Agenus to Present First Phase 2 Botensilimab Data in Advanced Cutaneous Melanoma at ASCO 2026

Key Terms

phase 2 medical

Phase 2 is the mid-stage clinical trial where a new drug or treatment is tested in a larger group of patients to see if it works and to keep checking safety after initial human testing. Think of it as a field test that proves whether a product actually delivers its promised benefit. Investors watch Phase 2 closely because its results strongly influence a medicine’s chances of reaching the market, the size of its potential sales, and the company’s valuation.

phase 3 medical

Phase 3 is the late-stage clinical testing step for a new drug or medical treatment, where the product is given to large groups of patients to confirm effectiveness, monitor side effects, and compare it to standard care. Successful Phase 3 results are often the final scientific hurdle before regulators decide on approval and market launch—like passing a final exam before graduation—and can sharply change a company's valuation and future revenue prospects.

ctla-4 medical

CTLA-4 is a protein on certain immune cells that acts like a brake, helping to slow or stop immune responses. Drugs that block CTLA-4 release that brake and can boost the immune system’s ability to attack cancer, but they can also increase the risk of immune side effects. For investors, CTLA-4 is important because it’s a proven drug target with major commercial and regulatory implications for cancer therapies and related safety profiles.

anti–pd-(l)1 medical

Anti–PD-(L)1 therapies are drugs—usually lab-made antibodies—that block a “brake” interaction between a protein on immune cells (PD-1) and its partner on other cells (PD-L1), allowing the immune system to better recognize and attack tumors. They matter to investors because clinical trial results, approvals, safety issues, or wider adoption can rapidly change a drug maker’s revenue prospects and stock value, much like a breakthrough product reshaping an industry.

microsatellite-stable colorectal cancer medical

A form of colorectal cancer whose tumor cells show stable short DNA repeat regions, meaning the cell’s DNA copying system generally produces few errors; an everyday analogy is a photocopier that makes consistent copies rather than random smudges. It matters to investors because this biological pattern affects how well certain therapies, especially immune-based drugs, tend to work and therefore shapes clinical trial strategies, regulatory chances, market size and potential revenue for new treatments.

circulating tumor dna medical

Fragments of DNA shed by cancer cells into the bloodstream that act like tiny fingerprints of a tumor; they can be detected with a blood test rather than a biopsy. Investors care because circulating tumor DNA (ctDNA) enables faster, lower-cost ways to detect disease, track treatment response, identify emerging resistance and enroll patients in trials—factors that can materially affect the commercial prospects of diagnostics and therapeutics.

checkpoint inhibition medical

Checkpoint inhibition is a type of cancer treatment that blocks certain proteins on immune cells or tumors that act like brakes, allowing the body’s T cells to attack cancer more strongly. For investors, it matters because these therapies can transform clinical trial outcomes, drive regulatory approvals or safety concerns, and create large market opportunities or partnership and pricing questions—similar to taking the foot off a brake to speed up a car but increasing the risk of losing control.

h&e images medical

H&E images are microscope pictures of tissue that have been colored with two common dyes—hematoxylin and eosin—to show cell structure and patterns, much like coloring a map to highlight roads and landmarks. Pathologists use these images to diagnose disease, confirm tumor type and stage, and check how tissue responds to treatment; for investors they matter because they provide visual evidence used in clinical decisions, regulatory filings, and trial readouts that can affect a drug or diagnostic’s value.

• Four abstracts accepted across melanoma, colorectal cancer, and translational research

LEXINGTON, Mass.--(BUSINESS WIRE)-- Agenus Inc. (Nasdaq: AGEN), a leader in immuno-oncology innovation, today announced that four abstracts highlighting botensilimab (BOT), alone or in combination with balstilimab (BAL), have been accepted for presentation at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, taking place May 29–June 2, 2026, in Chicago, Illinois.

The accepted abstracts reflect continued progress of Agenus’ botensilimab and balstilimab immunotherapy program across colorectal cancer, melanoma, and translational research. They include the first presentation of Phase 2 clinical data for BOT with or without BAL in advanced cutaneous melanoma refractory or resistant to anti–PD-(L)1 therapy, with or without prior CTLA-4 inhibition, as well as a translational biomarker abstract evaluating an artificial intelligence foundation model in solid tumors and two trials-in-progress posters in colorectal cancer.

“Our presence at ASCO reflects strong momentum across the botensilimab and balstilimab program. From the first Phase 2 melanoma presentation to important colorectal cancer trial updates and innovative translational biomarker research, these presentations underscore our focus on delivering new immunotherapy options to patients who need them most,” said Garo H. Armen, PhD, Chairman and CEO of Agenus.

