Breakthrough bone marrow treatment can cure sickle cell disease

Sickle cell disease (SCD), the most common inherited blood disorder, affects millions worldwide. In the United States alone, it impacts over 100,000 individuals, predominantly African Americans.

The disease arises from a genetic mutation that alters red blood cell shape, making them rigid and crescent-like. These abnormal cells obstruct blood vessels, leading to severe pain episodes, organ damage, and increased risk of stroke. While treatments have improved childhood survival, adults continue to face significant health risks and early mortality.

The median life expectancy for individuals with SCD remains around 48 years, a figure that has remained largely unchanged for decades. However, recent advances in medical science offer hope.

Two newly approved gene therapies and a refined bone marrow transplantation technique present potential cures. Yet, the debate over accessibility, cost, and long-term risks continues to shape the future of SCD treatment.

The research findings were recently published in the journal Blood Advances.

For many years, disease management relied on medications like hydroxyurea and blood transfusions. These treatments reduce complications but do not eliminate the disease.

Gene therapy, a breakthrough in medical science, offers a path to potentially eliminating SCD at its root. The process involves extracting a patient’s stem cells, modifying them to produce healthy hemoglobin, and reinfusing them into the body. This approach aims to replace defective blood cells with properly functioning ones.

While promising, gene therapy has limitations. The treatment requires intense chemotherapy to eliminate diseased cells before introducing the modified ones. This preconditioning process is highly toxic and excludes many individuals with SCD who already suffer from severe organ damage.

Additionally, the procedure is expensive. Estimates suggest the total cost ranges from $2 million to $3 million per patient. The extended hospital stay—often between six and eight weeks—adds to the financial burden.

Dr. Richard Jones, professor of oncology at Johns Hopkins, highlights a crucial concern: “Many people—and maybe most adults—aren’t eligible for gene therapy because of the requirement for high-dose chemotherapy that people with end organ damage can’t receive.”

Furthermore, he warns that long-term effects could include organ damage and an increased risk of leukemia. While gene therapy remains a groundbreaking approach, it is neither universally accessible nor without significant risks.

Another treatment option gaining attention is bone marrow transplantation, specifically reduced-intensity haploidentical transplantation. This method uses a donor whose tissue matches at least half of the recipient’s immune proteins. Unlike traditional transplants that require a perfect match, this technique significantly expands the donor pool to include parents, siblings, children, nieces, nephews, and cousins.

Before the transplant, patients receive low-dose chemotherapy and radiation to prepare their bodies. Afterward, they are given cyclophosphamide, a drug that prevents graft-versus-host disease (GVHD), where the transplanted cells attack the recipient’s body. The results have been remarkable.

A multi-center clinical trial led by Johns Hopkins found that 95% of the 42 participants survived at least two years post-transplant, and 88% were considered cured, experiencing no disease-related events. The median follow-up period was 37 months, demonstrating long-term effectiveness.

Dr. Robert Brodsky, director of hematology at Johns Hopkins, emphasizes that transplantation is “a far less costly option for medical centers and patients.”

The procedure typically requires an eight-day hospital stay, compared to weeks for gene therapy. Additionally, the median number of transfusions needed post-transplant is six, while gene therapy patients require around 50.

The cost is also significantly lower. A bone marrow transplant costs roughly $467,747—about five times less than gene therapy. Beyond affordability, the treatment is more accessible. Most individuals with SCD qualify, and the risks are well understood. Moderate to severe GVHD occurred in 22% of transplant recipients, but severe complications were rare. Two patients died within a year of the procedure, one from COVID-19.

Despite its success, many in the medical community mistakenly believe that transplantation requires a perfect donor match. Historically, finding a fully compatible donor limited its availability. The reduced-intensity haploidentical approach overcomes this obstacle by allowing half-matched donors. This expansion dramatically increases the number of eligible patients.

Another common fear is the risk of severe GVHD and transplant rejection. However, the trial’s findings show otherwise. By using post-transplant cyclophosphamide, doctors significantly reduced GVHD rates while maintaining high survival outcomes.

Dr. Jones emphasizes, “Our results with allogeneic transplant are every bit as good as or better than what you see with gene therapy.”

Transplantation also sidesteps the risks associated with gene therapy’s chemotherapy conditioning. Patients with advanced organ damage, who would be ineligible for gene therapy, can often undergo bone marrow transplants safely. The procedure’s lower toxicity makes it a preferable choice for many adults with SCD.

With these promising options available, the next challenge is ensuring access. Gene therapy, despite its groundbreaking potential, remains limited by cost and eligibility. Transplantation, on the other hand, provides an effective, affordable, and more accessible alternative. As research advances, further refining these treatments will be critical to improving outcomes.

Expanding awareness among patients and healthcare providers is crucial. Many adults with SCD continue to endure pain and organ damage without realizing a curative option exists. Greater investment in donor registries and insurance coverage for transplantation could increase accessibility and improve quality of life for thousands.

While no single solution fits all, bone marrow transplantation is emerging as a leading contender for curing SCD. As medical institutions adopt reduced-intensity haploidentical transplantation, the potential to transform lives grows. For the millions affected by SCD, these advances offer real hope for a healthier future.

Note: Materials provided above by The Brighter Side of News. Content may be edited for style and length.

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