131I-CLR 131 (131I-CLR-1404, 131I-NM404) is a small molecule, an alkyl phosphocholine (APC), from the family of phospholipid ether (PLE) analogs radiolabeled for cancer therapy. The molecule targets the phosphatidylinositol 3-kinase (PI3K)/Akt survival pathway, which is overexpressed in many types of cancer.
Preclinical data have clearly shown selective uptake and retention by both primary tumors and metastases in over 60 models including colon, glioma, triple negative breast and pancreatic tumor xenograft models. Preclinical therapeutic tests with 131I-CLR 131 have revealed time-dependent tumor shrinkage and disappearance.
A Phase Ia dosimetry trial was completed in 2010 and demonstrated initial safety, tumor imaging and pharmacokinetic consistency. Subsequent cohorts of patients were treated with doses of up to 37.5 mCi/m². One new trial was initiated in multiple myeloma patients in 2015. The priority indication target in presently running clinical trials is multiple myeloma.