Gene therapy concept render

Gene therapy is a medical approach that modifies genes to treat or prevent diseases, with applications in both inherited and acquired genetic conditions.

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Gene therapy involves introducing, removing, or altering genetic material within a patient's cells to treat disease. It differs from conventional therapy by targeting the molecular root of disorders, especially hereditary ones. There are two main categories: somatic gene therapy, affecting only the treated individual, and germline gene therapy, which alters reproductive cells and can be inherited (the latter is banned in many countries due to ethical concerns).

The primary delivery mechanism uses viral vectors, such as adenoviruses or adeno-associated viruses (AAV), modified to be non-pathogenic. Non-viral alternatives include lipid nanoparticles and electroporation. The CRISPR-Cas9 technique, developed in the 2010s, revolutionized the field by enabling precise DNA editing, reducing side effects. Approved examples include Luxturna for retinal dystrophy and Zolgensma for spinal muscular atrophy, both one-time therapies with high costs (around USD 850,000 per patient for Zolgensma).

Despite progress, challenges persist: immune responses to viral vectors, off-target editing, and the need for repeated treatments in some approaches. In Brazil, research by Fiocruz and Hospital Sírio-Libanês explores applications for cancer and rare diseases. The global gene therapy market is projected to surpass USD 30 billion by 2030, focusing on oncology and hemophilia.

Regulation is complex: ANVISA classifies these products as advanced therapy drugs, requiring rigorous clinical trials. In 2023, Brazil approved the first protocols for gene therapy against acute lymphoblastic leukemia using modified CAR-T cells. Accessibility remains the biggest barrier, with treatments often not covered by public or private health insurance.

Frequently Asked Questions

What is gene therapy?

Gene therapy is a technique that modifies genes in cells to treat or cure diseases, either by inserting healthy genes, removing mutations, or activating defense mechanisms. It can be performed in vivo (directly in the patient) or ex vivo (cells modified in the lab and then transplanted).

Which diseases are already treated with gene therapy?

Approved therapies include Luxturna for inherited retinal dystrophy, Zolgensma for spinal muscular atrophy, Kymriah and Yescarta for certain leukemias, and treatments for hemophilia. Clinical trials are ongoing for Alzheimer's, Parkinson's, cystic fibrosis, and muscular dystrophies.

Are there serious side effects?

Yes, including immune reactions to viral vectors, off-target genetic editing (potentially causing cancer), and damage to healthy cells. Protocols require long-term monitoring. However, most adverse events are manageable in specialized centers.