Presentation Details:

1. Abstract Title: Botensilimab (BOT) ± balstilimab (BAL) in patients (pts) with advanced cutaneous melanoma (cMEL) refractory/resistant (R/R) to anti–PD-(L)1 ± CTLA-4: A phase 2 trial
   Abstract No.: 9543
   Presenter: Michael Atkins MD; Georgetown Lombardi Comprehensive Cancer Center, Georgetown University Medical Center
   Session Title: Poster Session – Melanoma/Skin Cancers
   Location: Hall A – Posters and Exhibits
   Poster Board: 259
   Date/Time: May 31, 2026, 9:00 AM–12:00 PM CDT
   
   
2. Abstract Title: Artificial intelligence (AI) foundation model as a predictor of efficacy of next-generation checkpoint inhibition with botensilimab (BOT) + balstilimab (BAL) in solid tumors using pretreatment H&E images
   Abstract No.: 2535
   Presenter: Ryan Dalton, Noetik
   Session Title: Poster Session – Developmental Therapeutics—Immunotherapy
   Location: Hall A – Posters and Exhibits
   Poster Board: 325
   Date/Time: May 30, 2026, 1:30 PM–4:30 PM CDT
   
   
3. Abstract Title: The CO.33/BATTMAN trial: A phase 3 randomized study of botensilimab + balstilimab versus best supportive care in chemo refractory unresectable colorectal adenocarcinoma that is not dMMR/MSI-H
   Abstract No.: TPS3676
   Presenter: Jonathan Loree MD; BC Cancer; Canadian Cancer Trials Group, Queen’s University
   Session Title: Poster Session – Gastrointestinal Cancer—Colorectal and Anal
   Location: Hall A – Posters and Exhibits
   Poster Board: 441a
   Date/Time: May 30, 2026, 9:00 AM–12:00 PM CDT
   
   
4. Abstract Title: Phase 2 study of adjuvant botensilimab in combination with balstilimab in patients with microsatellite-stable colorectal cancer and persistent circulating tumor DNA following surgery and chemotherapy
   Abstract No.: TPS3689
   Presenter: Neil Segal, MD; Memorial Sloan Kettering Cancer Center
   Session Title: Poster Session – Gastrointestinal Cancer—Colorectal and Anal
   Location: Hall A – Posters and Exhibits
   Poster Board: 447b
   Date/Time: May 30, 2026, 9:00 AM–12:00 PM CDT

About Agenus

Agenus is a leading immuno-oncology company targeting cancer with a comprehensive pipeline of immunological agents. The company was founded in 1994 with a mission to expand patient populations benefiting from cancer immunotherapy through combination approaches, using a broad repertoire of antibody therapeutics, adoptive cell therapies (through MiNK Therapeutics) and adjuvants. Agenus has robust end-to-end development capabilities, across commercial and clinical cGMP manufacturing facilities, research and discovery, and a global clinical operations footprint. Agenus is headquartered in Lexington, MA. For more information, visit www.agenusbio.com or @agenus_bio. Information that may be important to investors will be routinely posted on our website and social media channels.

About Botensilimab (BOT)

Botensilimab (BOT) is a human Fc enhanced multifunctional anti-CTLA-4 antibody designed to boost both innate and adaptive anti-tumor immune responses. Its novel design leverages mechanisms of action to extend immunotherapy benefits to “cold” tumors which generally respond poorly to standard of care or are refractory to conventional PD-1/CTLA-4 therapies and investigational therapies. Botensilimab augments immune responses across a wide range of tumor types by priming and activating T cells, downregulating intratumoral regulatory T cells, activating myeloid cells and inducing long-term memory responses.

Approximately 1,200 patients have been treated with botensilimab and/or balstilimab in phase 1 and phase 2 clinical trials. Botensilimab alone, or in combination with Agenus’ investigational PD-1 antibody, balstilimab, has shown clinical responses across nine metastatic, late-line cancers. For more information about botensilimab trials, visit www.clinicaltrials.gov.

About Balstilimab (BAL)

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. It has been evaluated in more than 900 patients to date and has demonstrated clinical activity and a favorable tolerability profile in several tumor types.

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 its botensilimab and balstilimab programs, expected regulatory timelines and filings, 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 Annual Report on Form 10-K for 2025, and subsequent Quarterly Reports on Form 10-Q 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.

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Source: Agenus Inc.