Palleon Pharmaceuticals has announced positive outcomes from its Phase I/II GLIMMER-01 study evaluating E-602 in combination with Regeneron's cemiplimab (Libtayo) for patients with solid tumors resistant to anti-PD-(L)1 therapies. The study assessed the safety, tolerability, pharmacokinetics, and anti-tumor activity of the combination in 21 participants with melanoma, esophagogastric junction cancer, and non-small cell lung cancer (NSCLC).
E-602: A Novel Sialidase Enzyme Therapeutic
E-602, a first-in-class human sialidase enzyme therapeutic, is based on Palleon's Enzyme Antibody Glyco-Ligand Editing (EAGLE) oncology platform. The GLIMMER-01 trial is a single-arm, open-label study designed to evaluate E-602's potential to modulate the immune system by targeting glyco-immunology.
Tolerability and Clinical Outcomes
The combination therapy was generally well-tolerated, with no dose-limiting toxicities observed. Notably, patients with tumor hypersialylation, a condition where tumor cells exhibit elevated levels of sialoglycans, experienced more favorable clinical outcomes compared to those without hypersialylation. One participant with anti-PD-1 resistant melanoma achieved a confirmed partial response, and six other participants experienced disease stabilization.
Conversely, all participants lacking hypersialylation experienced disease progression, highlighting the potential of hypersialylation as a predictive biomarker for E-602 response.
Mechanism of Action and Immune Modulation
Paired tumor biopsies from subjects with hypersialylation indicated that E-602 induced tumor desialylation and immune modulation within the tumor microenvironment. This suggests that E-602 may enhance the efficacy of immune checkpoint inhibitors by altering the glycosylation profile of tumor cells and promoting immune cell infiltration.
Expert Commentary
"E602 is the first candidate in a brand new class of therapeutics designed to modulate the immune system by targeting glyco-immunology," said Jim Broderick, CEO and founder of Palleon Pharmaceuticals. "Palleon is building a rich pipeline of first-in-class drug candidates with the potential to improve and extend the lives of patients with diseases characterised by immune dysfunction, including cancer and autoimmunity."
Li Peng, chief scientific officer at Palleon Pharmaceuticals, added, "The proof of mechanism and antitumor responses observed with E-602 as a combination therapy for patients with solid tumours further validate the therapeutic potential of targeting glyco-immunology to regulate the immune response in treating cancer and autoimmune diseases."
