The company co-founder George Church, 63, says he will test the approach on himself if trials of the medicine on King Charles Spaniel dogs go according to plan.
King Charles Spaniels tend to suffer from a heart ailment that kills half the breed by the age of ten.
His research indicates that changes to the genes of simple organisms, such as flies, can double their lifespan.
The aim is to see a result of a subject’s lifespan increase while maintaining a young physical presence.
Mr Church is seen as a “gene editing” pioneer and is also working on an attempt to bring back the wooly mammoth using prehistoric DNA.
His Rejuvenate laboratory is set to publish a report on a technique that extends rodents’ lives by modifying two genes to act on diseases related to ageing, including heart failure and diabetes.
A document obtained by MIT Technology Review dated last June indicates that the start-up tested its gene therapy on four beagles at Tufts Veterinary School, Massachusetts.
Few details of the processes in the drug have emerged, but the MIT Technology Review speculates that it could involve blocking a protein that acts as a “master switch” in the process by which heart valves thicken.
Mr Church told the After On podcast: “We have already done a bunch of trials in mice and we are doing some in dogs and then we’ll move on to humans.”
Speaking at a recent event in Boston, Professor Church said: “Dogs are a market in and of themselves.
“It’s not only a big organism close to humans. It’s something people will pay for, and the FDA [US Food and Drug Administration] process is much faster.
“You don’t want to go to the FDA and say, ‘We extend life by 20 years’. They’d say, ‘Great, come back in 20 years with the data’.”
“We’ll do dog trials, and that’ll be a product, and that’ll pay for scaling up in human trials.”
Professor Church’s laboratory claims it has already received funding from the US Department of Defence to look into the “enhancement” of its military dogs.
But some experts are sceptical of Rejuvenate Bio’s claims, arguing researchers are nowhere near being able to reverse the ageing process in mammals.
Others have warned there could be unintended consequences of pets living longer, including more dogs outliving their owners and ending up in shelters or having to be put down.