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About gene therapy

How genetic material can become life-changing therapies

Each of us has genes that provide our bodies with instructions on how to live and grow.

For those with a missing or mutated gene, however, an individual genetic code can lead to uniquely devastating diseases. Because a genetic condition is part of someone’s DNA, many conventional treatments manage symptoms but do not fundamentally change the course of the disease and require chronic lifelong treatment.

Gene therapy may help compensate for that missing or mutated gene, which can stop or reverse disease progression. Gene therapy may also be used to help produce therapeutic proteins that can treat nongenetic conditions, changing the course of more diseases—and more lives.

From genes to gene therapy

DNA is made up of genes. Genes store information and instructions on making different proteins that our bodies need. These proteins determine how our cells grow and develop.

Variations in our genetic codes are normal—while all humans share about 99% of the same genes, it’s the differences that make us who we are. But sometimes genes can mutate or drop out of the genetic code, leading to missing or deficient proteins. This can lead to serious health impacts, including chronic diseases.

Gene therapy offers a way to make up for these missing or deficient proteins by delivering a functional version of the gene responsible for producing these proteins in one of two ways:

  • Ex vivo therapies involve removing cells from the patient’s body, modifying the genetic material inside the cells in a laboratory, and then returning the cells to the body. Before the cells are returned, however, the patient must undergo conditioning, which uses a chemotherapy drug to prepare the body to receive the modified cells.
  • In vivo therapies involve delivering genetic material directly into the patient’s body, often through a one-time injection. It travels to the cells inside a special delivery vehicle called a vector. Vectors use the protein shells of deactivated viruses, called capsids, which are safe to use to transport healthy genes. Once the functional gene is in the right cells, it starts to produce the missing or deficient protein, helping to slow disease progression or reduce symptoms. Spur is focused on in vivo approaches for our gene therapies.

Scientists have been researching gene therapy for more than 50 years, developing new methods and technologies to make safer and more effective therapies. We’re building on these decades of work, optimizing every component to develop the next generation of in vivo gene therapy.

Our approach to gene therapy

From research to commercial treatment

Developing an in vivo gene therapy requires extensive research and rigorous testing before it becomes widely available.

The first step is to discover a connection between a chronic condition and a missing or deficient protein. The protein deficiency may be due to a missing or defective gene, but could also be caused by environmental factors or other disease states. If delivering a functional copy of a gene could help produce the right therapeutic protein and impact disease progression, researchers then work to determine the most effective way for delivering that functional gene into the right cells.

Once a vector is identified, it is extensively tested in in vivo and ex vivo studies to make sure it is safe and effective. If it is, then it moves into clinical trials involving real patients. Regulatory agencies review all data before allowing any human trial to proceed.

Clinical trials start with a small number of patients who receive the lowest dose likely to generate a therapeutic response. As safety and efficacy are confirmed, the focus shifts to finding the right dosage to achieve the desired clinical results, and the number of patients in the trial increases.

Gene therapies must be produced under strict quality controls in exceptionally clean facilities. Living cells are often used to grow the viral vector, followed by purification steps to isolate the vector from the living cells. Once the therapy is formulated, it is aseptically filled into a sterile container for storage and distributed to treatment centers for the patients who need it.

Regulatory agencies carefully review data from the preclinical studies and clinical trials, along with manufacturing process information and long-term monitoring plans. If the product candidate is approved, it can then be a medicine for patients.