Link between Zolgensma gene therapy and tumor risk ‘will change the calculus’

For two decades, researchers debated whether adeno-associated viruses, the small viruses used to deliver new genes to thousands of patients, could, in some cases, cause tumors. This debate is over.

A series of cases this year presented strong evidence that adeno-associated viruses, or AAVs, can cause cancer, forcing researchers and families to weigh the newly confirmed risk against the technology’s lifesaving potential — and, hopefully, determine how to design better therapies in the future.

“It’s going to change the calculus for some patients,” said Sam Mackenzie, a neurologist at the University of Rochester, speaking specifically about spinal muscular atrophy patients.