The Past and Future of Gene Therapy

The FDA approved the first gene therapy in 2017, marking a significant moment in the history of health care. Since tisagenlecleucel (Kymriah) was approved for refractory B-cell precursor acute lymphoblastic leukemia, the FDA subsequently approved axicabtagene ciloleucel (Yescarta) for diffuse large B-cell lymphoma and Luxturna (voretigene neparvovec-rzyl) for a rare vision loss disease.

These approvals followed decades of both successful and unsuccessful research, according to a review of the history of gene therapy published by Science.

The review article also examines the future of the groundbreaking approach, including the promise of CRISPR/Cas9 gene-editing technology. These strategies could result in better and more effective gene therapies for various conditions, according to the authors.

According to the study, the best approaches to gene therapy include:

· Direct in vivo administration of viruses to deliver therapeutic genes.

· Transfer of engineered blood or bone marrow stem cells from the patient, to modification, and injected back into the patient.

Despite the current promise of direct administration of viral vectors, early clinical trials in the 1990s exposed patients to toxicities, including inflammatory responses and malignancies, according to the article. However, this setback resulted in more in-depth research, which the authors said ultimately led to the success of the treatment.

Although gene therapy was originally viewed as a treatment for inherited conditions, it is now being evaluated as a treatment for multiple cancers, HIV, and other potentially life-threatening conditions.

In addition to the first FDA approvals, numerous positive clinical trials for gene therapy emerged in 2017. These treatments have shown promise for hemophilia, sickle cell disease, blindness, neurodegenerative diseases, genetic diseases, and cancers of the bone marrow and lymph nodes, according to the study.

“The ability of gene therapies to provide durable benefits to human health, exemplified by the scientific advances and clinical successes over the past several years, justifies continued optimism and increasing efforts toward making these therapies part of our standard treatment armamentarium for human disease,” the authors wrote.