BioCryst Pharmaceuticals has enrolled the first participant in the pivotal APeX-P trial of Orladeyo (berotralstat) in paediatric hereditary angioedema (HAE) patients.

The open-label APeX-P trial has been designed for assessing Orladeyo’s safety and pharmacokinetics (PK) in paediatric HAE patients aged two to less than 12 years old.

It will include an initial standard-of-care (SOC) treatment period of 12 weeks, a subsequent open-label ORLADEYO treatment period that will last 48 weeks, plus treatment continuation for up to 144 weeks.

The trial will enrol the participants into four dose cohorts, based on their body weight.

Initially, higher weight cohorts (Cohorts 1 and 2) will enrol first.

The company stated that the safety evaluations and PK modelling from all the available PK data will be used for confirming the weight bands to enrol participants in Cohorts 3 and 4.

Descriptive statistical methods will be used for summarising Orladeyo’s effectiveness in the APeX-P trial.

The characterisation of the PK profile of Orladeyo in paediatric patients is the study’s primary endpoint.

BioCryst chief medical officer Dr Ryan Arnold said: “Today’s announcement marks a very important step in our continuing efforts to reduce the burden of therapy for people living with HAE around the world with oral, once-daily Orladeyo.

“Paediatric patients are a particularly important group where the challenges posed by disease and treatment can be significant to these children and their families, especially given the uncertainty they face as they are newly diagnosed during childhood.

“It is imperative that we strive to help normalise patients’ lives, as early experiences can have a lasting impact on how HAE is perceived, and managed, for their entire lifetimes.”

The company intends to submit a supplemental New Drug Application (sNDA) to use Orladeyo for prophylaxis to prevent HAE attacks in paediatric patients, after completion of the APeX-P trial.