Data demonstrates that PTX-35 may have utility in solid organ transplantation, and to potentially slow or mitigate deleterious immune responses where self-tissue tolerance is impaired

DURHAM, NC, USA I January 12, 2022 I Heat Biologics, Inc. (“Heat”) (NASDAQ: HTBX), a clinical-stage biopharmaceutical company focused on developing first-in-class therapies to modulate the immune system, today announced promising new preclinical data regarding PTX-35 has been accepted for publication in the American Journal of Transplantation and is available at:

Key Findings:

  • A single dose of the preclinical version of PTX-35 (mPTX-35), was able to expand regulatory T cells (Tregs) and significantly improve disease and graft survival outcomes.
  • Chemically induced pancreatic failure (a model for type-1 diabetes) could be partially reversed when mice were transplanted with beta-cell islet allografts and treated with mPTX-35.
  • Disease protection in preclinical models was correlated with a significant expansion of Tregs and protection of the allograft, resulting in euglycemia and a graft survival benefit.
  • Long-term surviving grafts showed a marked increase in Treg infiltration which directly correlated with mPTX-35 agonist activity.  

PTX-35 is a novel, potential first-in-class antibody immunomodulator of TNFRSF25 (death receptor 3), a receptor that is preferentially expressed by antigen-experienced T cells and can be manipulated to expand regulatory T-cell subsets. PTX-35 is the Company’s first antibody-based product, currently in a Phase 1 clinical trial for the treatment of patients with solid tumors.

Dr. James Shapiro, Professor in the Department of Surgery and Clinical Islet Transplant Program at the University of Alberta, Edmonton, Canada, commented, “The study demonstrated that a single dose of PTX-35 enabled prolonged graft survival in a mouse model of pancreatic islet allotransplantation. Additionally, PTX-35 could contribute to achieving lasting immunological tolerance in organ transplantation.”

Jeff Wolf, Chief Executive Officer of Heat, commented, “We are very encouraged by these results showing pronounced Treg expansion and significantly prolonged graft survival compared to control. PTX-35 has the potential to modulate immunological responses and may facilitate minimization of post-transplant immunosuppression, which supports further clinical evaluation in the context of inflammatory disease. Similar preclinical results have also been previously demonstrated for bone marrow, corneal and cardiac transplantation using these and other TNFRSF25 agonists.”

Mr. Wolf further noted, “We are also making significant progress with HS-110 and expect to file for an End of Phase 2 meeting with the FDA this quarter. Our goal for this meeting is to discuss potential Phase 3 registration pathways for HS-110. Although this submission is taking longer than expected, we believe we have prepared a very comprehensive package and look forward to the FDA’s feedback.”

About Heat Biologics, Inc.
Heat Biologics is a biopharmaceutical company focused on developing first-in-class therapies and vaccines to modulate the immune system. Heat’s gp96 platform is designed to activate immune responses against cancer or infectious diseases. The Company has multiple product candidates in development leveraging the gp96 platform, including HS-110, which has completed enrollment in a Phase 2 trial, various infectious disease/biological threat programs in preclinical development and a pipeline of proprietary immunomodulatory antibodies and cell-based therapies, including PTX-35 and HS-130 in Phase 1 clinical trials.

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SOURCE: Heat Biologics