One-time gene therapy added 24 percent to mouse lifespan

Researchers at the Spanish National Cancer Research Centre in Madrid tested whether a single dose of telomerase gene therapy could still help, delivered to already adult and aging mice rather than to embryos.

The team injected a virus carrying the telomerase gene into mice that were one year and two years old. Mice treated at one year lived a median of 24 percent longer, and those treated at two years lived 13 percent longer, with better insulin sensitivity, bone density and muscle coordination along the way.

None of the treated mice developed more cancer than untreated littermates, and an inactive version of the enzyme produced no benefit, confirming functioning telomerase itself was doing the work. The therapy was a single dose through a virus with broad tissue reach rather than a repeated drug. Translating a one-time gene therapy like this into people would require far longer safety monitoring than this study provided.

One treatment, a quarter more lifespan.