FDA Grants RPDD to 177Lu-omburtamab-DTPA For Medulloblastoma

The FDA has granted a rare pediatric disease designation to ¹⁷⁷Lu-omburtamab-DTPA (lutetium-17), a monoclonal B7-H3 antibody for the treatment of pediatric patients with refractory medulloblastoma, according to a press release by Y-mAbs Therapeutics, Inc.¹ 

The agent has been radiolabeled with lutetium-177. It is currently being evaluated in 2 clinical trials, one in pediatric patients with refractory medulloblastoma and the other in B7-H3-positive central nervous system/ leptomeningeal metastases tumors in adults.

“We are dedicated to bring ¹⁷⁷Lu-omburtamab-DTPA to patients who desperately need alternative methods of treatment. We are very pleased by this recognition by the FDA and look forward to expanding the ongoing phase 1 studies with 177Lu-omburtamab-DTPA into separate phase 2 arms,” said Claus J. Moller San Pedro, MD, PhD, CEO of Y-mAbs Therapeutics, Inc, in a press release.

The phase 1/2 pediatric trial (NCT04167618) has an estimated enrollment of 40 participants and an estimated completion date of December 2024. The primary end points of the study are the incidence of adverse events (AEs) and serious AEs at 1 and 2 years. Secondary end points include the analysis of lutetium-177 activity in the blood at 2 weeks, the absorbed radiation dose of leutitum-177 in blood and cerebrospinal fluid at 2 weeks, maximum plasma concentration, elimination half-life, response, duration of response, overall survival, and progression-free survival.²

The study is split into 2 parts. In part 1, patients received the agent up to 2 cycles. In part 2, the agent was administered up to 5 cycles. 

In order to participate in the study, patients must be between 3 and 19 years of age, have histologically confirmed medulloblastoma, be recurrent or refractory to frontline therapy, be in cytological or radiographic remission, have a life expectancy of at least 3 months, and acceptable hematological status and liver function. Patients with residual disease measuring >5 mm in the smallest diameter, ventriculoperitoneal shunts without programmable valves, grade 4 neurotoxicity, uncontrolled life-threating infection, or received any prior anti-B7-H3 therapy, are not eligible to participate.

“The RPDD makes us eligible for a Priority Review Voucher [PRV] upon potential approval of the biologics license application for this rare pediatric cancer. Among our leading compounds under development, four now have RPDDs, and this designation for 177Lu-omburtamab-DTPA further increase our chances of ultimately receiving multiple PRVs,” said Thomas Gad, founder, chairman and president of Y-mAbs, in the press release.

The study is currently recruiting in Minnesota, New York, Oregon, and Texas.

_REFERENCES:

_{1.Y-mAbs’ 177Lu-omburtamab-DTPA for the treatment of patients with medulloblastoma granted rare pediatric disease designation by FDA. News release. Y-mAbs Therapeutics, Inc. October 7, 2021. Accessed October 11, 2021. https://bit.ly/2YCzmFo}

_{2.177Lu-DTPA-Omburtamab radioimmunotherapy for recurrent or refractory medulloblastoma. ClinicalTrials.gov. Accessed October 11, 2021. https://bit.ly/3oR21Sn.}