FDA Grants Orphan Drug Designation to CLR 131 for Pediatric Osteosarcoma

The US Food and Drug Administration (FDA) has granted an orphan drug designation to Cellectar Biosciences, Inc.’s CLR 131 for treatment of pediatric osteosarcoma.

“Osteosarcoma is the most common type of primary bone cancer occurring most frequently in children. Currently, there are no commercially available drugs for pediatric sarcoma, including osteosarcoma,” said John Friend, MD, chief medical officer of Cellectar, in a recent statement. “This orphan designation for osteosarcoma is the fourth such designation granted by the FDA to CLR 131 for the treatment of rare pediatric cancers in the last 6 months, and we look forward to evaluating CLR 131 in these deadly and underserved diseases.”

Currently, CLR 131 is being studied in a phase 2 clinical trial in relapsed/refractory multiple myeloma (R/R MM) and a range of B-cell malignancies and in a phase 1b clinical trial in patients with R/R MM which is exploring fractionated dosing.

A phase 1 study with CLR 131 in pediatric solid tumors and lymphoma is also currently being initiated, and a second phase 1 study exploring the use of CLR 131 in combination with external beam radiation for head and neck cancer is being planned as well.

A small-molecule, targeted Phospholipid Drug Conjugate, CLR 131 has been designed to directly deliver cytotoxic radiation to cancer cells, according to Cellectar Biosciences.

Previously, CLR 131 was granted a rare pediatric disease designation and orphan drug designation for Ewing’s sarcoma. CLR 131 has also been granted an orphan drug designation for rhabdomyosarcoma and a rare pediatric disease designation and orphan drug designation for neuroblastoma.