Di-HSG DOTA peptide (IMP-288) (IMP-288)

IMP-288 is a synthetic di-HSG peptide, engineered to serve as a radiolabeled hapten for pretargeted radioimmunotherapy and imaging in oncology. It contains moieties (histamine-succinyl-glycine, HSG) that bind with high affinity to specific bispecific antibodies pretargeted to tumor antigens such as carcinoembryonic antigen (CEA) or trophoblast cell surface antigen 2 (Trop-2). The DOTA chelator allows labeling with a variety of radioisotopes (e.g., 177Lu, 111In, 68Ga), enabling applications in PET/SPECT imaging and targeted radiation therapy. IMP-288 itself is not a receptor, enzyme, or transporter, and has no endogenous biological activity. It enables highly specific targeting of radiotherapy to tumors, with rapid renal clearance of unbound peptide reducing off-target systemic toxicity. Clinical investigations have explored its safety and efficacy in several solid tumor indications, predominantly colorectal cancer, pancreatic cancer, and prostate cancer.

Other names

Di-HSG DOTA peptideIMP288DOTA-di-HSG peptide[111In]IMP-288[177Lu]IMP-288[68Ga]IMP-288Hapten-peptide IMP288

Pretargeted delivery: After administration of a bispecific antibody specific for both a tumor antigen (e.g., CEA or Trop-2) and the HSG hapten, IMP-288 is injected and selectively binds to the tumor-localized antibody, delivering a radioactive payload for imaging (PET/SPECT) or therapy (PRIT). Rapid clearance/reduced toxicity: Unbound IMP-288 is rapidly eliminated through the kidneys due to its small size, reducing systemic radioactivity exposure.