What happened

Shares of Agenus (NASDAQ:AGEN) jumped over 23% today after the company announced a presentation at the American Society of Clinical Oncology (ASCO) meeting discussing the progress of AGEN1181 in solid-tumor cancers. 

The drug candidate delivered clinical benefit in 70% of patients with advanced tumors in the small-scale study, both as a monotherapy and in combination with another drug candidate from the company. If the results can hold up in larger clinical trials, AGEN1181 might have broad potential to improve outcomes for patients with a wide array of solid tumor cancers. 

Investors have decided to price in some of that potential today. As of 12:39 p.m. EDT, the small-cap stock had settled to a 17.4% gain.

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So what

AGEN1181 is a next-generation antibody that inhibits CTLA-4, which is a protein that suppresses immune responses and is overexpressed in many solid tumors. The Nobel Prize in Medicine in 2018 was awarded for establishing CTLA-4 as a target for immunotherapy. 

What makes the drug candidate different? Scientists at Agenus have engineered the crystallizable fragment (Fc) of AGEN1181 to have unique binding properties thought to increase the activity of immune cells. The edits could also improve safety and boost efficacy compared to prior-generation anti-CTLA-4 antibodies. 

Early results are encouraging. According to the ASCO presentation, AGEN1181 triggered clinical benefit -- defined as achieving stable disease, a partial response, or a complete response -- in 70% of individuals with advanced tumors. All patients had previously received other checkpoint inhibitor drugs and experienced progression of their cancer. The results are from individuals who received AGEN1181 alone or in combination with the company's anti-PD-1 drug, balstilimab. 

The results suggest AGEN1181 could have broad potential in treating solid tumor cancers such as melanoma and non-small cell lung cancer (NSCLC), especially in patients who fail to respond or don't maintain responses to existing checkpoint inhibitors. The results also support the rationale for engineering Fc regions of tumor-fighting antibodies, which could be useful across the company's pipeline.

Now what

Agenus has struggled to convince Wall Street that its pipeline is relevant in the ultra-competitive biopharma industry. The stock price has remained volatile, and the business has remained pinned below a market valuation of $600 million for the last year. The ASCO presentation for AGEN1181 is a good start in turning heads and earning attention, but investors need to be cautious until more detailed, later-stage results are published.