PTX-35 represents a potential first-in-class agonistic antibody of TNFRSF25

DURHAM, NC, USA I June 8, 2020 I Heat Biologics, Inc. (“Heat”) (NASDAQ:HTBX), a clinical-stage biopharmaceutical company focused on developing first-in-class therapies to modulate the immune system, including multiple oncology product candidates and a novel COVID-19 vaccine, today announced that the U.S. Food & Drug Administration (FDA) has cleared the Investigational New Drug (IND) application for PTX-35, developed by Heat’s Pelican Therapeutics subsidiary. Pelican has near-term plans to initiate its Phase 1 clinical trial in patients with solid tumors.

PTX-35 is a novel, first-in-class agonist antibody targeting TNFRSF25, also known as death receptor 3 (DR3), a receptor that is preferentially expressed by antigen-experienced T cells. TNFRSF25 agonism leads to activation of antigen-experienced memory CD8+ T cells, which are instrumental for tumor destruction. Preclinical studies have demonstrated PTX-35, in combination with antigen-driven immunotherapies, resulted in enhanced anti-tumor properties, including potent proliferation of antigen-specific T cells, production of effector cytokines and augmented effector immune function.

Rahul Jasuja, PhD, CEO of Pelican Therapeutics, commented, “The mechanism of action for PTX-35 is highly differentiated compared to other co-stimulators. Activation of TNFRSF25 by PTX-35 in preclinical models leads to a more pronounced expansion of tumor antigen-specific cytotoxic, or “killer” T cells, resulting in enhanced tumor growth inhibition and prolonged survival. The team has delivered a robust IND package, demonstrating pre-clinical efficacy along with a favorable safety profile in mice and non-human primates.”

Jeff Wolf, CEO of Heat, said, “PTX-35 is a potential first-in-class therapy that may provide additional treatment options for cancer patients. We are close to initiating our first-in-human clinical trial of PTX-35 in multiple solid tumors and look forward to providing further updates as we achieve anticipated milestones. We would like to thank Cancer Prevention Research Institute of Texas (CPRIT) for the $15.2 million grant to support the preclinical work, cGMP manufacturing and Phase 1 development of PTX-35.”

About Heat Biologics, Inc.

Heat Biologics is a biopharmaceutical company focused on developing first-in-class therapies to modulate the immune system. The company’s gp96 platform is designed to activate immune responses against cancer or pathogenic antigens. Multiple product candidates in development leveraging the gp96 platform, including HS-110 in phase 2, HS-130 in phase 1, and COVID-19 vaccine program in preclinical development. In addition, Heat Biologics is also developing a pipeline of proprietary immunomodulatory antibodies, including PTX-35. For more information, please visit

SOURCE: Heat Biologics