-- BPT958, a bifunctional PD-1 immunoconjugate with a masked IL-2 payload designed to be processed specifically in the tumor microenvironment -

--In preclinical models, BPT958 induces potent antitumor activity with minimal systemic activation -

BASEL, Switzerland and SAN DIEGO, Nov. 08, 2024 (GLOBE NEWSWIRE) -- Bright Peak Therapeutics, a clinical-stage biotechnology company focused on discovering and developing multifunctional immunotherapies for cancer, today announced the presentation of BPT958, a new investigational cancer immunotherapy agent at the 39th Annual Meeting of the Society for Immunotherapy of Cancer (SITC) being held on November 8-10, 2024, in Houston, TX.

BPT958 is designed to combine two key immuno-stimulatory mechanisms of action into a single molecule, including coordinated PD-1/PD-L1 checkpoint blockade in tandem with a tumor-targeted delivery of IL-2 to T cells within the tumor microenvironment (TME). Preclinical studies demonstrate that BPT958 induces potent, synergistic anti-tumor immune responses superior to PD-1 blockade alone, with activity in both PD-1-sensitive and PD-1-resistant tumor models.

“Here we introduce BPT958, a bifunctional PD1-IL2 immunoconjugate with an optimized and masked IL-2 payload”, said Dr. Jon Wigginton, President of Research and Development at Bright Peak. "We rationally designed our tumor-activated IL-2 payload with the intent of selectively targeting antigen-experienced PD-1⁺ T_eff cells in the tumor microenvironment. We believe that this approach ultimately could yield a more favorable safety profile and increased therapeutic window compared to non-masked IL-2 approaches, and leverage the potential for use of BPT958 alone or in combination with other therapeutics for patients with a range of cancers."

Details regarding the upcoming SITC abstract presentations are as follows:

November 9, 2024, 9:00 AM – 9:00 PM (EST)
Poster 1320: Identification of PD1-IL2_TAP – a PD-1 Blocking Immunoconjugate Harboring a Tumor-Activatable Masked IL-2 Payload Lacking Binding to IL2Rβ/CD122

Abstract Highlights

• Using its chemical conjugation platform, Bright Peak generated a structurally unique Tumor-Activated IL-2 Payload (IL2_TAP) masked by a protease-cleavable intramolecular loop preventing its binding to IL2Rb/CD122.
• Site-specific chemical conjugation of the IL2_TAP payload to an anti-PD-1 Ab generates the PD1-IL2_TAP immunoconjugate (BPT958).
• In vitro, masked BPT958 is inactive in the absence of PD-1 expression. In contrast, in PD1^HIGH cells, BPT958 exhibits moderate potency due to cis-signaling which is further enhanced following protease-mediated activation.
• In mice, PD1-IL2_TAP exhibits an Ab-like PK profile characterized by a long plasma half-life and sustained high exposure within the TME.
• BPT958 shows minor activity on NK and CD8+ T cells in the periphery while inducing a significant expansion of CD8+ Teff cells in the TME.
• In vivo, BPT958 exhibits a superior safety profile compared to non-masked PD1-IL2 translating into an increased therapeutic window in PD-1-sensitive as well PD-1-resistant tumor models.

About Bright Peak Therapeutics
Bright Peak Therapeutics is a clinical-stage biotechnology company pioneering multifunctional immunotherapies to treat cancer. Leveraging innovative protein engineering and a proprietary chemical protein synthesis and conjugation platform, Bright Peak is building a robust pipeline of first-in-class multifunctional molecules. The company's lead program, BPT567, is a bifunctional PD1-IL18 immunoconjugate currently in Phase 1/2a clinical trials. With headquarters in Basel, Switzerland, and San Diego, CA, Bright Peak is backed by top-tier healthcare investors. For more information, visit www.brightpeaktx.com.

Contact:
info@brightpeaktx.com