Shares of cancer treatment producer ImmunoGen (IMGN) - Get Report plunged more than 30% on Wednesday after the company revealed that the U.S. Food and Drug Administration  has recommended further trials to "evaluate the safety and efficacy" of one of its cancer-fighting treatments.

ImmunoGen said in statement that it had requested a meeting with FDA officials to discuss the results of its Phase 3 FORWARD I trial and a potential path to registration for mirvetuximab monotherapy - a treatment it has been developing for patients with certain forms of ovarian cancer.

In response, the FDA told ImmunoGen that because the data results produced to date have not been able to meet expectations, "... the study could not be used to support an application for accelerated approval," ImmunoGen said in a statement.

"Our meeting with FDA enabled us to clarify a regulatory path forward for mirvetuximab and we are evaluating all avenues to bring this promising therapy to ovarian cancer patients," ImmunoGen CEO Mark Enyedy said in the statement.

Separately, ImmunoGen said it is conducting an operational review of its business, with the objective of extending the company's cash runway to continue its research and development of mirvetuximab and other therapy treatments.

Shares of ImmunoGen were down 29%, or 90 cents, at $2.25 in early trading on Wednesday. They ended the day Tuesday down 1.94% at $3.15.