Agenus to Present at the American Society of Clinical Oncology 2023 Annual Meeting

April 26, 2023 at 10:35 AM EDT

Oral presentation on Phase 2 trial evaluating balstilimab/zalifrelimab plus standard of care in advanced sarcoma
Poster discussion on Phase 1 trial investigating AGEN2373 monotherapy in advanced solid tumors

Agenus (Nasdaq: AGEN), a leading immuno-oncology company specializing in immunological agents for cancer and infectious diseases, today announced plans to present clinical data at the American Society of Clinical Oncology (ASCO) 2023 Annual Meeting, to be held June 2-6 in Chicago, IL.

Data from a single-arm, open-label Phase 2 study of balstilimab (PD-1 antagonist) and zalifrelimab (first generation CTLA-4 antagonist) plus doxorubicin in patients with advanced sarcomas will be presented at an oral session on Monday, June 5 from 11:30am - 2:30pm CDT.

Complete results from the monotherapy arm of the first-in-human dose escalation study of AGEN2373 (CD137 agonist) in patients with advanced solid tumors will be presented at a poster discussion on Saturday, June 3^rd from 3:00pm - 4:30pm CDT.

Presentation Details:

Abstract Title: A single-arm, open-label phase 2 trial of doxorubicin plus zalifrelimab, a CTLA-4 inhibitor, with balstilimab, a PD-1 inhibitor, in patients with advanced/metastatic soft tissue sarcomas

Abstract #: 403784

Presenting Author: Dr. Breelyn Wilky, MD, Director of Sarcoma Medical Oncology, Deputy Associate Director for Clinical Research, University of Colorado Medicine

Session Title: Oral Abstract Session - Sarcoma

Session Date and Time: 6/5/2023, 11:30am – 2:30pm CDT

Abstract Title: A Phase 1 Study of AGEN2373, a Novel CD137 Agonist Antibody Designed to Avoid Hepatoxicity, in Patients with Advanced Solid Tumors (NCT 04121676)

Abstract #: 2524

Poster Board #: 366

Presenting Author: Dr. Minal Barve, MD, Executive Medical Director and Chief Medical Officer, Mary Crowley Cancer Research

Poster Discussion Session: Developmental Therapeutics - Immunotherapy

Poster Session Display Date and Time: 6/3/2023, 8:00am – 11:00am CDT

Poster Discussion Session Date and Time: 6/3/2023, 3:00pm – 4:30pm CDT

The complete abstracts will be available on May 25^th, 2023, at 5:00pm ET. Data presented at the conference will be available to view in the Publications section of the Agenus website (https://agenusbio.com/publications) following the ASCO Conference.

About Balstilimab

Balstilimab is a novel, fully human monoclonal immunoglobulin G4 (IgG4) designed to block PD-1 (programmed cell death protein 1) from interacting with its ligands PD-L1 and PD-L2. PD-1 is a negative regulator of immune activation that is considered a foundational target within the immuno-oncology market. Agenus is developing balstilimab as a backbone agent for combination trials within its portfolio, as well as supplying drug to collaborators to enable novel combinations with external agents.

About Zalifrelimab

Zalifrelimab is a novel, fully human monoclonal immunoglobulin G1 (IgG1) designed to block CTLA-4 (cytotoxic T-lymphocyte associated antigen 4) from interacting with its ligands CD80 and CD86. Clinical trials have shown its efficacy in multiple indications, including a Phase 2 study in cervical cancer where it demonstrated robust activity in combination with balstilimab (O’Malley et al. JCO 2022).

About AGEN2373

AGEN2373 is a novel anti-CD137 agonist that has been designed to activate T and NK cells while mitigating liver toxicities common to the CD137 target class. CD137 (4-1BB) is an activating receptor expressed on T and NK cells. Upon binding to CD137, AGEN2373 is designed to stimulate the growth and activation of cytotoxic T and NK cells, triggering a lasting memory response to cancer. AGEN2373 binds to a unique epitope designed to achieve this response specifically within the tumor microenvironment. This selective binding is designed to avoid serious side effects associated with CD137 activation in the liver that have been reported by competitor molecules. AGEN2373 has demonstrated preliminary clinical activity and has been well tolerated by patients without signs of liver toxicity (Tolcher et al. ASCO 2021).

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 and infections. 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 subsidiary MiNK Therapeutics), and adjuvants (through its subsidiary SaponiQx). 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 relating to the use of AGEN2373, for instance, statements regarding therapeutic benefit and efficacy, mechanism of action (including validation of mechanism of action), potency, durability, and safety profile (including the absence of specific toxicities) of the Company’s therapeutic candidates; and any other statements containing the words "may," "believes," "expects," "anticipates," "hopes," "intends," "plans," "forecasts," "estimates," "will," “establish,” “potential,” “superiority,” “best in class,” and similar expressions are intended to identify forward-looking statements. 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.