Satellite Bio Secures FDA Rare Pediatric Disease Designation for UCD Therapy SB-101

Rare Daily Staff

The U.S. Food and Drug Administration granted Satellite Biosciences Rare Pediatric Disease designation for its lead therapy candidate, SB-101, aimed at treating urea cycle disorders, a group of rare, life-threatening metabolic conditions that primarily affect infants and children.

The FDA’s Rare Pediatric Disease designation is granted to therapies targeting serious or life-threatening conditions affecting individuals under 18. If SB-101 ultimately receives marketing approval, Satellite Bio may qualify for a Priority Review Voucher, an incentive that can accelerate review timelines for another drug or be sold to other companies.

The designation marks a regulatory milestone for the company as it advances a first-in-class, off-the-shelf liver cell therapy designed to restore metabolic liver function. SB-101 is intended for infants with severe early-onset urea cycle disorders (UCDs), a population with limited treatment options and high risk of mortality and long-term neurological damage.

UCDs impair the body’s ability to remove ammonia from the bloodstream, leading to toxic accumulation that can result in encephalopathy, seizures, coma, and death. Despite current management strategies, mortality rates exceed 25 percent, and approximately half of patients experience lasting cognitive impairment. No curative treatments are available during the critical first weeks of life.

Satellite Bio’s platform focuses on delivering healthy hepatocytes to patients using pre-manufactured, cryopreserved cell therapies that can be administered on demand. Unlike traditional cell therapies that are often patient-specific, SB-101 is designed as an off-the-shelf product, which could improve accessibility, scalability, and cost efficiency.

The liver plays a central role in more than 500 biological processes, including detoxification and protein synthesis. In UCDs and other severe liver diseases, dysfunction of hepatocytes—the liver’s primary functional cells—drives disease progression. Satellite Bio aims to address this root cause by enabling transplanted cells to engraft and restore metabolic activity.

In addition to SB-101, the company is developing a broader pipeline targeting pediatric and adult liver diseases.

“This designation underscores both the urgent need in UCDs and the potential of our approach to restore essential liver function,” said Tom Lowery, president and CEO of Satellite Bio, in a statement. The company plans to initiate a phase 1/2 clinical trial of SB-101 in 2026.