The FDA granted accelerated approval to Rocket Pharmaceuticals’ gene therapy Kresladi (marnetegragene autotemcel) for severe leukocyte adhesion deficiency-I (LAD-I), the first gene therapy option for the ultrarare immune disorder. The decision clears Kresladi for pediatric patients with severe LAD-I due to biallelic variants in ITGB2 who lack an HLA-matched sibling donor. The approval follows an earlier FDA rejection tied to manufacturing issues in 2024. With an April 2026 PDUFA date already in view for the original review path, Rocket’s resubmission and manufacturing remediation appear to have closed the regulatory gaps, enabling the accelerated pathway. For developers and investors watching rare-disease gene therapy, the key takeaway is that FDA’s manufacturing scrutiny—rather than efficacy alone—can still be decisive late in the process, even for first-in-category programs.