Investing.com -- Erasca Inc. shares fell as much as 55% on Tuesday after the cancer-drug developer disclosed that a patient died following severe side effects from its experimental treatment.

The San Diego-based company said a 66-year-old man went to the emergency room with severe lung inflammation about a month after beginning the therapy. The patient withdrew from the clinical trial and later died after stopping the treatment.

Erasca released the information alongside data from an early-stage trial of its experimental therapy for pancreatic and lung cancer. The company said the treatment was generally well-tolerated with mostly low-grade side events.