Applied Therapeutics slumps as FDA seeks more data on lead drug

Shares in Applied Therapeutics slumped today after it said it would have to delay a US filing for its lead drug programme AT-007, following an FDA request for more data.

The New York-based biopharma company had been hoping to file AT007 in its lead indication galactosaemia in the third quarter of last year, but said it will now have to wait for results from an ongoing phase 3 trial.

That won’t start to read out until the first quarter of 2022, but if that data isn’t strong enough to support a filing it will have to wait for at least another six months until the next scheduled analysis.

Galactosaemia is an inherited metabolic disorder caused by a defect in the ability to process galactose, a sugar found in milk, causing harmful metabolites to build up in the body. It can lead to vomiting and diarrhoea, jaundice, liver problems, and neurological problems.

At the moment, the rare disease can only be managed by restricting galactose from the diet, which can be challenging as many food products contain milk-based ingredients. Moreover, some galactose is also produced by the body itself.

There are no approved drugs to treat the disorder, which  affects approximately 3,000 patients with galactosaemia in the US and 80 new births each year, according to Applied Therapeutics.

AT-007 is an aldose reductase inhibitor (ARI) designed to replace the enzyme that is deficient in people with the disorder, restoring their ability to metabolise galactose.

Applied Therapeutics has previously said it hoped to be able to file for accelerated FDA approval based on biomarker data showing that AT-007 was able to reduce levels of galactitol, the main toxic metabolite in galactosaemia.

Now, it says the FDA has indicated it will need to see clinical outcomes data, such as cognition, speech, behaviour and motor skills, from the ongoing ACTION-Galactosemia Kids trial involving children aged two to 17 with the disorder in the marketing application.

Applied Therapeutics has already been asked by the FDA to modify the design of the open-label study in order to ensure continued access to treatment for the subjects as they moved from an initial biomarker assessment to the outcomes stage of the trial.

Chief executive and founder, Shoshana Shendelman, said she was “disappointed by this change in direction by the FDA” but insisted that the company remains “committed to bringing this important treatment to patients with galactosaemia.”

Applied Therapeutics will “continue to work with the FDA to determine the most expeditious path forward to regulatory approval and will provide an update on timing and plans accordingly,” she added.

It is also developing AT-007 for other rare disorders including sorbitol dehydrogenase deficiency (SORD) and phosphomannomutase 2 deficiency – a congenital disorder of glycosylation (PMM2-CDG). Another ARI – called AT-001 – is in a phase 3 trial as a treatment for diabetic cardiomyopathy.

Shares in the company were down around a third at the time of writing.

Photo by Kelly Sikkema on Unsplash

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