Months after $10M Series A, rare disease AI upstart Healx hauls in $56M in fresh funding
In 2010, Nick Sireau quit his job to focus solely on the patient group he had set up to help his sons diagnosed with a rare genetic disease called alkaptonuria (AKU). Researchers had found a feasible treatment from an unlikely source: a weedkiller, but it was being used to help infants with a different disorder. Sireau would then confront the perils of the traditional trial-and-error drug discovery process that demands time and money.

In 2014, two scientists met Sireau, who had been fiercely lobbying and fundraising to get UK authorities to trial the compound in patients with AKU. The encounter sparked the two researchers — the British scientist behind Viagra, David Brown, and a bioengineer from Cambridge, Tim Guilliams — to work on marrying the concept of drug repurposing with AI and machine learning, particularly for rare conditions. Soon, their company — Healx — was born.
This July, the Cambridge, UK-based company raised $10 million in a Series A round of funding. On Wednesday, Healx unveiled a fresh $56 million injection — as it preps for a Phase IIa clinical trial expected to initiate in the first quarter of 2020 — in patients with Fragile X syndrome, a condition that spawns developmental problems and is considered the leading genetic cause of autism.
The trial will evaluate the safety and efficacy of a combination therapy, Guilliams told Endpoints News, declining to provide further detail.
“If you look at combinations of two or three drugs, you have about 13 billion possibilities per disease — so how do you select the top 10, the top 20? And we don’t go beyond that,” Guilliams said. Healx’s AI platform claims to shorten the discovery-to-clinic timeline to as little as 24 months.

Healx’s approach does not lean on an initial hypothesis. “We let the algorithm decide which diseases we’re going to work on, which drugs are being matched. And then we work out a mechanism or hypothesis afterwards,” he said.
So far, Healx has launched 10 preclinical programs across a plethora of indications — of which four (including the Fragile X program) have reaped results so far, Guilliams said, noting that each of these readouts has been positive. With this Series B, the plan is to launch another 40 preclinical programs, he added.
If they are successful — with any of these shots on goal — the plan is to make sure pricing is not in the typical orphan drug price range which hovers around $240,000 per patient per year, Guilliams said.
Repurposing drugs on purpose (or by accident) has yielded some success — that the process involves largely de-risked compounds, lower developmental costs, and briefer timelines doesn’t hurt either.
Viagra is, of course, the most heavily cited example. The drug, known chemically as sildenafil, was originally being tested as a treatment for coronary hypertension — but a pesky side effect felt by patients in trials led to its eventual approval as an erectile dysfunction drug.
Then there’s the sedative thalidomide — which gained notoriety after its link to severe skeletal birth defects triggered its withdrawal in 1957. However, years later it was deemed effective as a cancer treatment, even breeding the development and approval of even more successful derivatives, such as Celgene’s blockbuster Revlimid.
Meanwhile, Merck’s Vioxx — which was unceremoniously taken off shelves after its link to doubling patients’ risk of heart attack and stroke emerged — could resurface as a generic treatment for a side effect experienced by hemophilia patients. The generic version is being prepped for a pivotal trial slated to begin next year.
But akin to traditional drug development, drug repurposing has also seen its share of setbacks. Two examples of late-stage failures include the bid to use the antihistamine, latrepirdine, as a treatment for Huntington’s disease, as well as the pursuit of repurposing the antibiotic, ceftriaxone, as a medicine for ALS.
Healx’s Series B was led by European VC firm Atomico and joined by Global Brain and btov Partners. All previous investors, including Balderton Capital, Amadeus Capital Partners and Jonathan Milner, also participated in the round.
Healx did not initially plan to raise more money this year, but interest in their approach ballooned given their progress, Guilliams said. “I think that’s a really good sign for the investment landscape in the UK and Europe because for Europe it’s a pretty large B round…compared to the US.”
“And I’m wondering if part of that is let’s make sure we invest before Brexit kicks in.”