Agenus Inc. (NASDAQ:AGEN) has expanded its Phase 2 study into colon cancer based on new objective clinical response in a patient with colorectal cancer in addition to the 27% tumor reduction and biomarker reduction reported in MSS colon cancer patients.
AGEN1181 shows 27% tumor reduction in colorectal cancer
Following the recent response in colon cancer, AGEN1181 +/- anti-PD1 (balstilimab) demonstrated four clinical responses and significant tumor reduction of over 27% in a fifth patient. Also, 19 patients out of 41 treated patients attained disease stabilization in what the company planned as a dose-escalation trial.
The company recently presented the first-ever intratumoral Treg depletion reports with CTLA-4 antibody in clinical studies. AGEN1181 alone or in combination with balstilimab produced a complete response in PD-L1 as monotherapy in MSS endometrial cancer patients and as a combination with balstilimab. There were partial responses in a patient with colorectal cancer and another with refractory ovarian cancer following treatment with AGEN1181 combined with balstilimab. There was a 27% major tumor reduction in MSS colorectal cancer with biomarker reduction from 298 to two when AGEN1181 was used in combination with balstilimab.
Most importantly, clinical benefit and responses have been reported in Phase 1 AGEN1181 study in polymorphism patients in FcyRIIIA alleles for nonresponsive patients to CTLA-4 antibodies. The second phase, multicentre, open-label study, will focus on colorectal cancer and some solid tumors such as melanoma and lung cancer.
AGEN1181 showing potential in nonresponsive tumors
Dr. Joseph Grossman, Agenus Head of Exploratory Medicine and gastrointestinal cancers expert, said the early data is exciting, especially in aggressive tumors that are unresponsive to immune therapies. Grosman said that AGEN1181 could broaden the number of responses to CPIs and treat cancers often considered unresponsive to immune therapies. He added that he is delighted to see the potential benefit broaden for the anti-CTLA-4 design more, so it’s FC-enhancing and validation of the company’s incredible R&D potential. Grossman joined Agenus recently as the exploratory medicine head from Harvard Medical School, where he was a Medicine instructor.