Elios Therapeutics Reports 24-Month Survival Data for Personalized Vaccine

NEW YORK – Elios Therapeutics reported 24-month survival data from a trial investigating its tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine in patients with advanced, resected melanoma.

In the 144-patient study, participants were randomized to receive either Elios' vaccine or placebo and followed to see whether the vaccine prevented melanoma recurrence. After 24 months, 62.9 percent of patients who had completed six months of vaccine treatment had disease-free survival versus 34.8 percent in the placebo arm, which marked a nearly 60 percent reduction in the relative risk of disease recurrence. In the intent-to-treat population, 38.5 percent of vaccine-treated patients experienced 24-month disease-free survival versus 27 percent in the placebo arm, which did not reach statistical significance.

Elios' lead vaccine is personalized in that it is made from a patient's blood and tumor, so that it contains the tumor's unique antigenic profile. Once the personalized vaccine is administered, it is designed to elicit an innate and adaptive immune response by activating T cells and priming the immune system to recognize and destroy cells with tumor-specific antigens and mutations. 

Based on previously reported efficacy and safety data, an independent data safety monitoring board recommended that the trial continue and get longer follow-up data on the impact of the vaccine on disease-free survival and overall survival. Elios said in a statement that it will continue to study patients for 36 months and report final disease-free and overall survival rates in June 2020. 

The data so far has shown the vaccine to be well tolerated, the firm reported, with 35.9 percent of vaccine-treated patients and 31.7 percent of placebo-treated patients experiencing an adverse event, most of which were not serious.

Elios CEO Buddy Long said in a statement that the company met with the FDA this month to discuss breakthrough therapy and regenerative medicine advance therapy designations for the vaccine. The firm will also meet with the agency to discuss the design of a registration Phase III study and the best regulatory pathway for the vaccine.