One-Shot Gene Editing for Cholesterol Is Closer, but Doctors Urge Caution

A single gene-editing treatment might someday keep cholesterol in check for decades and replace daily pills. Two University of Michigan cardiologists warn that permanent changes to a person's genes carry risks that may take years to show up, especially if millions of people receive them.

The warning comes in a perspective piece in JAMA Internal Medicine by Eric D. Smith and Venkatesh L. Murthy of the University of Michigan Health Frankel Cardiovascular Center, according to a Michigan Medicine summary published by ScienceDaily on Nov. 3. It is an expert commentary on how to weigh benefits and risks, not a new clinical trial.

What is a "one-and-done" gene therapy?

Gene therapies can add working copies of a gene, silence harmful genetic activity or edit DNA directly. Ordinary medicines generally work only while a patient keeps taking them. Some genetic treatments are designed to work after one dose, which is why they are often called "one-and-done."

The authors note that a single treatment does not guarantee a lifetime of benefit. Many gene therapies use modified viruses to carry genetic instructions into cells, and the immune system can learn to recognize those carriers. Smith explained that repeating the treatment may then be difficult or impossible, even if its effects fade.

Where does gene therapy already work?

More than 6,000 rare genetic disorders have been identified, though only a small share currently have targets that therapies can reach. Gene therapies have already had important successes against spinal muscular atrophy and sickle cell disease, according to the summary.

Current treatments generally target somatic cells, meaning body cells not involved in reproduction. They are not meant to create changes that could be passed to future generations, unlike germline editing.

Why are common diseases a different case?

For people with rare and devastating conditions, the authors say the benefits may clearly outweigh the dangers, particularly when few treatments exist. High cholesterol, heart disease, obesity and diabetes are different because established treatments already exist.

Many of those medications can be adjusted as a patient's condition changes or stopped if side effects appear. A permanent genetic change may not allow that. Murthy also pointed to scale: a side effect that is rare could still harm many people if a therapy goes to millions, so treatments meant for wide use must meet especially demanding safety standards.

What five questions do the authors propose?

Smith and Murthy suggest weighing five factors before using genomic therapy:

• Disease severity: how serious the condition is and how much patients could benefit.
• Existing treatments: whether effective therapies already exist that can be adjusted or stopped.
• Treatment durability: whether the targeted tissue suits an intervention meant to last after one dose.
• Delivery risks: whether the dangers of delivering the treatment are reasonable given the disease.
• Long-term monitoring: whether researchers can reliably track safety and effectiveness over many years, especially with large numbers of patients.

The authors describe the last question as potentially the hardest. Clinical trials usually involve relatively small groups followed for limited periods. They can catch many safety problems but may miss extremely rare complications or ones that take years to develop, and some effects might only emerge once a treatment reaches a much larger population.

Why does it matter for patients?

The prospect of replacing lifelong medication for common conditions is appealing, and researchers are exploring it for high cholesterol, heart disease, obesity and diabetes. The commentary suggests that for these widespread conditions, a one-time fix would be judged more strictly than a treatment for a rare disease with no alternatives.

In practice, the authors' framework implies that existing, adjustable drugs set a high bar. A permanent therapy would have to show that its benefits justify losing the option of changing course, and that its safety can be followed for years after people receive it. The summary does not describe any specific cholesterol gene-editing product or give a timeline for when such treatments might be offered broadly.

Around Prague, based on reporting by ScienceDaily