Shares in ImmunoGen fell 32% in premarket trading after the firm said the FDA had recommended a new Phase 3 trial of its ovarian cancer drug mirvetuximab soravtansine.
The experimental antibody-drug conjugate (ADC) mirvetuximab soravtansine is being trialled in patients with high folate receptor (FR) alpha-positive, platinum-resistant ovarian cancer.
In March, Massachusetts-based biotech ImmunoGen reported that its 366 patient FORWARD I trial had failed to meet its primary endpoint of progression free survival.