Gritstone (GRTS) Plummets 58% in a Week: Here's Why

Gritstone Bio (GRTS) is a clinical-stage biotechnology company focused on developing vaccines targeting multiple indications, including cancer.In the past week, the company’s stock lost 57.5%. This downside came after management came out with preliminary results from the mid-stage portion of the phase II/III study on its investigational personalized cancer vaccine (PCV), Granite.The phase II/III study evaluated the combination of Granite as a maintenance therapy in patients with metastatic microsatellite st ...