Cellectar Biosciences, Inc. announced the first patient has been enrolled in its Phase 1b clinical trial evaluating iopofosine I 131, a novel phospholipid radiotherapeutic conjugate, in pediatric patients with relapsed or refractory malignant high-grade gliomas (pHGG). The open-label study (NCT05610891) will assess two dosing regimens to identify the optimal iopofosine I 131 Phase 2 recommended dose and schedule in pHGG patients and evaluate safety and tolerability. The study is supported by a $2 million Fast Track SBIR grant from the National Institute of Health?s National Cancer Institute (NCI), which was awarded based in part on the promising Phase 1a trial data.

Pediatric high-grade gliomas are aggressive malignant tumors that form in the brain or spinal cord of children, adolescents, and young adults. Comprising a small but devastating portion of childhood cancers with an approximate incidence rate of 1,300 patients in the US (1.1-1.178 per 100,000 children), these tumors originate in the glial cells of the brain and spinal cord and are known for their rapid growth and resistance to conventional treatments. They are also responsible for over 40% of childhood brain tumor death and are the more common cause of tumor related death for children.

The current standard of care for pediatric high-grade gliomas typically involves a combination of extensive brain surgery, radiation therapy, and chemotherapy at the time of initial diagnosis. However, the outcomes remain unsatisfactory for newly diagnosed patients and are dismal for relapsed or progressive disease. The five-year overall survival rate for high-grade gliomas in children is less than 20% and limited improvements were seen over the years.

The disease's aggressive clinical nature and inherent genomic resistance often leads to significant challenges in achieving long-term remission and therapies with new mechanisms of action are urgently needed.