Agenus

Agenus (formerly Antigenics Inc.) was founded in 1994 by Garo H. Armen and Pramod K. Srivastava. The company has pioneered immunotherapies, including heat shock protein-based cancer vaccines, a program that has developed into its Prophage Series of personalized anti-cancer vaccines. Antigenics became a public company in February 2000 on the NASDAQ exchange with the ticker symbol AGEN. In 2000 Agenus acquired Aquila Biopharmaceuticals and a year later it acquired Aronex Pharmaceuticals. In February 2014 the company acquired a European firm, 4-Antibody, along with their portfolio of checkpoint modulators (CPMs) and a platform (Retrocyte Display® technology) to rapidly and efficiently discover new antibodies.

In October 2013, Agenus CEO Garo Armen issued a press release revealing that after an 18-month follow up on the RTS,S Malaria vaccine using QS21-Stimulon®, it was working well enough to support a regulatory filing in 2014. This was the first proof of the efficacy of Agenus's patented "QS-21 Stimulon" adjuvant

In April 2014, Agenus signed a deal with Merck potentially worth $100 million. Under the terms of that deal, Agenus is using its proprietary Retrocyte Display technology to discover antibodies against a pair of undisclosed checkpoint targets for the treatment of cancer. Agenus has advanced two of its own CPM candidates into early drug development and the company is planning to advance several more antibodies in clinical trials.

Today, Agenus is focused on developing a range of immuno-oncology products, including the Prophage vaccines, multiple checkpoint modulators (also known as checkpoint inhibitors or checkpoint antibodies) and its QS21-Stimulon adjuvant. The company's personalized, heat shock protein-based vaccines are in Phase 2 studies. The QS-21 Stimulon adjuvant platform is partnered with GlaxoSmithKline and Janssen. Several of those collaborations involve Phase 3 trials. Altogether, the company and its partners are sponsoring approximately 20 clinical trials of Agenus products.

In August 2023, Agenus announced a strategic restructuring to prioritize its botensilimab and balstilimab (BOT/BAL) clinical programs. The plan included a 25% reduction in its workforce (approximately 85 positions) and the temporary suspension of most preclinical and clinical programs not related to the BOT/BAL combination. The company stated the reorganization was intended to reduce annual operating expenses by approximately $40 million.

In 2025, Agenus sold their CDMO business to Zydus Lifesciences including their two biologics manufacturing sites in Emeryville and Berkeley. In addition, they would partner with Zydus to commercialize their molecules in India.

Checkpoint modulators (CPMs) interfere with cancers’ ability to “hijack” natural immune defense systems. To protect the body against disease, but without attacking healthy cells, the immune system uses multiple “checkpoint” systems. Some checkpoints stimulate immune responses while others inhibit them. Cancer cells can evolve means to evade checkpoints, and CPMs can reverse that effect, helping the immune system better fight the cancer.

Agenus has programs targeting the checkpoint modulators GITR, OX40, CTLA-4, LAG-3, TIM-3 and PD-1. The company is expanding that portfolio by using a proprietary process to generate fully human therapeutic antibody drug candidates. The platform is a high-throughput approach incorporating IgG format human antibody libraries expressed in mammalian B-lineage cells.

The Prophage series of patient-specific cancer vaccine candidates can also enhance the immune system's response to tumors. Because each cancer is unique, the vaccine is derived from the patient's own tumor sample. To process these samples, Agenus has established a multi-product "good manufacturing practices" facility, which has already helped process over 1,000 tumor samples from across the globe.

The company's QS-21 Stimulon® adjuvant platform strengthens and broadens immune responses to antigens on cancers or foreign invaders’ surfaces. Agenus has multiple partnerships around this product to study its effects with vaccines for diseases including Alzheimer's, melanoma, and malaria. In October 2013, GlaxoSmithKline and Agenus announced positive data from an 18-month follow-up of GSK's RTS,S malaria vaccine with QS21-Stimulon. GSK stated that the treatment was working well enough to support a regulatory filing. RTS,S is the most advanced vaccine for malaria in development.