ImmunoGen, a provider of antibody-drug conjugates (ADCs) for the treatment of cancer, has announced that the first patient has been dosed in FORWARD I, the company's phase III clinical trial evaluating mirvetuximab soravtansine as a single-agent therapy for the treatment of platinum-resistant ovarian cancer. Mirvetuximab soravtansine is a first-in-class, folate receptor alpha (FRα)-targeting ADC.

"Dosing the first patient in our phase III FORWARD I study marks an important milestone in our efforts to deliver mirvetuximab soravtansine to patients in need and to drive innovation in the field of ADCs. Mirvetuximab soravtansine has the potential to meaningfully improve the lives of patients with platinum-resistant ovarian cancer, and our top priority is advancing this program as quickly as possible," said Anna Berkenblit, M.D., vice president and chief medical officer of ImmunoGen.

"Given the prognosis for most patients with platinum-resistant ovarian cancer is poor and the benefit of approved agents is modest, we need better therapies that offer improved outcomes in terms of efficacy and tolerability," said Kathleen Moore, M.D., FORWARD I co-principal investigator, and associate professor, Stephenson Cancer Center, University of Oklahoma. "We are excited about the potential of mirvetuximab soravtansine and are looking forward to evaluating this promising agent in a pivotal study."

FORWARD I is a phase III trial in which 333 patients will be randomized 2:1 to receive either mirvetuximab soravtansine or the physician's choice of single-agent chemotherapy (pegylated liposomal doxorubicin, topotecan, or weekly paclitaxel). Eligible patients will have been diagnosed with platinum-resistant ovarian cancer that expresses medium or high levels of FRα and will have been treated with up to three prior regimens. The primary endpoint of this study is progression free survival (PFS), which will be assessed in the entire study population and in the subset of patients with high FRα expression. ImmunoGen estimates that 12,000-14,000 patients per year in the U.S. meet these criteria, with a comparable number in the major markets in Europe.

ImmunoGen is partnering with the GOG Foundation, a provider of clinical research in gynecologic malignancies, on FORWARD I, which is being conducted in North America and Europe. This trial is intended to support full marketing approval of mirvetuximab soravtansine for patients with platinum-resistant ovarian cancer.