The US Food and Drug Administration (FDA) has granted ConSynance Therapeutics a rare paediatric disease designation for its oral therapy for the treatment of Prader-Willi syndrome.
As per the designation, the US-based company will be eligible to receive a priority review voucher if the drug candidate, named CSTI-500, is approved by the FDA.
Recipients can redeem priority review vouchers themselves for any chosen drug or can instead sell them to other pharma companies. Cutting four months off FDA review time and helping thrust an asset to market faster, vouchers are hot properties on the secondary market. They have commanded prices as high as $350m, though currently sell on average for around $100m.
Indicated for the treatment of Prader-Willi syndrome in children and adolescents, CSTI-500 is a triple monoamine reuptake inhibitor (TRI) that targets the neuropsychiatric behaviours seen in patients with the syndrome such as the desire for excessive eating and temper outbursts. ConSynance stated it is planning for a Phase II study, which will start next year.
CSTI-500 restores the balance of serotonin, dopamine and norepinephrine associated with these behaviours. The company states CSTI-500 is the first therapy in the space to address these symptoms of the syndrome, according to a 24 July press release.
Currently, human growth hormones are recommended for children with Prader-Willi syndrome. These can help improve muscle size and strength, increase energy levels, and aid in the change of facial appearance. Along with behavioural challenges and impaired muscle development, children with the syndrome also have learning difficulties, restricted growth, and a lack of sexual development.
The National Organization for Rare Disease (NORD) estimates that the incidence of the syndrome is between one in 10,000 – 30,000 individuals in the general population.
Position emission tomography (PET) has revealed CSTI-500’s brain target engagement in healthy volunteers. CSTI-500 has been studied in nearly 100 humans across three Phase I clinical trials. Two of these were single ascending dose and multiple ascending dose studies in healthy volunteers, with a third (NCT05504395) involving ten patients with Prader-Willi syndrome. There were no reported severe adverse events with the drug showing a similar efficacy profile in all three trials.
ConSynance CEO Shuang Liu said: “CSTI-500 stands out as the first drug candidate for Prader-Willi syndrome designed to address both hyperphagia and severe temper outbursts, providing a potential breakthrough and comprehensive treatment solution for this challenging disorder.”
