ImmunoGen Inc. (NASDAQ:IMGN) said Wednesday that its small-cell lung cancer SCLC treatment has been granted orphan drug designation by the Food and Drug Administration.

The biotechnology company, which develops antibody-based targeted anticancer products, received the designation for its lorvotuzumab mertansine, an investigational agent designed to kill cancer cells that express CD56, a protein.

Through a separate process, the company’s drug has been recognized as an orphan medicinal product for the treatment of SCLS from the European Medicines Agency Committee for Orphan Medicinal Products, and is awaiting final designation from the European Commission.

The compound was previously granted orphan drug designation for the treatment of Merkel cell carcinoma in both the US and EU.

“Lorvotuzumab mertansine has shown encouraging initial activity and tolerability when used as a single agent to treat relapsed SCLC, a very difficult cancer,” said ImmunoGen CEO Daniel Junius. “We believe this product candidate has the potential to make a real difference for patients with SCLC, and we’re planning to start a trial later this year that assesses the compound, used together with standard care, for first-line treatment of this cancer.”

The orphan designation targets drugs that treat rare diseases, or fewer than 200,000 Americans.

It provides the drug with fast-tracked FDA approval and seven years of market exclusivity once it receives marketing approval for the treatment of SCLC.

The similar designation in the EU is intended to encourages companies to develop therapies for life-threatening or chronically debilitating conditions that affect no more than five in 10,000 people.