1. L-DOS47 Elevates Pancreatic Cancer Tumor pH and Enhances Response to Immunotherapy
- Author
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Bruna Victorasso Jardim-Perassi, Pietro Irrera, Oluwaseyi E. Oluwatola, Dominique Abrahams, Veronica C. Estrella, Bryce Ordway, Samantha R. Byrne, Andrew A. Ojeda, Christopher J. Whelan, Jongphil Kim, Matthew S. Beatty, Sultan Damgaci-Erturk, Dario Livio Longo, Kim J. Gaspar, Gabrielle M. Siegers, Barbara A. Centeno, Justin Y. C. Lau, Shari A. Pilon-Thomas, Arig Ibrahim-Hashim, and Robert J. Gillies
- Subjects
pancreatic cancer ,targeted therapy ,L-DOS47 ,acidosis ,immunotherapy ,Biology (General) ,QH301-705.5 - Abstract
Acidosis is an important immunosuppressive mechanism that leads to tumor growth. Therefore, we investigated the neutralization of tumor acidity to improve immunotherapy response. L-DOS47, a new targeted urease immunoconjugate designed to neutralize tumor acidity, has been well tolerated in phase I/IIa trials. L-DOS47 binds to CEACAM6, a cell-surface protein that is highly expressed in gastrointestinal cancers, allowing urease to cleave endogenous urea into two NH4+ and one CO2, thereby raising local pH. To test the synergetic effect of neutralizing tumor acidity with immunotherapy, we developed a pancreatic orthotopic murine tumor model (KPC961) expressing human CEACAM6. Using chemical exchange saturation transfer–magnetic resonance imaging (CEST-MRI) to measure the tumor extracellular pH (pHe), we confirmed that L-DOS47 raises the tumor pHe from 4 h to 96 h post injection in acidic tumors (average increase of 0.13 units). Additional studies showed that combining L-DOS47 with anti-PD1 significantly increases the efficacy of the anti-PD1 monotherapy, reducing tumor growth for up to 4 weeks.
- Published
- 2024
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