Gene Therapy for Sickle Cell Disease: Practice Recommendations from the American Society for Transplantation and Cellular Therapy and the International Society for Cell & Gene Therapy.
Published by American Society for Transplantation and Cellular Therapy and the International Society for Cell & Gene Therapy
Summary
AI-generatedGene therapy has emerged as a transformative treatment option for individuals with sickle cell disease (SCD). However, the complexity of patient selection, stem cell mobilization, manufacturing, conditioning, and long-term follow-up underscores the need for standardized, evidence-informed clinical guidance to support shared decision-making and promote safe care delivery.
Key Takeaways
- 1Gene therapy requires a multidisciplinary evaluation and capacity for long-term follow-up.
- 2Patient selection involves evaluating not just genetics, but also social context, organ function, and reproductive goals.
- 3Plerixafor-only mobilization is recommended; G-CSF is contraindicated.
- 4Automated red cell exchange prior to mobilization and conditioning is essential to mitigate complications.
- 5Myeloablative busulfan conditioning requires pharmacokinetic-guided dosing and proactive toxicity management.
- 6Early fertility preservation counseling is imperative as current conditionings are gonadotoxic.
- 7Lifelong surveillance is mandatory to monitor for late effects of conditioning, insertional mutagenesis, and evolving end-organ damage.
Key Recommendations
Table 2. A summary of the key recommendations
- rec-1
Gene therapy for SCD requires multidisciplinary evaluation, integrating care by hematology, transplant, transfusion medicine, reproductive health, mental health, and social service providers to ensure patients can safely complete the full treatment pathway.
Management - rec-2
Patient selection should extend beyond genotype and disease severity, incorporating organ function, comorbidities, reproductive goals, psychosocial context, and capacity for long-term follow-up.
Assessment - rec-3
Plerixafor-only mobilization is recommended, with granulocyte colony-stimulating factor contraindicated due to safety concerns in SCD.
Treatment - rec-4
Automated red cell exchange before mobilization and conditioning is essential to reduce hemoglobin S levels and minimize peri-procedural complications.
Prevention - rec-5
Myeloablative busulfan conditioning remains standard, requiring pharmacokinetic-guided dosing and proactive management of toxicity, fertility risk, and infection.
Treatment - rec-6
Fertility preservation counseling and intervention should occur early, as current gene therapy approaches are gonadotoxic and do not alter genetic transmission risk.
Counseling - rec-7
Long-term, lifelong surveillance is mandatory, addressing late effects of conditioning, risks related to gene modification, and the evolution of SCD-related organ damage.
Monitoring - rec-8
Participation in national and international registries is strongly encouraged to define durability, late toxicities, and real-world effectiveness of gene therapies.
Monitoring
Scope & Objectives
Clinical Topic
Sickle Cell Disease
Objectives
To provide standardized, evidence-informed practical recommendations for the clinical implementation of ex vivo gene therapies for sickle cell disease.
Target Patient Population
Individuals with severe sickle cell disease
Target Providers
Patient Criteria & Setting
Therapeutic Area
HematologyGuideline Scope
Inclusion Criteria
- HbSS or HbS β0-thalassemia genotypes
- Age 12 to 45 years
- At least two hospital encounters for VOEs requiring opioids in each of the 2 years preceding gene therapy OR four VOEs in the 24 months before enrollment
Exclusion Criteria
- Two or more α-globin deletions (for β-globin gene addition therapy)
- History of stroke or abnormal transcranial Doppler imaging
- Cancer
- Active viral or fungal infections
- Significant iron overload associated with liver fibrosis
Care Settings
Special Populations
Safety & Contraindications
Contraindications
- Granulocyte colony-stimulating factor (G-CSF) for stem cell mobilization
Monitoring Guidance
Annual surveillance beginning 1-2 years after treatment and lasting up to 15 years, conceptualized across late effects of conditioning, risks related to gene modification (insertional mutagenesis), and evolution of SCD-related organ damage.
Authors & Contributors
Guideline Features
Learning Context
Difficulty
advanced
Learning Paths