Rocket Drug Submits FDA for Gene Treatment with Rare Blood Diseases
Rocket Pharmaceuticals’ gene therapy has ended its regulatory journey before accepting the FDA decision. The company has withdrawn its submission for candidates for treatment of Fanconi anemia, a rare hereditary blood disease.
The company said in a regulatory filing on Friday that it was voluntary withdrawal of a biologics license application (BLA) called Mozafancogen Autotemcel at an earlier development stage after the previously announced company repositioning. In July, Cranbury, New Jersey-based operations underwent a reorganization operation, ruling about 30% of its employees and shifting the company's focus to the cardiovascular program, which it says offers opportunities to create near- and long-term value. Through the reorganization, Rocket stopped any new internal spending on RP-L102 and withdrew regulatory submissions for European treatment.
In Faconi anemia, the bone marrow does not produce healthy blood cells and platelets, putting patients at greater risk for blood diseases and certain types of cancer. Treatment includes drugs that stimulate the production of red blood cells and white blood cells. Another option is bone marrow transplant.
RP-L102 is an in vivo gene therapy that modifies patients' own stem cells early in the disease by using lentiviral vectors. In a pivotal phase 2 study, the results showed that 8 of the 12 evaluable patients maintained sustained genetic correction. The treatment is well tolerated. In Friday's regulatory filing, Rocket said its decision to withdraw the BLA was a commercial and strategic move and did not reflect any concerns about the safety or efficacy of RP-L102.
In a note sent to investors, Leerink Partners analyst Mani Foroohar said Rocket’s move was not surprising, as the company previously signaled to RP-L102 and the wider lentiviral portfolio was deprived. Even so, Foroohar said optimism about Fanconi anemia gene therapy can be placed with partners during or after the FDA review, as this will make another company a commercially ready asset.
“Management confirmed that discussions on the partnership are underway, although BLA withdrawal signals have widely taken advantage of the benefits of lentiviral assets,” Foroohar said.
Looking ahead, most of Rocket's focus will be on RP-A501, a candidate for its gene therapy Danon disease, a rare hereditary disease that weakens the heart muscle and leads to heart failure. In May, Rocket reported a death in a clinical trial that is believed to be linked to drugs used as a pretreatment regimen for gene therapy in a phase 2 study. In August, the FDA canceled clinical retention for the program; Rocket said it will be performed at a lower RP-A501 dose and will no longer use the drug in a pretreatment regimen, believed to have resulted in death.
The company said in Rocket's second quarter 2025 financial results that its cash position was $271.5 million. An infection that may be life-threatening.
Last June, the FDA rejected Kresladi's BLA submission and requested more information on chemistry, manufacturing and control. Rocket said in its quarterly report that it expects to address these issues by the end of 2025. The approval of Kresladi in LAD-I may bring priority review credentials, and Rocket will be able to sell to strengthen its financial position.
Illustration: Akendo, Getty Images
