Bright Peak Therapeutics Unveils New Data at 2024 SITC Annual Meeting

Bright Peak Therapeutics, a biotech company at the clinical stage focusing on developing multifunctional immunotherapies for cancer, unveiled BPT958, an investigational cancer immunotherapy agent. This announcement was made at the 39th Annual Meeting of the Society for Immunotherapy of Cancer (SITC) held in Houston, TX.

BPT958 is engineered to merge two critical immuno-stimulatory actions within a single molecule. It includes a coordinated blockade of the PD-1/PD-L1 checkpoint along with a tumor-targeted delivery of IL-2 to T cells present in the tumor microenvironment (TME). Preclinical studies have revealed that BPT958 triggers strong, synergistic anti-tumor immune responses that surpass the efficacy of PD-1 blockade alone. It shows activity in both PD-1-sensitive and PD-1-resistant tumor models.

Dr. Jon Wigginton, President of Research and Development at Bright Peak, explained, "We introduce BPT958, a bifunctional PD1-IL2 immunoconjugate with an optimized and masked IL-2 payload." This innovative design aims to selectively target antigen-experienced PD-1+ T effector cells within the TME, potentially offering a safer profile and a wider therapeutic window compared to non-masked IL-2 approaches. This method may allow BPT958 to be used alone or alongside other treatments for various cancers.

Key details about the SITC abstract presentations include:

On November 9, 2024, from 9:00 AM to 9:00 PM (EST), Poster 1320 will be presented, highlighting the identification of PD1-IL2TAP. This is a PD-1 blocking immunoconjugate featuring a tumor-activatable masked IL-2 payload that does not bind to IL2Rβ/CD122.

The abstract presentation will cover several highlights:

- Utilizing its chemical conjugation platform, Bright Peak developed a unique Tumor-Activated IL-2 Payload (IL2TAP), masked by a protease-cleavable intramolecular loop to prevent binding to IL2Rb/CD122.
- The site-specific chemical conjugation of the IL2TAP payload to an anti-PD-1 antibody creates the PD1-IL2TAP immunoconjugate, known as BPT958.
- In vitro studies show that masked BPT958 remains inactive without PD-1 expression. However, in PD1HIGH cells, BPT958 exhibits moderate potency through cis-signaling, which is further enhanced after protease-mediated activation.
- In mice, PD1-IL2TAP displays an antibody-like pharmacokinetic profile with a long plasma half-life and sustained high exposure within the TME.
- BPT958 has minimal activity on NK and CD8+ T cells in the periphery but significantly expands CD8+ T effector cells in the TME.
- In vivo, BPT958 demonstrates a superior safety profile compared to non-masked PD1-IL2, translating into an increased therapeutic window in both PD-1-sensitive and PD-1-resistant tumor models.

Bright Peak Therapeutics, with headquarters in Basel, Switzerland, and San Diego, CA, is a clinical-stage biotechnology company that pioneers multifunctional immunotherapies for treating cancer. Utilizing innovative protein engineering and a proprietary chemical protein synthesis and conjugation platform, Bright Peak is developing a robust pipeline of first-in-class multifunctional molecules. Their leading program, BPT567, is a bifunctional PD1-IL18 immunoconjugate currently undergoing Phase 1/2a clinical trials. The company is supported by top-tier healthcare investors.