Severe Toxicity Reported in High-Dose AAV Gene Therapy in Animals

Biotech stocks fell in response to the news.

Written byJim Daley
| 2 min read

Register for free to listen to this article
Listen with Speechify
0:00
2:00
Share

ISTOCK, EUGENEONLINE

Researchers reported severe, life-threatening toxicity in nonhuman primates and piglets treated with high-dose, adeno-associated virus (AAV9) gene therapy this Monday (January 29) in Human Gene Therapy. The news caused stocks of several leading biotech companies to tumble.

James Wilson, a molecular biologist at the University of Pennsylvania, and his colleagues found that an AAV9 variant (AAVhu68) used to deliver a human gene to spinal cord motor neurons in rhesus monkeys and piglets resulted in severe toxicity affecting the liver and motor neurons. Symptoms began appearing within five days of administering the gene therapy. One monkey and three piglets had to ...

Interested in reading more?

Become a Member of

The Scientist Logo
Receive full access to more than 35 years of archives, as well as TS Digest, digital editions of The Scientist, feature stories, and much more!
Already a member? Login Here
February 2026

A Stubborn Gene, a Failed Experiment, and a New Path

When experiments refuse to cooperate, you try again and again. For Rafael Najmanovich, the setbacks ultimately pushed him in a new direction.

View this Issue
Human-Relevant In Vitro Models Enable Predictive Drug Discovery

Advancing Drug Discovery with Complex Human In Vitro Models

Stemcell Technologies
Redefining Immunology Through Advanced Technologies

Redefining Immunology Through Advanced Technologies

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Beckman Coulter Logo
Conceptual multicolored vector image of cancer research, depicting various biomedical approaches to cancer therapy

Maximizing Cancer Research Model Systems

bioxcell

Products

Sino Biological Logo

Sino Biological Pioneers Life Sciences Innovation with High-Quality Bioreagents on Inside Business Today with Bill and Guiliana Rancic

Sino Biological Logo

Sino Biological Expands Research Reagent Portfolio to Support Global Nipah Virus Vaccine and Diagnostic Development

Beckman Coulter

Beckman Coulter Life Sciences Partners with Automata to Accelerate AI-Ready Laboratory Automation

Refeyn logo

Refeyn named in the Sunday Times 100 Tech list of the UK’s fastest-growing technology companies