At 50 days old, mice with advanced Leigh syndrome were given a new two-drug combo — and lived more than twice as long as expected, reaching 158 days. This striking result came from a study at the Broad Institute of MIT and Harvard, where scientists are turning the idea of 'low-oxygen therapy' into a potential pill. For years, researchers led by Vamsi Mootha had noticed something unusual: mice with neurodegenerative diseases like Parkinson’s and rare mitochondrial disorders improved when exposed to low-oxygen air, similar to high-altitude conditions. Now, they’ve found a way to mimic that effect without requiring mice — or, one day, people — to live on a mountain.
The treatment targets a hidden problem in many brain diseases: too much unused oxygen in tissues. When mitochondria, the cell’s power plants, don’t work properly, oxygen builds up and can damage neurons. The new drug combo, called a 'hypoxia-in-a-pill,' uses two small molecules to safely reduce oxygen delivery to cells. One, GBT601, binds to hemoglobin in red blood cells and keeps it from releasing oxygen into tissues. The other, PT2399, stops the body from overcompensating by making more red blood cells. Both drugs are based on existing, FDA-approved compounds and have already been tested for safety in healthy human volunteers.
In mice with Parkinson’s disease, the treatment reversed movement problems — even in advanced stages — matching the benefits seen when mice breathe air with just 11% oxygen, like at 15,000 feet above sea level. In Friedreich’s ataxia mice, the combo stopped the disease from getting worse, though it didn’t reverse existing symptoms. But the biggest leap was in Leigh syndrome mice, where lifespan more than doubled. These disorders, though rare, share a root cause: broken mitochondria. And because mitochondrial dysfunction also plays a role in aging and common diseases like Parkinson’s, the implications go far beyond these models.
The findings, published in the Proceedings of the National Academy of Sciences, offer real hope for future therapies. Mootha, who is also a professor at Harvard Medical School and an investigator at Massachusetts General Hospital, sees this as a turning point. The drugs are not yet ready for human trials in these diseases, but the path forward is clearer. If future studies confirm the benefits in people, a simple pill could one day help millions living with neurodegenerative conditions. As Mootha puts it, 'We're excited by the prospects of a hypoxia pill that may benefit Parkinson's patients.' For now, the science is still in mice — but the air of possibility is growing thinner in all the right ways.