The First Cold Atmospheric Plasma Phase I Clinical Trial for the Treatment of Advanced Solid Tumors: A Novel Treatment Arm for Cancer

SIMPLE SUMMARY: It is estimated that 65% of solid tumor resections result in residual microscopic tumor cells at the surgical margin, which contributes to local recurrence and poor survival despite advancements in cancer therapies. Cold Atmospheric Plasma (CAP), a unique form of physical plasma, has emerged as a promising medical technology. Canady Helios Cold Plasma (CHCP) is a novel CAP device investigated in the first phase I clinical study with the primary goal of demonstrating safety. Promising findings demonstrated the device’s ability to control residual disease and improve patient survival. Ex vivo experiments on patient tissue samples showed CHCP-induced cancer cell death without harming normal cells. These results present CHCP as a safe and effective treatment in combination with surgery, providing a new avenue for controlling microscopic residual cancerous cells at the surgical margin. ABSTRACT: Local regional recurrence (LRR) remains the primary cause of treatment failure in solid tumors despite advancements in cancer therapies. Canady Helios Cold Plasma (CHCP) is a novel Cold Atmospheric Plasma device that generates an Electromagnetic Field and Reactive Oxygen and Nitrogen Species to induce cancer cell death. In the first FDA-approved Phase I trial (March 2020–April 2021), 20 patients with stage IV or recurrent solid tumors underwent surgical resection combined with intra-operative CHCP treatment. Safety was the primary endpoint; secondary endpoints were non-LRR, survival, cancer cell death, and the preservation of surrounding healthy tissue. CHCP did not impact intraoperative physiological data (p > 0.05) or cause any related adverse events. Overall response rates at 26 months for R0 and R0 with microscopic positive margin (R0-MPM) patients were 69% (95% CI, 19–40%) and 100% (95% CI, 100–100.0%), respectively. Survival rates for R0 (n = 7), R0-MPM (n = 5), R1 (n = 6), and R2 (n = 2) patients at 28 months were 86%, 40%, 67%, and 0%, respectively. The cumulative overall survival rate was 24% at 31 months (n = 20, 95% CI, 5.3–100.0). CHCP treatment combined with surgery is safe, selective towards cancer, and demonstrates exceptional LRR control in R0 and R0-MPM patients. (Clinical Trials identifier: NCT04267575).