Enlivex Therapeutics Ltd., a clinical-stage macrophage reprogramming immunotherapy company, entered into a clinical collaboration with BeiGene to evaluate the safety and efficacy of Allocetra, an investigational macrophage-reprogramming cell therapy, in combination with tislelizumab, an anti-PD-1 immune checkpoint inhibitor, for the treatment of patients with advanced-stage solid tumors.

“We are excited to explore the potential of Allocetra in combination with tislelizumab, a potentially differentiated PD-1 inhibitor,” said Shai Novik, executive chairman of Enlivex. “We look forward to integrating tislelizumab into our ongoing Phase I/II clinical trial.”

Oren Hershkovitz, CEO of Enlivex said: “Combinatorial approaches for fighting difficult-to-treat cancers historically have proven to be important in the delivery of better treatments to patients. We believe that the preclinical data observed to date for Allocetra, with its unique macrophage-modulation properties, and immune checkpoints, support the evaluation of the combination for the treatment of patients with the tislelizumab-Allocetra combinations.”

Under the agreement, Enlivex has agreed to amend its ongoing Phase I/II trial in patients with advanced-stage solid tumors to include evaluation of Allocetra in combination with tislelizumab. The Phase I/II trial is a multicenter, open-label, dose escalation trial that is expected to enroll up to 48 patients with advanced solid tumors across two trial stages.

Stage 1 of the trial will examine escalating doses of Allocetra monotherapy administered intravenously (IV) or intraperitoneally (IP) once a week for three consecutive weeks.

Meanwhile, Stage 2 will evaluate escalating doses of Allocetra administered IV or IP and combined with anti-PD1 therapy. BeiGene will provide the clinical supply of tislelizumab for the trial.