Biotechnology company Immunogen (IMGN - Get Report)  was down more than 45% in trading Friday after the company's ovarian cancer treatment candidate failed to meet the primary endpoint in a phase 3 trial.

The trial evaluated the efficacy of its treatment candidate compared to the results of treatment with chemotherapy in patients with folate receptor alpha positive, platinum-resistant ovarian cancer. 

"Even though FORWARD I did not meet its primary endpoint, I continue to be impressed with the efficacy and tolerability of mirvetuximab soravtansine in ovarian cancer patients, especially in the subset with high FRα expression," said Dr. Kathleen Moore, associate director of clinical research at the Stephenson Cancer Center at the University of Oklahoma. "I look forward to continuing to work with ImmunoGen to analyze the Phase 3 data and determine the most appropriate path to bringing mirvetuximab soravtansine to those patients who benefit most from it."

The overall response rate for the company's treatment was ultimately higher than for those in the study who were treated with chemo> However, there wasn't a significant difference in overall survival rates. 

"We want to thank the patients who participated in this trial, the clinical investigators, and the support staff for their hard work, as we continue to pursue our goal of finding innovative cancer treatments for patients in need," said Dr. Anna Berkenblit, senior vice president and chief medical officer of ImmunoGen.