Neuroblastoma Therapy Gets Rare Pediatric Disease Designation

A Rare Pediatric Disease designation was granted by the U.S. Food and Drug Administration (FDA) this morning to Cellectar Biosciences for CLR 131, intended for the treatment of neuroblastoma.

CLR 131 is Cellectar’s lead phospholipid drug conjugate (PDC). It was granted Orphan Drug designation for the same indication in March.

The drug is the first potential therapy that would utilize a PDC tumor-targeting delivery platform to deliver a cytotoxic radioisotope (iodine-131) directly to the tumor cells. The new designation is based upon preclinical and interim Phase 1 study data, in which treatment with CLR 131 exhibited a novel approach to treating solid and hematological tumors. The drug is being developed so that it can potentially provide patients with therapeutic benefits, including: overall survival (OS), an improvement in progression-free survival (PFS), surrogate efficacy marker response rate, and overall quality of life (QOL).

In children under 5 years, neuroblastomas can develop anywhere that a group of nerve cells, or neuroblasts, already exists. The condition grows from immature neuroblasts found in an array of areas throughout the body, and typically continues to develop in and around the adrenal glands, which rest above the kidneys. According to a study published in the Journal of Nuclear Medicine, CLR 131 had already been tested in models of adult cancers and discovered to target cancer cells with very high specificity.

“Neuroblastoma is a devastating cancer most often found in infants and young children. The grant of RPDD for CLR 131 in conjunction with the orphan drug designation we received in March highlight the critical need for new treatments in the fight against this disease,” said John Friend, M.D., chief medical officer of Cellectar in a press release. “We look forward to working with the FDA to bring this potential therapy to pediatric patients and expect to begin a clinical study in neuroblastoma during the second half of 2018.”

With the University of Wisconsin Carbone Cancer Center, Cellectar is expected to initiate its first Phase 1 clinical trial of CLR 131 at the end of the second quarter of this year. The study will enroll patients with relapsed/refractory (R/R) pediatric cancers, with 2 cohorts: one with non-brain-related cancers like neuroblastoma, and a second of patients with malignant brain tumors. All enrolled patients will receive a single 30-minute infusion of CLR 131 and will be followed for up to 85 days with safety and efficacy assessments throughout.

“Finding the right collaborators and academic sites who are engaged in clinical research, but also able to administer CLR 131 as a radiotherapeutic can be a bit of a challenge,” said Dr Friend in an exclusive interview with Rare Disease Report. “Fortunately, in neuroblastoma, one of the second-line therapies that is used off-label is MIBG 131, which is essentially a delivery of a very, very high dose iodine 131 to pediatric patients. A lot of these major academic centers, like the University of Wisconsin, have these MIBG-capabilities.”

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 the second half of 2018 the company plans to initiate a Phase 1 study with CLR 131 in pediatric solid tumors and lymphoma, as well as a Phase 1 study in combination with external beam radiation for head and neck cancer.

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