Shares of GTx Inc. plunged Monday after the drug developer said its potential treatment for muscle wasting in lung cancer patients fell short of some main goals in late-stage clinical testing.
The Memphis, Tenn., company said enobosarm failed to meet overall criteria for lean body mass and physical function that it had agreed to with the Food and Drug Administration.
The company's shares sank 64 percent, or $2.66, to $1.49 in Monday morning trading. That put the stock down about 65 percent so far this year.
The company is studying enobosarm in patients with advanced forms of non-small cell lung cancer. There are no drugs approved to prevent or treat muscle wasting in cancer patients. GTx said cancer-induced muscle wasting leads to fatigue and weight loss, which can contribute to a shorter overall survival time.
In January, GTx had said that the FDA would review enobosarm under its fast-track program, which is designed to speed up the approval of drugs that treat serious or life-threatening diseases for which there are few other therapies.
GTx said Monday it would talk to both the FDA and European regulators about the next step forward for the drug.
It said enobosarm did have a consistent effect on lean body mass when compared with a placebo. CEO Dr. Mitchell Steiner said in a statement that the company was confident the drug will provide a clinical benefit and possibly increase patient survival.
GTx focuses on developing treatments for cancer, cancer supportive care and other serious medical conditions.