Rocket Pharmaceuticals Wins FDA Accelerated Approval for KRESLADI Gene Therapy in Severe LAD-I Kids

Key Points

• FDA accelerated approval granted to KRESLADI (RP-L201), an autologous lentiviral hematopoietic stem cell gene therapy for pediatric patients with severe LAD‑I who lack an HLA‑matched sibling donor, marking Rocket’s first commercial product and the first gene therapy approval for severe LAD‑I.
• The approval was based on sustained increases in neutrophil CD18 and CD11a from an open‑label study—all treated patients were alive and none required allogeneic transplant after 3.6–5.7 years—while labeled risks (serious infections, veno‑occlusive disease, potential insertional oncogenesis) remain and confirmatory post‑marketing data are required for traditional approval.
• Rocket plans a phased launch for an ultra‑rare, roughly single‑digit/year patient population with commercial availability targeted for Q4 2026 and first patient infusions and revenue expected in 2027; the company has the Rare Pediatric Disease PRV and reported ~$188.9M cash, funding operations into Q2 2027 (potentially into 2028 with PRV monetization).

Rocket Pharmaceuticals NASDAQ: RCKT said the U.S. Food and Drug Administration has granted accelerated approval to KRESLADI (RP-L201), a lentiviral vector-based gene therapy for pediatric patients with severe leukocyte adhesion deficiency type I (LAD-I). Company executives described the decision as the first and only gene therapy approval for severe LAD-I and Rocket’s first commercial product approval.

FDA approval and indication details

On the call, Rocket Chief Executive Officer Dr. Gaurav Shah said the approval is significant for patients with an “ultra-rare” pediatric disease marked by recurrent, life-threatening infections and high early childhood mortality without definitive treatment. He also emphasized that the approval demonstrates Rocket’s ability to execute across gene therapy development, including complex manufacturing and regulatory processes.

Chief Science and Gene Therapy Officer Dr. Jonathan Schwartz said KRESLADI is an autologous hematopoietic stem cell-based gene therapy indicated for pediatric patients with severe LAD-I due to biallelic variants in the ITGB2 gene who do not have an available human leukocyte antigen (HLA)-matched sibling donor for allogeneic hematopoietic stem cell transplant.

Schwartz explained that LAD-I is caused by mutations that lead to deficient or absent expression of the CD18 protein on white blood cells, impairing leukocyte adhesion and migration into tissues. KRESLADI is administered as a one-time intravenous infusion following myeloablative conditioning, introducing functional copies of ITGB2 into a patient’s own hematopoietic stem cells to restore CD18 function.

Clinical data supporting accelerated approval

Schwartz said the FDA granted accelerated approval based on increases in neutrophil CD18 and CD11a surface expression, biomarkers indicating restored beta-2 integrin activity and leukocyte function. The approval was supported by an open-label, single-arm international clinical study in pediatric patients with severe LAD-I.

According to Schwartz, neutrophil CD11a expression increased in all treated patients, and CD18 expression increased in all patients in whom it was severely reduced. He said these improvements exceeded pre-specified response criteria and were sustained over extended follow-up. Rocket reported that all treated patients were alive and none required an allogeneic transplant, with 3.6 to 5.7 years of follow-up after treatment.

Schwartz added that measures of gene marking, including vector copy number in peripheral blood cells, remained stable over time, supporting durable engraftment of gene-corrected stem cells. He also cited “supportive clinical observations” including substantial reductions in infection-related complications and hospitalizations relative to the pre-treatment period. Integration site analyses to date showed highly polyclonal gene marking without evidence of clonal dominance, which he said was consistent with the expected safety profile of lentiviral gene therapy.

Schwartz noted that the prescribing information lists key risks including serious infections, veno-occlusive disease, delayed or failed engraftment, hypersensitivity reactions, and the potential for lentiviral insertional oncogenesis requiring long-term monitoring. During Q&A, he said most serious adverse events in the pivotal study were infections occurring during the post-conditioning neutropenia period that resolved, and that one patient experienced veno-occlusive disease. He said the study did not identify engraftment failure, delayed neutrophil or platelet engraftment, hypersensitivity reactions, or evidence of insertional oncogenesis.

