Breakthrough gene therapy for haemophilia: Why this Indian trial saves patients from repeat hospital visits, high costs

Why this study can be a game-changer

An accompanying editorial by Prof Johnny Mahlangu from the University of Witwatersrand points out that this trial addresses some of the challenges seen with other types of gene therapy and has promise as a long-term treatment for haemophilia A. It’s a breakthrough for Indian scientists as it proves that executing studies involving new gene therapy is possible even in resource-constrained settings. Besides, it could become accessible to more patients, including children.

What the researchers did was correct the deficiency of a crucial clotting factor called Factor 8, which is needed to stop bleeding, for instance, from a cut on the skin. Unaddressed, this could lead to excessive bleeding, sometimes even within the tissue itself. Researchers used the body’s own stem cells and added the corrective gene using a genetically modified lentivirus. These modified cells were then transplanted back into the patients, enabling their bodies to produce the clotting protein naturally.

According to Dr Rajeev Jayadevan, co-chairman, National Indian Medical Association Covid Task Force, “This virus has the special ability to insert its genetic material into the human DNA. The prior genetic modifications made sure the virus was harmless and didn’t cause disease in man. These modified stem cells were then reintroduced into the patient’s bone marrow. The treatment worked. The level of the clotting factor increased and the proof of the pudding was that these patients stopped bleeding.”

What the study means for future therapies

“Genes are basically segments of DNA that work like individual instruction manuals. They help the body manufacture certain important proteins. Several diseases such as haemophilia and sickle cell anaemia are due to faulty genes. Using tools like harmless viruses to deliver healthy genes into the human DNA offers hope where traditional treatments fall short. With gene therapy, some seemingly incurable diseases can now be cured,” says Dr Jayadevan.

Before the treatment, participants had an annual bleeding rate of 20 to 120 episodes. That came down to zero after gene therapy. Some temporary side effects were noted and expected, including severe neutropenia (low white blood cell counts) and severe thrombocytopenia (low platelet counts), both resolving within 11 days. Apart from these, there were no side effects, deaths or new inhibitors in the blood.

Currently, there are more than 1.3 lakh haemophilia patients in the country, who get blood infusions at a high cost.