Safety concerns regarding Kite Pharma Inc.’s cancer treatments have dogged the Santa Monica biotech firm on Wall Street over the past year, contributing to the firm’s 20 percent stock price decline during the last 12 months.

Yet the company’s founder and chief executive, Arie Belldegrun, told Forbes that the cancer-killing immune cell treatments are the start of a “revolution” in oncology, despite the fact that a patient in one of its clinical trials died.

Despite the setback, immune therapy treatments developed by Kite and competitors such as Novartis and Juno Therapeutics have had positive results in early clinical trials, making previously untreatable tumors melt away.

However, they have been found in other cases to overstimulate the immune system, sometimes causing a toxic reaction in patients.

The safety of Kite’s experimental chimeric antigen receptor T-cells (CARTs) will be top-of-mind for investors as the Santa Monica firm prepares to announce its quarterly results on February 29 after the market closes.