U.S. drug developer ImmunoGen Inc said on Friday its experimental ovarian cancer drug failed to meet the main goal of a late-stage study, driving its shares more than 40 percent lower on Friday.

When compared with chemotherapy, ImmunoGen's mirvetuximab soravtansine did not significantly prevent the disease from worsening.

While the drug was tested as a standalone treatment in this instance, ImmunoGen is also evaluating it in combination with other therapies, as well as developing other drugs for different forms of cancer.

The company said it would examine the trial results further to evaluate the drug's potential as a standalone treatment.

ImmunoGen was in a "strong" financial position and would continue to develop its other cancer treatments, it added.

Shares of the company were last down 46 percent at $2.17 in early trade.