To startup founder and Stanford Medical graduate Jesse Karmazin, blood is the next big government-approved drug.

Karmazin recently launched Ambrosia Medical – a startup that fills the veins of older people with fresh blood from young donors – in the hopes that the procedure will help conquer ageing by rejuvenating the body's organs.

The company plans to open its first clinic in New York City by the end of this year, Karmazin told Business Insider.

In 2017, Ambrosia enrolled people in the first US clinical trial designed to find out what happens when the veins of adults are filled with blood from the young.

While the results of that study have not yet been made public, Karmazin told Business Insider the results were "really positive."

Because blood transfusions are already approved by the Food and Drug Administration, Ambrosia's approach has the green-light to continue as an off-label treatment.

There appears to be significant interest: since putting up its website last week, the company has received roughly 100 inquiries about how to get the treatment, David Cavalier, Ambrosia's chief operating officer, told Business Insider.

That led to the creation of the company's first waiting list, Cavalier said.

"So many people were reaching out to us that we wanted to make a simple way for them to be added to the list," Cavalier said.

With that in mind, Cavalier and Karmazin are currently scouting a number of potential clinic locations in New York City and organising talks with potential investors. They hope to open the facility by the end of this year.

"New York would be the flagship location," Karmazin said.

The first clinical trial of its kind

Because blood tranfusions are already approved by federal regulators, Ambrosia does not need to demonstrate that its treatment carries significant benefits before offering it to customers.

So far, the company has already infused close to 150 patients ranging in age from 35 to 92 with the blood of young donors, Cavalier said. Of those, 81 were participants in their clinical trial.

The trial, which involved giving patients 1.5 litres (1.58 quarts) of plasma from a donor between the ages of 16 and 25 over two days, was conducted with physician David Wright, who owns a private intravenous-therapy center in Monterey, California.

Before and after the infusions, participants' blood was tested for a handful of biomarkers, or measurable biological substances and processes that are thought to provide a snapshot of health and disease.

People in the trial paid US$8,000 to participate. The company hasn't settled on a commercial pricetag for the procedure, Karmazin said.

"The trial was an investigational study. We saw some interesting things and we do plan to publish that data. And we want to begin to open clinics where the treatment will be made available," Cavalier said.

Karmazin added that the trial showed the treatment to be very safe.

"The safety profile was essentially perfect, or as good as plasma transfusions are," Karmazin said.

Young blood and anti-ageing: Are there any benefits?

Karmazin is right about the safety of blood transfusions and their capacity to save lives.

A simple blood transfusion, which involves hooking up an IV and pumping the plasma of a healthy person into the veins of someone who's undergone surgery or been in a car crash, for example, is one of the safest life-saving procedures available.

Every year in the US, nurses perform about 14.6 million of them, which means about 40,000 blood transfusions happen on any given day.

But as far as young blood is concerned – and its alleged potential to fight ageing – the science remains unclear.

"There's just no clinical evidence [that the treatment will be beneficial], and you're basically abusing people's trust and the public excitement around this," Stanford University neuroscientist Tony Wyss-Coray, who led a 2014 study of young plasma in mice, recently told Science magazine.

Karmazin is still optimistic. He got the idea for his company as a medical student at Stanford and an intern at the National Institute on Ageing, where he watched dozens of traditional blood transfusions performed safely.

"Some patients got young blood and others got older blood, and I was able to do some statistics on it, and the results looked really awesome," Karmazin told Business Insider last year.

"And I thought, this is the kind of therapy that I'd want to be available to me."

So far, no one knows if young blood transfusions can be reliably linked to a single health benefit in people.

Karmazin said "many" of the roughly 150 people who've received the treatment have noted benefits that include renewed focus, better memory and sleep, and improved appearance and muscle tone.

But it's tough to quantify these benefits before the study findings are made public. There's also the possibility that simply travelling to a lab in Monterey and paying to enroll in the study could have made patients feel better.

Studies in mice don't necessarily translate to results in people

Karmazin was inspired to create his blood infusion treatment after seeing seeing several mouse studies that involve parabiosis, a 150-year-old surgical technique that connects the veins of two living animals. (The word comes from the Greek words para, or "beside," and bio, or "life.")

Irina Conboy, a bioengineering professor at the University of California at Berkeley who pioneered one of these parabiosis studies in mice in 2005, found evidence that the exchange had done something positive for the health of the older mouse who received the blood of the younger mouse.

But the animals weren't simply swapping blood – the older rodent was also reaping the benefits of the younger one's more vibrant internal organs and circulatory system.

In other words, the researchers couldn't say for sure whether it was the blood itself that was doing the apparent reviving or if the fact that the animals were linked in other ways was responsible for those perceived benefits.

In 2016, Conboy and her team ran another study to see what would happen if they merely exchanged the rodents' blood without connecting their bodies in any way.

They found that while the muscle tissue in the older mice appeared to benefit slightly from the younger blood, they still couldn't say for sure that these modest benefits were coming from the young blood itself.

After all, the experiment had also fundamentally changed the older mouse blood by diluting it.

"The effects of young blood on old tissue seems to be rejuvenating; however, there is no concrete evidence that young blood is what is causing the change in results. It may very well be the dilution of old blood," Ranveer Gathwala, a UC Berkeley stem-cell researcher in Conboy's lab who co-authored the 2016 paper, previously told Business Insider.

Nevertheless, Karmazin remains hopeful that the benefits he said he's witnessing are the result of young blood transfusions.

"I'm really happy with the results we're seeing," he said.

This article was originally published by Business Insider.

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