What was the first cure for sickle cell disease? The journey from accidental discovery to gene therapy

October 1, 2025 •

4 min read

In 1984, an 8-year-old child with sickle cell disease and leukemia received a bone marrow transplant, which unexpectedly cured both conditions. This landmark event provides a fascinating answer to the question of what was the first cure for sickle cell disease?, setting the stage for decades of further research and groundbreaking treatments.

Quick Summary

The first cure for sickle cell disease came from a bone marrow transplant in 1984. Subsequent treatments included symptom-managing drugs like hydroxyurea and blood transfusions. The most recent breakthroughs are gene-editing therapies, offering new hope for a functional cure for many more patients.

Key Points

First Cure Was Accidental: The first patient cured of sickle cell disease was an 8-year-old who received a bone marrow transplant for leukemia in 1984; the sickle cell disease was cured as a side effect.
Early Treatments Managed Symptoms: Before curative options were available, treatments focused on managing the disease, with blood transfusions starting in the 1960s and the use of penicillin prophylaxis becoming standard in 1987.
Hydroxyurea Was First Drug for Symptoms: While not a cure, the anticancer drug hydroxyurea was the first medication proven to reduce painful crises and was FDA-approved for adults with SCD in 1998.
Bone Marrow Transplants Evolved: Initially limited by the need for a matched donor, advancements since the first cure have made transplants from partially matched (haploidentical) donors a possibility for more patients.
Gene Therapies Offer Modern Cure: In late 2023, the FDA approved Casgevy and Lyfgenia, the first gene therapies for SCD, representing a major milestone in providing intentional, targeted cures for the disease.
CRISPR is a new tool for treatment: Casgevy is the first FDA-approved treatment to use CRISPR gene-editing technology, which increases fetal hemoglobin production to prevent sickling.

The accidental first cure: Bone marrow transplant

While sickle cell disease (SCD) was first identified in 1910, a true cure remained elusive for much of the 20th century. The first documented instance of a cure occurred by chance in 1984 at St. Jude Children's Research Hospital. An 8-year-old patient who had both SCD and acute myeloid leukemia underwent a bone marrow transplant (BMT) to treat the leukemia. The BMT, sourced from an HLA-matched sibling, successfully replaced the patient's faulty hematopoietic stem cells with healthy donor cells, and in the process, completely resolved her sickle cell disease.

This unintentional cure was a monumental moment in medical history. It proved that replacing a patient's stem cells could permanently reverse the genetic condition. However, BMT was (and is) not a simple or widely accessible cure. The procedure is high-risk and requires a compatible, often sibling, donor, which is only an option for a small percentage of patients. The toxic conditioning regimen and the risk of graft-versus-host disease (GVHD) also made it a difficult choice, especially for adult patients.

Stepping stones to better treatment

Prior to the widespread availability of curative therapies, medical advances focused on managing the symptoms and complications of SCD. These developments significantly improved patients' quality of life and life expectancy.

Key treatment milestones include:

Blood Transfusions (1960s): Early use of blood transfusions helped manage severe complications associated with sickle cell crises. Regular transfusions were later shown to reduce the risk of stroke in children by 90%.
Penicillin Prophylaxis (1987): Routine administration of penicillin to infants with SCD became standard practice, significantly reducing bacterial infections and mortality rates.
Hydroxyurea (1998): Originally an anticancer drug, a 1995 study found that hydroxyurea reduced painful sickle cell crises by 50% in adults. In 1998, the FDA approved it for adults, and later expanded approval to children. It works by increasing the production of fetal hemoglobin, which doesn't sickle. While not a cure, it remains a cornerstone treatment.

The modern era of cures: Gene and cell therapy

The last decade has witnessed revolutionary progress in addressing SCD at its genetic root, moving from accidental cures to intentional, targeted therapies.

Hematopoietic Stem Cell Transplantation (HSCT): Building on the initial BMT success, advancements have made HSCT more accessible. In 2012, researchers at Johns Hopkins showed that even partially matched (haploidentical) bone marrow transplants could cure some patients. While still carrying risks, this expanded the potential donor pool significantly.
Gene Therapies (2023): In December 2023, the FDA approved the first two cell-based gene therapies for SCD: Casgevy and Lyfgenia. These therapies involve collecting a patient's own stem cells, modifying them in a lab to correct the genetic error, and then reintroducing them into the patient's body following conditioning.
- Casgevy: Uses groundbreaking CRISPR/Cas9 gene-editing technology to reactivate the gene that produces fetal hemoglobin, which is a key advance.
- Lyfgenia: Modifies the patient's own bone marrow to produce healthy red blood cells.
First New York Patient Cured with Lyfgenia (2025): The efficacy of these new therapies was highlighted in March 2025, when a patient on Long Island became the first in New York to be cured using Lyfgenia.

