules. A previous Phase 3 trial (NCT02631876) suggested that mirvetuximab could be effective in a group of patients whose ovarian cancer is resistant to traditional, platinum-based chemotherapies and expresses high levels of FR alpha. However, benefits in this trial were only observed in a later analysis, in which researchers used a different scoring method than that originally used in the trial to determine FR alpha levels. The findings are now being confirmed in two ongoing Phase 3 trials, which are expected to support regulatory approval of mirvetuximab for this indication. The first study is called SORAYA (NCT04296890) and is enrolling approximately 100 women — all of whom will receive the active treatment — at 34 sites in the U.S. and Europe. This trial is currently recruiting participants. ImmunoGen expects this trial to support accelerated approval of the medication for women with FR-alpha-high ovarian cancer, who received up to three previous treatment regimens. The trial is evaluating the proportion of patients responding to treatment and the duration of such responses — the two measures on which accelerated approvals are usually based. MIRASOL (NCT04209855), as the second trial is known, will then serve to confirm mirvetuximab soravtansine's benefits over standard-of-care treatments. Its results potentially can be used to turn the therapy's conditional approval into a full approval. This trial is recruiting 430 participants with FR-alpha-high ovarian cancer, also given up to three prior treatment regimens, at 86 locations in the U.S., Australia, Canada, Europe, Taiwan, and South Korea. Participants will be randomly assigned to receive mirvetuximab or chemotherapy of the investigator's choice. The main goal is to determine whether mirvetuximab extends the time patients live without signs of disease worsening, compared with chemo, and key secondary objectives include safety and tolerability, the proportion of patients responding to treatment, overall survival, and patient-reported outcomes. “The compelling clinical data generated to date highlights mirvetuximab’s potential to be a promising therapy for an extremely difficult to treat disease and we look forward to beginning its development as we seek to meet the growing needs of ovarian cancer patients in Greater China," said Liang Lu, chairman of Huadong Medicine. "ImmunoGen is a leader in the development of ADCs for the treatment of cancer and this partnership provides us with a late-stage asset that will enable us to further expand our pipeline of innovative oncology programs,” Lu added. Under the terms of the collaboration, ImmunoGen will receive an upfront payment of $40 million, with additional milestone payments throughout development and commercialization that could total $265 million. The company also would be eligible for royalties from potential sales. ImmunoGen, which expects the treatment to be commercialized in the U.S. by 2022, also retains the rights to mirvetuximab soravtansine in all other countries. “This collaboration reflects mirvetuximab’s potential to deliver meaningful value to ovarian cancer patients as well as our ability to translate our work in ADCs into long-term relationships that create sustainable value for ImmunoGen and our partners," Enyedy said. "We look forward to working closely with Huadong Medicine to develop and commercialize mirvetuximab in Greater China as we advance the mirvetuximab program and prepare for the first potential commercial launch in the United States in 2022.” Huadong will be responsible for all potential regulatory agency submissions and commercialization, though a steering committee with members from both companies will advise these processes.