Healx, a Cambridge-based startup cofounded by one of the inventors of Viagra, has raised $56m to expand the rollout of its artificial intelligence technology that hunts for new treatments for rare diseases. 

The startup’s approach has been shaped by cofounder Dr David Brown’s experience in discovering Viagra.

When Viagra was first developed the hope was that it would be able to treat heart problems. But it was the side effects of the drug that ended up being its selling point.

Healx‘s focus is on using AI to make predictions about how diseases might respond to drugs that already exist.

“Viagra is a classic example of highly successful repurposing of a safe drug. This is the approach we are now scaling at Healx, repurposing approved drugs (and unique combinations of them) and matching them to rare diseases,” said Dr David Brown.

While existing drugs are often already patented, Healx says that it is possible to cash in on the discovery of a new use-case for a drug using various other types of patent, such as “method-of use” patents.

Healx’s $56m Series B marks another big investment into the AI healthcare space, which is attracting large quantities of capital and has generated some big-name startups like DeepMind and Babylon. According to the latest figures from technology investment company Atomico, healthtech is the third most dominant industry in European tech, with around $2.6bn invested in 2018, up from $1.6bn in 2017.

Healx cofounder Tim Guilliams says that most companies in the market focus on a software-first business model, but what makes Healx unique is its focus on finding treatments. 

“I think there will be a graveyard of machine learning companies who sell software to big pharma. At Healx we have kept our heads down and focussed on using the tech to identify treatments,” he said. 

The company will use the fresh funds to launch its “rare treatment accelerator”, which is a new programme to bring Healx together in collaboration with rare disease patient groups and clinicians. 

The round was led by Atomico and included investment from venture capital firms Global Brain and btov Partners. Previous investors Balderton Capital and Amadeus Capital Partners also participated in the round.