BOSTON—PureTech Health plc has shared new data on galectin-9 as a novel target for cancer immunotherapy, providing evidence that therapies targeting galectin-9 may enable the immune system to attack an array of solid tumors. The data were shared in a scientific poster presented at the June session of the American Association for Cancer Research 2020 Virtual Annual Meeting.
“These new data clearly establish the importance of galectin-9 as a therapeutic target, given that its high expression across tumor types correlates with poor patient outcomes,” said Joseph Bolen, Ph.D., chief scientific officer at PureTech. “Our analysis of more than 1,000 samples from human breast cancer tumors found that high levels of galectin-9 are associated with shorter time to disease relapse as well as with a tumor microenvironment that lacks cytotoxic CD8+ T cells that would otherwise be able to attack the tumor.”
“Our first-in-class monoclonal antibody, LYT-200, is designed to target and inhibit galectin-9 and thereby reverse this suppression of the immune system to boost its ability to destroy tumors. We’re proud to be presenting this research at AACR and look forward to advancing LYT-200 into the clinic later this year, as well as to progressing our work on galectin-9 as a biomarker,” Bolen continued.
LYT-200 is expected to enter a first-in-human, Phase 1a/1b study in 2020 in hard-to-treat cancers — including pancreatic, cholangiocarcinoma and certain types of colorectal and liver cancers — which remain insufficiently responsive or resistant to currently approved checkpoint inhibitors. PureTech has previously presented data demonstrating LYT-200’s efficacy in reducing tumor growth and reactivating human effector T cells in preclinical, patient-derived tumor culture models.
In breast cancer, galectin-9 expression was associated with tumors showing pathological features like high tumor grade and estrogen receptor negativity, as well as features characteristic of an immunosuppressed tumor microenvironment — including the absence of CD8+ T cells. These data suggest that galectin-9 could be significant as a therapeutic target for a range of cancers.