Treatment comparison


Feature	Bone Marrow Transplant (BMT)	Hydroxyurea	Gene Therapies (e.g., Casgevy)
Mechanism	Replaces faulty stem cells with healthy donor cells.	Increases fetal hemoglobin production to prevent sickling.	Edits a patient's own stem cells to correct the genetic defect.
Cure Potential	Yes (can be curative if successful).	No (manages symptoms and complications).	Yes (aims to be curative).
Risks	Significant risks, including GVHD and mortality.	Generally well-tolerated, but can cause side effects.	Newer therapies, with potential long-term risks still under study.
Donor Requirement	Requires a matched (or partially matched) donor.	No donor required.	Uses patient's own cells (autologous), so no donor needed.
Accessibility	Limited by donor availability and suitability of patient.	Widely accessible and a standard treatment.	Highly specialized, expensive, and limited availability.
First Use/Approval	First documented cure in 1984 (incidental); dedicated transplants followed.	Shown effective in 1995; FDA approved for adults in 1998.	FDA approved in 2023.

Milestones in sickle cell treatment

1910: Dr. James Herrick discovers peculiar “sickle-shaped” red blood cells in a patient with severe anemia.
1949: Linus Pauling and colleagues demonstrate that the hemoglobin molecule is defective in SCD patients.
1960s: Blood transfusions begin being used to treat complications.
1984: The first accidental cure via bone marrow transplant is documented at St. Jude.
1986: Penicillin recognized as effective prophylaxis against infection in infants.
1995: Multicenter study confirms Hydroxyurea reduces painful crises.
1998: FDA approves Hydroxyurea for adults with SCD.
2008: Scientists identify BCL11A gene, a key target for gene therapy.
2023: FDA approves Casgevy and Lyfgenia, the first gene therapies for SCD.

Conclusion

The history of finding a cure for sickle cell disease is a testament to persistent scientific inquiry. It began with an accidental discovery in 1984, which proved that a cure was possible. This was followed by decades of developing incremental treatments, such as hydroxyurea, to manage the debilitating symptoms. Today, the field has reached a new frontier with the advent of genetic therapies like Casgevy and Lyfgenia, which offer a targeted and potentially permanent cure for more patients than ever before. This progression from a rare, risky procedure to intentional genetic intervention highlights the incredible pace of modern medical innovation and the ever-growing hope for those living with SCD.

For more information on sickle cell disease research and care, visit the National Heart, Lung, and Blood Institute (NHLBI) website.

Frequently Asked Questions

A bone marrow transplant cures sickle cell disease by replacing the patient's faulty hematopoietic stem cells with healthy ones from a compatible donor. These new, healthy stem cells then produce normal red blood cells, reversing the disease.

Hydroxyurea is a medication that helps by increasing the production of fetal hemoglobin (HbF). Red blood cells containing HbF do not sickle, which reduces the frequency of painful crises and acute chest syndrome in patients.

Casgevy and Lyfgenia are both FDA-approved gene therapies for sickle cell disease. Casgevy uses CRISPR gene editing to activate fetal hemoglobin production, while Lyfgenia modifies the patient's stem cells to produce an anti-sickling form of hemoglobin.

Gene therapy aims to provide a permanent cure by correcting the underlying genetic defect in the patient's own cells. While it is a relatively new treatment, initial results show it can effectively eliminate sickling and reduce or prevent vaso-occlusive events.

The first cure, a bone marrow transplant, was not widely available due to its high risks and the need for a well-matched donor, which is only possible for a small percentage of patients. It also required toxic conditioning, which could be life-threatening.

Sickle cell disease was first described in western medicine in 1910 by Dr. James Herrick, who observed the characteristic sickle-shaped red blood cells under a microscope.

Long-term use of hydroxyurea is generally safe but requires regular blood monitoring to check for potential side effects such as reduced blood counts. Other rare side effects include gastrointestinal discomfort and skin darkening.