Agenus' New Sarcoma Treatment Presents Promising Results at ESMO Congress 2023

Agenus Inc. presented promising data at the ESMO Congress 2023, showing the effectiveness of their botensilimab and balstilimab combination in treating advanced sarcomas. The treatment yielded a 40% 6-month progression-free survival rate and responses lasting over a year in certain cases.

Agenus Inc., a pioneering firm in the development of innovative immunotherapies for cancer, has unveiled new data indicating promising outcomes for its combination treatment for advanced sarcomas. The study involving 41 patients revealed manageable side effects and no new safety concerns. The findings were shared at the European Society for Medical Oncology (ESMO) Congress 2023.

Agenus announced expanded data from the company's Phase 1b study of botensilimab (BOT, a multifunctional immune activator) in combination with balstilimab (BAL, anti-PD-1) for patients with advanced sarcomas.

Sarcoma, particularly in its advanced stages, remains a challenging cancer to treat. Current treatments offer only limited effectiveness, underscoring the urgent need for more potent therapies.  This amplifies the significance of Agenus' phase 1b study, which is exploring the potential of botensilimab (BOT), a multifunctional immune activator, used alone and in combination with balstilimab (BAL), an anti-PD-1 agent.

Dr. Steven O’Day, Chief Medical Officer of Agenus, highlighted the encouraging outcomes, 

"These results reinforce the promising potential of BOT+BAL in multiple cold, treatment-resistant solid tumors. Notably, we observed several durable responses extending past one year, including patients with visceral angiosarcoma, which is traditionally unresponsive to immunotherapy, as well as other cold subtypes like leiomyosarcoma. As we expand the study, we aim to focus on key subsets and dosing strategies to maximize benefit for patients.”

Dr. Breelyn Wilky, MD, Director of Sarcoma Medical Oncology at the University of Colorado, reinforced this optimism, revealing that

“As the study has advanced, BOT+BAL continues to demonstrate encouraging results in a larger population of patients with difficult to treat sarcomas, with a median response duration of 19.4 months and a 40% 6-month progression-free survival rate. We're also seeing a dose-dependent effect, with a 29% objective response rate at 2 mg/kg.”

Key insights from the study:

• Patient Profile: The study involved 41 patients, primarily diagnosed with either angiosarcoma (29%) or leiomyosarcoma (39%). Most had undergone multiple treatments, averaging three prior therapy lines.
• Efficacy: The overall response rate (ORR) was 20%, with a 29% ORR at the 2 mg/kg dose of BOT and a 15% ORR at the 1 mg/kg dose. Additionally, a 63% disease control rate was observed.
• Safety: Out of 50 patients, no new safety concerns emerged. Adverse effects were generally controllable and reversible. Diarrhea/colitis was the primary immune-related side effect, but there were no reported severe treatment-linked adverse events or irreversible conditions such as hypophysitis or myocarditis.
• These findings provide a glimmer of hope for patients with advanced sarcomas, marking a potential stride forward in the battle against this formidable disease.