Embryo - organ harvesting

 

With plans to create realistic synthetic embryos, grown in jars, Renewal Bio is on a journey to the horizon of science and ethics.

“If you look around, all the trials are at an early stage. Not all are likely to produce cures, but they will give us information on how to improve and how to refine things,” says Pera.

For transplanted cells, one open question that can be answered only through experiments on people is how long those cells will survive. When dopamine-making neurons are added to the brains of Parkinson’s patients, something that’s been tried a few times, most of those neurons end up dying. Researchers have gone back to the drawing board, trying to figure out why, and how to adjust their tactics. Maybe they just need to crank up the dose, despite possible risks—too much dopamine is almost as bad as too little, and it can cause involuntary movements. The Vertex study on diabetes, which is expected to treat 40 people, looks more promising, but there too it remains unclear how long the added cells will live. It means a very costly treatment (some estimate a cell transplant for diabetes will run at least $500,000) might not be forever. 

Yet Loring is hopeful that one of these tests will soon lead to striking, incontrovertible proof that treatments crafted from embryonic stem cells can cure disease. “It could be the tipping point,” she says. “And I do think we need that moment.” 

Epilepsy treatment

During the three days I spent at the gathering of stem-cell researchers, one study stood out to me as looking like the big breakthrough this field needs. It’s a new trial being run by a biotech called Neurona Therapeutics, in San Francisco, which a year ago transplanted lab-made “inhibitory interneurons” deep into the brains of two people whose intractable epilepsy wasn’t responding to ordinary drugs. The bet is that these added cells will each form thousands of connections and quiet the malfunctioning brain networks that cause seizures.

During the meeting, Neurona announced that both patients have seen a 90%-plus reduction in seizures. In the case of one 26-year-old-man, that’s down from a debilitating 32 seizures a month. If the data holds up, it could mean the cell transplant is as effective as the most drastic treatment available for epilepsy today, which is surgical removal of part of the temporal lobe. But it wouldn’t have the side effects of getting part of your brain removed, like lost memories and vision. 

“There’s a lot of enthusiasm. This could be the first cell therapy for epilepsy,” says Kriegstein, the professor at the University of California, San Francisco, who is also an adviser to Neurona and its cofounder. Kriegstein told me he doesn’t think 25 years is a long time for this type of therapy to emerge. Instead, he counters, it’s “actually kind of fast.”

“There’s a lot of enthusiasm. This could be the first cell therapy for epilepsy.”

-Arnold Kriegstein

Doctors had experimented with neuron grafts before—one company tried using cells from pigs. But it was Cory Nicholas, a postdoctoral fellow in Kriegstein’s lab, who first determined, in 2013, how embryonic stem cells might be coaxed towards forming human interneurons in large quantities. What followed was what Kriegstein calls a series of “rational, systematic” steps over a decade to improve that recipe, run tests on animals, and win approval to start a human trial. Most of that work was done at Neurona, which has raised over $160 million and where Nicholas is CEO. 

 “Obviously, this wouldn’t be possible without embryonic [or induced] stem cells,” says Kriegstein. 

With only two patients treated, Neurona’s results remain anecdotal. But there’s a chance it’s an actual cure. That’s because the transplanted cells are likely still forming connections, and their effect may increase with time, possibly preventing seizures altogether. “It did seem like a pipe dream at first, but being able to make these cells in unlimited numbers is what let us try. Now we have patients who’ve been helped. It’s really quite amazing when you think about it,” says Kriegstein. “We are in the clinic. Cells are in patients, and we are going to see now how well they work. We are right at the point that the clinical trials will give us some clues. Was it just hype, or is it real?”