Friday, Jul 24, 2026 The claims desk. Receipts included. POWERED BY LENZ ↗
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HEALTH

The Claim

The 2021 Frangoul et al. report on CTX001 stated that the sickle cell disease patient had increased fetal hemoglobin and experienced no severe pain crises during approximately 16.6 months of follow-up.

Verified by Lenz ·

The Short Version

The claim matches the 2021 Frangoul et al. report. The paper states that the sickle cell disease patient had increased fetal hemoglobin after CTX001 and experienced no vaso-occlusive episodes during about 16.6 months of follow-up. A minor nuance is that some detailed HbF characterization was reported at a shorter timepoint, but that does not undermine the claim as written.

Caveats

  • The paper’s most detailed fetal hemoglobin characterization is tied to a shorter timepoint than 16.6 months; the claim remains accurate because it only says HbF increased.
  • "Severe pain crises" is a paraphrase of the paper’s term "vaso-occlusive episodes," which is close but not a verbatim quote.
  • This was an early report involving a single sickle cell disease patient, so it should not be read as proof of long-term outcomes for all patients.

The Receipts

  1. CRISPR-Cas9 Gene Editing for Sickle Cell Disease and β-Thalassemia

    N Engl J Med

  2. CRISPR-Cas9 Gene Editing for Sickle Cell Disease and β-Thalassemia

    PubMed

  3. CRISPR-Cas9 to induce fetal hemoglobin for the treatment of sickle cell disease and beta-thalassemia

    PubMed Central

  4. CRISPR-Cas9 Gene Editing for Sickle Cell Disease and β-Thalassemia

    Innovative Genomics Institute

  5. Safety and Efficacy of CTX001 in Patients with Transfusion-Dependent β-Thalassemia and Sickle Cell Disease

    Blood (ASH)

  6. Promising Follow-Up of Trials Using CRISPR-Cas9 for Inherited Blood Disorders

    Hematology Advisor

  7. Sickle Cell Gene Therapy Using CRISPR

    Synthego

  8. CRISPR-Cas9 to induce fetal hemoglobin for the treatment of sickle cell disease and β-thalassemia

    Wiley Online Library

  9. CRISPR-Cas9 Gene Editing for Sickle Cell Disease and β-Thalassemia

    College of American Pathologists (CAP)

  10. Gene Therapy Created with CRISPR Shows Early Promise in Sickle Cell Disease, Beta-Thalassemia

    Inside Precision Medicine

+ 2 more sources — see the full list on Lenz

Filed Under

CTX001Fetal HemoglobinFrangoul Et Al.Sickle Cell Disease

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