ImmunoGen's Elahere delivers positive results in ovarian cancer trial, stock soars.

ImmunoGen's experimental ovarian cancer drug, Elahere, helped extend the lives of patients and significantly prolonged the time that a patient lives without the cancer worsening, according to a late-stage trial. The US FDA had earlier given accelerated approval for Elahere, based on data from a single-arm trial. The company plans to submit a marketing application in Europe and a supplemental application in the US for the conversion to a regular approval by the second half of the year. Shares of the drug developer jumped to a near five-year high of $11.95 on Wednesday.