Sildenafil, a drug developed by Pfizer to treat angina, was failing to show significant benefit in early clinical trials – but soon revealed itself to be effective at serving a very different purpose.
Researchers found that some trial participants taking the drug were experiencing more erections than usual, and, after being approved in 1998 for erectile dysfunction, sildenafil took the world by storm under the brand name Viagra.
For Viagra’s co-inventor David Brown, that was just the beginning of a mission to repurpose existing drugs for areas of unmet need.
UK-based Healx, co-founded by Brown and Tim Guilliams in 2014, is dedicated to ensuring no drug’s potential is overlooked. The company leverages artificial intelligence (AI) technology to identify promising drugs and compounds already approved or in clinical development that could be repurposed to treat rare diseases.
The rare disease space is one crying out for innovation; while there are as many as 7,000 rare diseases, only 5% of these currently have a form of treatment. The nature of rare diseases – that each one affects only a small number of people worldwide – means that pharmaceutical companies are reluctant to invest the time and money required to discover and develop new drugs for them.
Rare Treatment Accelerator
To circumvent the obstacles associated with developing novel therapies for rare diseases, Healx focuses on what it calls the “redevelopment” of existing drug candidates.
Through its Rare Treatment Accelerator, the company partners with academic, patient and industry groups to advance the redevelopment of drugs that are intended or approved for another indication but have shown promise for rare disease treatment, modifying them to deliver benefit in one or more diseases.
These modification strategies can include “changing the route of administration so it can hit a different tissue or organ, modifying the molecular structure so that more of the drug can reach the desired target, and combining two or more drugs in order to reduce the dosages and side effects of each while creating synergistic therapeutic effects”.
To accelerate promising drug candidates towards approval and into the hands of rare disease patients, Healx provides in-house expertise, funding for clinical trials and approval, and the company’s advanced technology.
AI-powered drug discovery
Healx’s AI drug discovery platform, HealNet, uses machine learning methods to extract disease knowledge from a variety of published sources and predict which drugs and combination therapies are most likely to succeed in the clinic.
Healx describes its approach to drug discovery as “hypothesis-free”. Its technology is widely regarded as the most efficient and comprehensive AI platform for rare diseases in the world and enables the company to conduct automated, large-scale drug discovery that drastically reduces time and cost – and can uncover candidates that may not have been considered using specific targets.
Pipeline and partnerships
Healx has entered a number of collaborative partnerships with academic, patient and industry groups since its inception, aimed at discovering new treatments for a range of rare conditions such as Friedreich’s ataxia, muscular dystrophy and polycystic kidney disease.
The company currently has 18 therapy candidates in its pipeline, including a potential Covid-19 treatment that has entered the preclinical validation stage.
Healx’s most advanced project so far is with the US patient group FRAXA Research Foundation. The two joined forces in 2016, and their drug candidate for fragile X syndrome – a genetic condition that causes a range of developmental problems – is set to enter Phase I/IIa clinical trials later this year.