152P - Discovery of best-in-class dual-acting A2AR/A2BR antagonists that are functional in high adenosine environment

Background

Adenosine accumulates in the tumor microenvironment due to abnormal tumor metabolism and hypoxia. It binds to A_2A and A_2B receptors on immune cells and impairs their activation and cytotoxic ability, helping cancers to evade the immune system and resist cancer therapies. Adenosine receptor antagonists that act in pathological concentrations of adenosine can rescue T cell and innate immune suppression and improve the efficacy of existing treatments.

Methods

We used structure-guided medicinal chemistry to design adenosine antagonists and measured how well they bind to A_2A and A_2B receptors in cells using HTRF and Tag-lite technology. Their ability to block adenosine’s effect on primary immune cells was monitored by measuring CREB phosphorylation and cytokine production. In vitro coculture assays and syngeneic mouse models were used to check the effect of immune response and tumor growth. We also used a patient-derived ex vivo tumor platform to demonstrate clinical translatability.

Results

BWC2094 is a potent A2A receptor antagonist, while BWC2562 is a potent A2A/A2B dual antagonist in a high adenosine environment. They selectively bind A2A at picomolar concentrations and had >50-fold selectivity over A1 and A3 receptors. They reduced the phosphorylation of CREB and restored the production of cytokines, such as IL2, TNFα and IFNγ in adenosine-suppressed immune cells. The lead compounds exhibited a synergistic effect with standard of care drugs in co-culture assays of tumor cells and PBMC. Both, BWC2094 and BWC2562 demonstrated good oral bioavailability in rodents (>25 %F) and dogs (>50 %F) and are well tolerated for 14 days in rat acute toxicity study. At a dose of 3mg/kg, they reduce the tumor volume as monotherapy and enhanced the anti-tumor effects of anti-PD1/PDL1 and CTLA4 in CT26, MC38, and MCA205 murine tumor models. In a patient-derived ex vivo tumor model, Precision immunotherapy using Complementary approaches in Systems Oncology (PiCaSO), they reduced tumor density, decreased Ki67 expression and increased apoptosis/necrosis.

Conclusions

BWC2094 and BWC2562 can block the immunosuppressive effects of adenosine and improve the effectiveness of existing therapies in oncology.

Legal entity responsible for the study

The authors.

Funding

Bugworks Research Inc.

Disclosure

N. Katagihallimath, R. Nandishaiah, S. Sharma, S. Venkatesan, R. Rao, N. Bharatham, M. Gupta, D. Kundu, H. Kaushik Kotakonda, R. Ramalingam Kalainesan, S. Reddy, B. Tewary, L. Maitreyi, B. Venkatraman, S. V Rekha Sody, B. Majumder: Financial Interests, Personal and Institutional, Stocks/Shares: Bugworks. S. Datta, S.Hameed: Financial Interests, Personal and Institutional, Stocks or ownership: Bugworks. All other authors have declared no conflicts of interest.