About the 5 percent drop in overall response rate (ORR) in the expanded phase I trial with the company’s antibody-drug conjugate (ADC) for ovarian cancer, Immunogen Inc.’s chief development officer, Charles Morris, said he was “not sure I’d call it significant,” as the company made known its plan to switch its Forward 1, two-stage phase II experiment to a single-stage phase III study without blessings from the FDA – an idea that made some analysts leery.