Post-marketing requirements and path beyond accelerated approval

Management said continued approval may be contingent on verification and description of clinical benefit in confirmatory efforts consistent with the accelerated approval framework. In response to analyst questions, Rocket said the FDA’s requirements for conversion to traditional approval are based on further follow-up of the ongoing clinical study and evaluation of a subset of patients in a post-marketing registry, rather than a new clinical trial.

Schwartz said the post-marketing data are expected to come from routine clinical management, including survival, transplant status, and flow cytometry results measuring CD11 and CD18 levels.

Commercial strategy, patient population, and launch timing

Chief Commercial Officer Sarbani Chaudhuri characterized severe LAD-I as an ultra-rare condition and said Rocket is planning a phased, execution-focused launch. She cited an estimate that about 25 children are born with LAD-I each year in the U.S., with roughly two-thirds having the severe form. Dr. Shah added that roughly half of severe patients may receive a transplant and about a quarter may have an HLA-matched sibling donor transplant, leading the company to anticipate single-digit numbers of patients treated annually, including long term.

Chaudhuri said Rocket anticipates commercial availability and initiation of patient enrollment beginning in the fourth quarter of 2026, reflecting operational requirements for an ex vivo gene therapy. She said the company expects first patient infusions—and therefore initial product revenue—to occur in 2027, given a vein-to-vein treatment journey of approximately 4–5 months from enrollment to infusion. She said the timeline is driven by individualized patient collection, manufacturing time, and final product release, with payer access potentially adding variability early on.

Rocket said initial availability will be limited to a small number of specialized treatment centers. Chaudhuri said the company expects to have a “handful” of centers activated by the time it is ready for launch and will evaluate expansion over time. She noted that patients are primarily managed through more than 40 primary immunodeficiency specialist centers across the U.S., which she said have established referral networks.

In Q&A, Rocket outlined several launch “gating steps,” including:

• Product supply readiness with external manufacturing partners
• Vein-to-vein operational infrastructure to coordinate collection through infusion
• Onboarding select qualified treatment centers
• Payer engagement to support reimbursement

On pricing, management said it is not providing guidance yet, but referenced ex vivo gene therapies for other monogenic diseases as potential precedents.

Priority review voucher and financial runway

Shah said the approval makes Rocket eligible for a Rare Pediatric Disease Priority Review Voucher (PRV), which he described as a potential source of non-dilutive capital to support the broader pipeline. In Q&A, Shah clarified that with the approval, Rocket has the PRV “in hand.” He also said the company is in active discussions with external parties regarding monetization and intends to evaluate strategic options to enhance financial flexibility.

Rocket reported that as of Dec. 31, 2025, it had approximately $188.9 million in cash, cash equivalents, and investments. Shah said the company expects that capital to fund operations into the second quarter of 2027, and potentially into 2028 with monetization of the PRV or other non-dilutive sources of capital. In response to a question about commercialization spending, management said it plans a “minimal viable launch” for KRESLADI and does not expect to invest heavily in marketing, prioritizing resources for its Danon and other monogenic cardiovascular programs.

Separately, Shah said “Danon patient tracking” remains on course to begin in the first half of 2026. Rocket also said its current focus for KRESLADI is the U.S. market and that it has not made specific plans for non-U.S. patients.

About Rocket Pharmaceuticals NASDAQ: RCKT

Rocket Pharmaceuticals, Inc is a clinical-stage biopharmaceutical company focused on developing gene therapies for rare, inherited pediatric diseases. The company employs a proprietary adeno-associated virus (AAV) and lentiviral vector platform to deliver functional copies of genes in patients with genetic deficiencies. Its programs target a spectrum of disorders, including Fanconi anemia, leukocyte adhesion deficiency type I and Danon disease, with the goal of delivering one-time treatments that address the underlying causes of disease rather than merely managing symptoms.

The company's pipeline comprises multiple product candidates in various stages of development.

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