Trial Results Show Gene Transfers Reverse Sickle Cell Disease

Lab producing gene therapies (Cincinnati Children’s Medical Center)

4 Dec. 2018. Results from the first 2 participants in a clinical trial show transferring healthy genes to patients with sickle cell disease reverses symptoms of the disease that continues for up to 1 year. Findings from the clinical trial, which also show the safety and feasibility of the treatments, were presented yesterday at the annual meeting of American Society of Hematology in San Diego.

Researchers led by hematologist Punam Malik at Cincinnati Children’s Medical Center in Ohio are seeking better treatment options for people with sickle cell disease, a genetic blood disorder affecting hemoglobin, a protein in blood that delivers oxygen to cells in the body. People with sickle cell disease have hemoglobin molecules that cause blood cells to form into an atypical crescent or sickle shape. That abnormal shape causes the blood cells to break down, lose flexibility, and accumulate in tiny capillaries, leading to anemia and periodic painful episodes. Sickle cell disease is prevalent worldwide, and affects 70,000 to 80,000 people in the U.S., including about 1 in 500 people of African descent.

Research by Malik and others found people with sickle cell disease have a malfunctioning gene that switches off production of healthy fetal hemoglobin, even well into adulthood. Their therapy delivers a modified healthy fetal hemoglobin gene with a benign virus to the patient’s blood-forming stem cells taken from bone marrow. The stem cells are cultured and transformed into healthy blood-forming cells with functioning genes producing fetal hemoglobin, later transplanted back into the patient.

The researchers say their process requires less preconditioning of bone marrow with chemotherapy than most other bone marrow transplants, allowing for recovery of healthy blood counts within 10 days, reducing risks of infections. The early- and mid-stage clinical trial is testing the gene therapy among 10 adult participants with sickle cell disease, also known as sickle cell anemia, or SCA. The study is assessing the feasibility of the process for 1 year, and safety of the treatments for as long as 15 years.

Before the trial, the study’s first 2 participants, age 35 and 25, experienced pain crises 5 or more times per year, often requiring hospitalization and opioid pain relievers. Findings from the trial’s first participant show after 1 year, the individual reports only a single acute sickle cell event, with near elimination of chronic pain and no further need for daily opioid pain relievers. The second participant reports fewer pain crises and decreasing need for pain drugs in the 6 months following treatment.

“Although it’s still early post-treatment,” says Malik, director of the hospital’s sickle cell disease center, in a Cincinnati Children’s statement, “these preliminary results are quite promising. If sustained this therapy will provide a transportable, safe, and feasible gene therapy for all SCA patients.”

As reported recently in Science & Enterprise, Malik’s research on sickle cell disease is licensed to the start-up enterprise Aruvant Sciences, in a joint venture between Cincinnati Children’s and Roivant Sciences, a Swiss medical technologies company. Aruvant Sciences is commercializing Malik’s gene therapy for sickle cell disease, code-named RVT-1801. The new company also plans to test the gene therapy as a treatment for beta-thalassemia, an inherited disorder where individuals have lower production of hemoglobin in their blood.

More from Science & Enterprise:

• Biotechs Collaborate on More Precise Gene, Cell Cancer Therapies
• FDA Issues Draft Gene Therapy Regulatory Guidance
• Gene Therapy Shown to Reduce Extreme High Cholesterol
• Long-Term Effects Shown from Hemophilia Gene Therapy
• Gene Therapy Safety Study for Heart Failure Underway

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