US regulators approve first human pill derived from fecal matter

US regulators have for the first time approved a pill derived from human faeces which a late-stage study showed can reduce recurrence of the potentially deadly gut infection C. difficile in adults.

The oral therapy named Vowst was developed by Seres, a Boston-based company backed by global food giant Nestlé and the US biotech incubator Flagship Pioneering behind vaccine maker Moderna.

It is one of a new class of so-called microbiome therapeutics, which aim to restore the balance of live bacteria in patients’ guts to boost their immune system and prevent infection.

C. difficile is a drug-resistant superbug associated with almost 30,000 deaths in the US every year and more than $4.8bn costs to the country’s healthcare system. One in six patients who has an infection will get another within eight weeks, a condition known as recurrent C. difficile, according to the Centers for Disease Control and Prevention.

Seres said approval of the first oral microbiota therapy by the US Food and Drug Administration would provide patients with new tool to fight C. difficile infections, which cause inflammation of the colon and diarrhoea.

The company said the approval validated the technology platform it is using to develop other microbiome therapies, including one aimed at preventing infection in patients undergoing stem cell transplants.

Eric Shaff, Seres chief executive, said the therapy marked the start of a new era for a microbiome sector that is attracting interest from investors, physicians and companies.

“This is a technology that’s here now. And I think for us it could be a tipping point for a whole new modality of treating patients,” he said.

C. difficile is a bacterial infection treated by antibiotics. But using these medicines can knock out a large portion of the microbes in the human microbiome that aid digestion and immune response, leaving people vulnerable to reinfection.

Faecal transplants using the stool of a healthy donor have become an increasingly common therapy over the past decade, although they are largely unregulated and have prompted safety alerts from the FDA on a handful of occasions.

These are typically administered via an enema, although a small number of healthcare centres do offer the therapy in tablet form on an investigation basis.

In November the FDA issued its first green light for a fecal transplant therapy when it approved Rebyota, a product developed by Swiss drug company Ferring that also targets C. difficile. The product is prepared using the stool of a qualified donor and administered rectally via a fecal transplant, in contrast to the pill developed by Seres.

Joseph Thome, analyst at Cowen, said the oral therapy developed by Seres would be more convenient to administer than Rebyota.

“Seres therapy could be really big — the consultants we talk to estimate about 150,000 C. difficile recurrent infections in 2023,” said Thome, adding Vowst could generate peak sales of $850mn per year in the US.

Vowst is made by treating human faeces with ethanol, a process which kills many of the viruses and bacteria that can cause infections. But it leaves behind spores produced by a type of bacteria called Firmicutes, which compete with C. difficile bacteria in the gut and makes it harder for them to multiply and release toxins that trigger diarrhoea and inflammation.

A late-stage trial showed Vowst reduced C. difficile recurrence, with 88 per cent of individuals free of a repeat infection at eight weeks, compared to 60 per cent in participants who received placebo.

Alexander Khoruts, professor of medicine at the University of Minnesota Medical School, said approval of the Seres pill might mark the beginning of a new class of therapeutics after a decade of hype about the potential of microbiome medicine.

But he said a lot of follow-up research is required to prove the pill works in a real-world setting and can match the effectiveness of alternatives.

Khoruts said: “It’s the world’s first FDA-approved poop pill. However, there may still be potential for non-profit, less expensive alternatives. Importantly, research still needs to be done to understand the performance of all microbiota-based products over the long-term.”

Nestlé Health Science, a unit of Nestlé specialising in food nutrition which owns a 6 per cent stake in Seres, has agreed to jointly market the new therapy in the US and Canada. Nestlé will make a milestone payment of $125mn to Seres following the FDA approval and the companies will split profits from the drug equally.