Agenus to Present New Clinical Data on AGEN1181 at AACR 2021

• Clinical benefit in previously unresponsive tumors, including CRC, ovarian, and endometrial
• Confirmed responses in cold tumors as characterized by MSS
• No neuroendocrine toxicities or hypophysitis
• Registrational trials planned to commence in 2021

LEXINGTON, Mass., March 10, 2021 (GLOBE NEWSWIRE) — Agenus Inc. (NASDAQ: AGEN), an immuno-oncology company with an extensive pipeline of checkpoint antibodies, cell therapies, adjuvants, and vaccines designed to activate immune response to cancers and infections, today announced that two abstracts on AGEN1181, Agenus’ Fc-enhanced next-generation anti-CTLA-4 antibody, were accepted for presentation at the American Association for Cancer Research (AACR) Annual Meeting from April 10 – 15, 2021.

In a Phase 1/2 clinical study, AGEN1181 has shown responses in tumors previously unresponsive to immune therapies, including ovarian cancer and MSS endometrial and colorectal cancers. The AACR presentation will cover the most up to date data. AGEN1181 is active even in patients with the low affinity FcγRIIIA allele, a genetic polymorphism which makes them generally unresponsive to first generation anti-CTLA-4. Further, AGEN1181 has demonstrated the ability to deplete intratumoral Tregs. Tregs are immunosuppressive T cells, and their depletion can allow for an improved antitumor immune response. Importantly, AGEN1181 is active without the neuroendocrine toxicities or hypophysitis observed with first generation agents.

The data to be presented at AACR will showcase the optimal performance of AGEN1181 in preclinical models and in clinical trials. Preclinical data show that AGEN1181’s Fc enhancement allows it to engage the immune system even in cases of patients with the low affinity FcyRIIIA allele, which first-generation molecules do not do. These data also show that across all observed populations, AGEN1181 has increased efficacy over first-generation antibodies, and that combinations with multiple agents including checkpoint inhibitors such as anti-PD-1 and anti-TIGIT, iNKT-activating therapy, and adoptive T cell therapy, could further increase that efficacy.

In addition, clinical data to date provide evidence that these observations are being borne out in patients. Responses have been observed in patients with in the low-affinity FcyRIIIA allele. Further, AGEN1181 is the first anti-CTLA-4 to show intratumoral Treg depletion in the clinic.

AGEN1181 is currently advancing in a Phase 2 trial in colorectal cancer alone and in combination with balstilimab, Agenus’ anti-PD-1 antibody. As of February 9, Agenus has reported 6 confirmed objective clinical responses in its AGEN1181 Phase 1/2 trial and no complement-mediated toxicities.

Presentation Details:

Abstract title: Fc-enhanced anti-CTLA-4 antibody, AGEN1181: New mechanistic insights for potent antitumor immunity and combination potential in treatment-resistant solid tumors
Presenting author: Antoine Tanne, PhD

Abstract title: Characterization of the pharmacodynamic activity of AGEN1181, an Fc-enhanced CTLA-4 antibody, alone and in combination with the PD-1 antibody balstilimab
Presenting author: Irina Shapiro, PhD

About Agenus
Agenus is a clinical-stage immuno-oncology company focused on the discovery and development of therapies that engage the body’s immune system to fight cancer. The Company’s vision is to expand the patient populations benefiting from cancer immunotherapy by pursuing combination approaches that leverage a broad repertoire of antibody therapeutics, adoptive cell therapies (through its AgenTus Therapeutics subsidiary), and proprietary cancer vaccine platforms. The Company is equipped with a suite of antibody discovery platforms and a state-of-the-art GMP manufacturing facility with the capacity to support clinical programs. Agenus is headquartered in Lexington, MA. For more information, please visit www.agenusbio.com and our Twitter handle @agenus_bio. Information that may be important to investors will be routinely posted on our website and Twitter.

Forward-Looking Statements
This press release contains forward-looking statements that are made pursuant to the safe harbor provisions of the federal securities laws, including statements regarding clinical development plans and timelines, the therapeutic potential of AGEN1181 alone and in combination with other agents, as well as the anticipated presentation of updated clinical and preclinical data. These forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially. These risks and uncertainties include, among others, the factors described under the Risk Factors section of our most recent Quarterly Report on Form 10-Q or Annual Report on Form 10-K filed with the Securities and Exchange Commission. Agenus cautions investors not to place considerable reliance on the forward-looking statements contained in this release. These statements speak only as of the date of this press release, and Agenus undertakes no obligation to update or revise the statements, other than to the extent required by law. All forward-looking statements are expressly qualified in their entirety by this cautionary statement.

Contact
Agenus Investor Relations
Jan Medina, CFA
Agenus
781-674-4490
Jan.Medina@agenusbio.com

Agenus Media Relations
Kimberly Ha
KKH Advisors
917-291-5744
kimberly.ha@kkhadvisors.com