Oncorena AB is banking on the specificity of orellanine for killing kidney cells anywhere in the body to prolong survival in patients with metastatic renal cell carcinoma. But the probable side effects mean the company will be challenged to show any survival benefit outweighs the drug's impact on quality of life and heath economics.

Oncorena's orellanine is a toxin derived from the Cortinarius genus of mushrooms. According to Executive Chairperson Sara Pellme, the molecule's potential use in RCC was discovered at the University of Gothenburg during a search for an antidote to the mushroom toxin.