The CLR 131 is an investigational radioiodinated PDC therapy, which exploits the tumor-targeting properties of the firm’s phospholipid ether (PLE) and PLE analogs to selectively deliver radiation to malignant tumor cells, enabling to minimize radiation exposure to normal tissues.
Osteosarcoma is said to derive from bone forming mesenchymal or connective tissue and cells. It is the commonly diagnosed primary bone malignancy among children and adolescents.
At present, CLR 131 is in phase 2 clinical study in R/R MM and various B-cell malignancies, as well as in phase 1b clinical study in patients with R/R MM exploring fractionated dosing.
According to the company, the objective of the multicenter, open-label and Phase 1b dose-escalation study is the characterization of safety and tolerability of CLR 131 in patients with R/R MM.
Patients in cohorts 1-4 secured received single doses of CLR 131 ranging from 12.5 mCi/m2 to 31.25 mCi/m2.
Cellectar is also starting a phase 1 study with CLR 131 in pediatric solid tumors and lymphoma, and planning second phase 1 study in combination with external beam radiation for head and neck cancer.
From May this year, the company secured RPDD for CLR 131 in four pediatric cancers, including neuroblastoma, rhabdomyosarcoma, Ewing’s Sarcoma and osteosarcoma.
If any of these indications achieve approval, the RPDD will allow the company to secure priority review voucher, which can be used to receive priority review for a future NDA or BLA submission.
The vouchers can also be shifted or sold to another entity. Five priority review vouchers have been sold between $110m and $150m each, over the last 16 months.
Cellectar Biosciences chief medical officer Dr John Friend said: “CLR 131 has demonstrated promise as an anticancer agent in preclinical and clinical settings, and we are working now to establish its impact on various rare and deadly pediatric cancers.
“Cellectar is pleased to have the opportunity to work closely with the FDA on our planned Phase 1 trial for these indications and we remain committed to advancing the pediatric programs as rapidly as possible.”