Disc Medicine Plummets After Placebo Effect Confounds Sunlight Sensitivity Study

Disc Medicine's (IRON) light sensitivity treatment succeeded in a midstage study Monday, but an outsize placebo response confounded the results and the biotech stock plummeted.

The biotech company is trying to treat erythropoietic protoporphyria, a rare condition in which a toxic metabolite called protoporphyrin IX builds up in the blood.