Rocket aborts FDA filing for Fanconi gene therapy

Rocket Pharma has revealed it is withdrawing its marketing application in the US for RP-L102, its experimental gene therapy for Fanconi anaemia (FA), shortly after also pulling it in the EU.

The company revealed its decision in a financial filing (PDF) today, noting that it follows a previously announced restructuring to focus on "programmes with the clearest regulatory and commercial pathways."

The company said it had made the move because of "business and strategic considerations" adding that it does not reflect concerns regarding the safety or efficacy profile of RP-L102, also known as Fanskya and mozafancogene autotemcel. It will no longer invest any resources in the programme, but said it would consider partnering with another group that would be prepared to take it forward.

"Withdrawal of the [biologics license application] preserves Rocket's ability to re-engage with regulators at a later date should there be an appropriate strategic or partnership pathway to sustainably progress the programme," said the company.

FA is an inherited syndrome that impairs the body's chromosomal repair systems, causing the bone marrow to lose its ability to produce enough healthy blood cells. It causes anaemia and risk of infections and bleeding, and can result in organ malformations and an increased risk of cancers.

There are several different subtypes, with the type A form targeted by RP-L102 the most common and caused by mutations in the FANCA gene. The therapy is based on stem cells harvested from FA patients' peripheral blood that are modified with a lentiviral vector to contain a functional copy of FANCA.

RP-L102 had been trumpeted as the first alternative to allogeneic haematological stem cell transplantation (HSCT), which is associated with significant toxicities due to the need for a cytotoxic conditioning regimen to clear the way for the donor cells to colonise the bone marrow.

With RP-L102 shelved, Rocket is focusing its attention on Kresladi (marnetegragene autotemcel) for the treatment of severe leukocyte adhesion deficiency-I (LAD-I), which was turned down by the FDA but set to be refiled later this year, and recently announced it would slash its headcount by 30% and focus exclusively on gene therapies delivered via its AAV technology.

Those include RP-A501 for Danon disease – in phase 2 but currently under an FDA clinical hold while a serious adverse event leading to a patient death is investigated – along with RP-A601 for PKP2 arrhythmogenic cardiomyopathy and RP-A701 for BAG3-associated dilated cardiomyopathy, both in phase 1.

Photo by Roland Horváth on Unsplash