Elios Therapeutics has reported positive findings from a Phase IIb clinical trial of its investigational TLPLDC vaccine in stage III and IV resected melanoma patients.

The tumour lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is a personalised immunotherapy formulated using a patient’s tumour and blood.

The therapeutic is intended to trigger a dual innate and adaptive immune response with the activation of T cells, stimulating the immune system to kill cells containing antigens and tumour mutations.

TLPLDC was compared to placebo in a total of 144 patients during the study.

The primary endpoint of the prospective, randomised, double-blind, placebo-controlled trial is two-year disease-free survival (DFS), while secondary endpoints include DFS at 36 months and overall survival.

According to the top-line data, the primary endpoint was met with a statistically significant decrease in the risk of disease recurrence at 24 months in the per treatment (PT) population.

Primary analysis revealed a 29% recurrence rate in the vaccine group of the population, compared to 56% in the placebo arm. This demonstrates a statistically significant 50% reduction in the relative disease recurrence risk.

However, analysis of the PT and intent-to-treat (ITT) populations revealed an 18% clinically meaningful, but statistically non-significant, decrease in the relative risk.

Safety analysis found that one-third of participants experienced a related adverse event (AE).

Data from a 36-month follow-up of all patients showed durable vaccine benefit that sustained beyond 24 months.

Based on these positive findings, the Phase IIb trial will continue to the 36-month endpoints of DFS and overall survival. These results are expected to be available in June next year.

Elios Therapeutics CEO Buddy Long said: “This is the first positive Phase IIb study of a personalised cancer vaccine in patients with high-risk melanoma, an aggressive disease with a need for safer and more effective treatment options.

“We believe the results from this trial support advancing the TLPLDC clinical programme to a Phase III trial.”