Rocket Pharmaceuticals Withdraws Gene Therapy Application for Rare Blood Disorder

Rocket Pharmaceuticals, a New Jersey-based biotech company, has voluntarily withdrawn its biologics license application (BLA) for mozafancogene autotemcel, a gene therapy intended to treat Fanconi anemia, a rare blood disorder. This decision, announced in an SEC filing on October 6, 2025, marks a significant shift in the company's strategic focus and pipeline priorities.

Strategic Realignment and Program Reprioritization

The withdrawal of the BLA follows Rocket's previously announced corporate reprioritization initiative in July 2025. This initiative, which resulted in an approximately 30% reduction in workforce, aimed to focus the company's resources on programs with the clearest regulatory and commercial pathways. The decision to withdraw the application was attributed to "business and strategic considerations" rather than concerns about the safety or efficacy of mozafancogene autotemcel, also known as fanca-cel.

Rocket emphasized that data to date continue to support a favorable risk-benefit profile for the program, with no significant safety concerns documented. The company has also withdrawn its marketing authorization application with the European Medicines Agency.

Fanca-cel and Fanconi Anemia

Fanca-cel is an investigational gene therapy that uses hematopoietic stem cells derived from patients themselves, modified to contain a functional copy of the FANCA gene. The therapy was being developed to treat Fanconi anemia, a rare genetic disorder characterized by bone marrow failure, congenital defects, and an increased risk of cancer.

Regulatory Challenges and Pipeline Adjustments

The past year has been turbulent for Rocket Pharmaceuticals, with several regulatory setbacks affecting its gene therapy pipeline:

1. In May 2025, the FDA placed a clinical hold on Rocket's pivotal Phase II Danon disease program following a patient death. This hold was lifted in August, allowing the company to restart mid-stage development of RP-A501, its gene therapy for Danon disease.

2. In 2024, the FDA rejected Rocket's gene therapy Kresladi for severe leukocyte adhesion deficiency-I, citing the need for additional clarity on manufacturing processes.

Despite these challenges, Rocket continues to work with the FDA on resubmitting its application for Kresladi, with expectations to refile before the end of 2025.

Future Prospects for Fanca-cel

While Rocket has withdrawn its current application for fanca-cel, the company has not completely abandoned the program. According to the SEC filing, Rocket will consider external partnership opportunities that could potentially enable the advancement of RP-L102 in the future. The withdrawal preserves Rocket's ability to re-engage with regulators at a later date, should a suitable strategic or partnership pathway emerge to sustainably progress the program.

As the pharmaceutical industry continues to navigate the complex landscape of gene therapy development and regulatory approval, Rocket Pharmaceuticals' strategic decisions reflect the challenges and opportunities facing companies in this innovative field.