Galectin-1 (Gal-1) protein has been found as a new PET imaging biomarker for immune checkpoint blockade (ICB) therapy. This allows doctors to predict how tumors will respond before starting treatment. The information from Gal-1 PET imaging can also help with patient stratification and improve immunotherapy, leading to targeted interventions and better patient outcomes.Information obtained from Gal-1 PET imaging could potentially be utilized to help categorize patients and enhance immunotherapy, leading to targeted treatments and improved patient results. This study was featured in the May edition of The Journal of Nuclear Medicine.
Immunotherapies, such as ICB, have shown promise in treating melanoma, non-small cell lung cancer, and other tumor types. However, only a subset of patients see positive results, with response rates ranging from five to 60 percent.
“Identifying suitable candidates for immunotherapy and determining their response remains a difficult task,” noted Zhaofei Liu, PhD, Boya Distinguished Professor at Peking University in Beijing, China. “Current clinical guidelines for assessing solid tumor responses to immunotherapy rely on CT and MRI scans, but these methods cause significant delays in evaluating treatment effectiveness. Molecular imaging techniques, particularly PET scans, have become reliable tools for predicting the effectiveness of immunotherapy by providing real-time, quantitative, and noninvasive assessment of biomarkers in the body.”
The research utilized a mouse model to discover new patterns for selecting eligible patients for immunotherapy and assessing their responses.Imaging biomarkers are used to determine tumor responses to ICB therapy. One study used proteomic analysis to investigate the relationship between Gal-1 expression and tumor response to ICB therapy. The researchers found that tumors with low levels of Gal-1 expression showed a positive response to ICB therapy.
In the next phase of the study, Gal-1 was labeled with 124I to create a radiotracer called 124I-α-Gal-1. Small animal PET imaging and biodistribution studies were then conducted to evaluate the specificity of the radiotracer. The PET imaging with 124I-αGal-1 was able to show the immunosuppressive status of the tumor microenvironment. This allowed for the prediction of ICB resistance before treatment.The article discusses a new strategy for predicting the effectiveness of immunotherapy for tumors. Researchers have developed a method using a Gal-1 inhibitor to improve the chances of success for tumors that were not initially expected to respond well to immunotherapy. According to Liu, this approach has the potential to personalize treatment for individual patients in the future. The research was published online in March 2024.
