Cellectar Biosciences (Nasdaq:CLRB), announced on 5/10/18 that the U.S. Food and Drug Administration (FDA) Office of Orphan Products Development has granted Orphan Drug Designation to CLR 131, the company’s lead Phospholipid Drug Conjugate™ (PDC) product candidate, for the treatment of rhabdomyosarcoma, a rare pediatric cancer.
“Rhabdomyosarcoma is the most common type of tissue sarcoma in children. While initial response to treatment is generally favorable, there is an important need for new treatments, especially in children who experience relapse.” said John Friend, M.D., chief medical officer of Cellectar. “Cellectar is committed to working closely with the FDA to fully evaluate the potential for targeted delivery of CLR 131 to address this currently unmet medical need.”
Rhabdomyosarcoma (RMS), a malignant tumor of mesenchymal origin, is the most common soft tissue sarcoma in children, accounting for approximately 40% of childhood soft tissue sarcomas in the United States. The incidence is about 4.5 cases per 1 million per year in children younger than 15 years and more than 50% are younger than 10 years at diagnosis. Approximately 340 new cases are diagnosed each year in North America and the prognosis is favorable with a 64% 5-year survival in children aged birth to 19 years.
CLR 131 is Cellectar’s investigational radioiodinated PDC therapy that exploits the tumor-targeting properties of the company's proprietary phospholipid ether (PLE) and PLE analogs to selectively deliver radiation to malignant tumor cells, thus minimizing radiation exposure to normal tissues. CLR 131, is in a Phase 2 clinical study in relapsed or refractory (R/R) MM and a range of B-cell malignancies and a Phase 1 clinical study in patients with (R/R) MM exploring fractionated dosing. In 2018 the company plans to initiate a Phase 1 study with CLR 131 in pediatric solid tumors and lymphoma, and a second Phase 1 study in combination with external beam radiation for head and neck cancer.