Personalized Cancer Vaccine Shows Long-Term Survival for Patients with High-Risk Melanoma

Final data was announced from a prospective, randomized, double-blind, placebo-controlled Phase 2b clinical trial that examined adjuvant use of a personalized tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine for patients with stage III or IV melanoma at high risk of recurrence, according to a press release from Elios Therapeutics.

The long-term data found a correlation of a 93% increase in patients alive at 3 years without disease recurrence with treatment for high risk melanoma with the TLPLDC vaccine.

"These new data, combined with the doubled rate of disease-free survival among patients treated with the vaccine and standard of care checkpoint inhibitors, further strengthen our confidence that the personalized TLPLDC vaccine provides a clinically meaningful benefit for people with high-risk melanoma,” Buddy Long, chief executive officer of Elios Therapeutics, said in a press release. “We look forward to advancing this vaccine with a registrational Phase III trial that will move us one step closer to bringing this important treatment to patients as soon as possible."

The researchers analyzed 2 versions of the vaccine in 144 patients who were randomized to receive either version of the vaccine or a placebo. Vaccine-A was produced by isolating dendritic cells (DCs) from 120 mL of blood while vaccine-B with DCs isolated after a single injection of filgrastim followed by 50-70 mL of blood.

The data found that treatment with vaccine-B was similar to treatment with a placebo. Vaccine-B was rendered ineffective because of the 72-hour time period it takes to produce the vaccine with filgratism (Neupogen), which was intended to increase white blood cell and dendritic cell counts.

"To demonstrate a long-term survival benefit with low toxicity in a therapeutic is what we hope for in every clinical trial. Achieving this with an aggressive disease like melanoma offers great promise for patients," Mark B. Faries, MD, principal investigator of the study, said in the release.

Overall, vaccine-A when compared to vaccine-B and placebo saw a statistically significant improvement in 36-month disease-free survival (DFS, 51.8% vs. 23.4% vs 27.1%, respectively; P= .027) and overall survival (92.9% vs. 62.8% vs 70.3%, respectively; P= .022).

More, vaccine-A saw a DFS improvement across both patients with stage III (49.7% vs. 29.4%; P= .066) and stage IV (68.6% vs. 9.4%; P= .0582) disease. Vaccine-A, when added to standard of care checkpoint inhibitors, led to a statistically significant increase in DFS compared to checkpoint inhibitors alone (48.5% vs. 24.1%; P= .039).

The vaccine is composed of a patient’s own blood and tumor cells, with samples collected at resection, frozen, and then used to create autologous tumor lysate. This combination is introduced to a patient’s dendritic cells, resulting in the finished TLPLDC vaccine.

"With data showing a two-fold increase in disease-free survival with the vaccine alone and in combination with checkpoint inhibitors, we hope to one day change the narrative for people with melanoma - turning this disease into a chronic condition that can be treated and managed over time," Faries said.

Reference:

Elios Therapeutics Personalized Cancer Vaccine Demonstrates Long-Term Survival Benefit Among High-Risk Melanoma Patients in Phase IIb Final Analysis [news release]. Austin, Texas. Published August 5, 2020. https://www.prnewswire.com/news-releases/elios-therapeutics-personalized-cancer-vaccine-demonstrates-long-term-survival-benefit-among-high-risk-melanoma-patients-in-phase-iib-final-analysis-301106313.html. Accessed August 6, 2020.