Favorable results from global phase II study of Voxzogo for injection in infants and young children with achondroplasia are presented at The Endocrine Society annual meeting.

In the overall population of all randomized and sentinel subjects, the study showed an improvement in height Z-score (a measure of height adjusted for age and sex in reference to the average stature population and reported as a Standard Deviation, SD) as compared to placebo at 52 weeks. Voxzogo (n=43), compared to placebo (n=32), increased height Z-score by 0.30 SD (95% CI 0.07, 0.54) and annualized growth velocity (AGV) by 0.92cm/year (95% CI 0.24, 1.59). This improvement in height Z-score was consistent with improvements previously observed after one year of treatment in children over five years of age. In the randomized population (excluding sentinel subjects) and in the individual age subgroups, a trend toward increased height Z-score was observed. Voxzogo did not significantly impact upper-to-lower body segment ratio, which changed by -0.06 (95% CI -0.15, 0.03) over this 52-week period.

"These data are very encouraging and supportive of early treatment initiation – there is clearly the potential these younger children could see meaningful benefit from treatment with Voxzogo. Importantly this is just the beginning: we look forward to the results of future analyses addressing additional endpoints and await further data on longer term follow up in this population with complex needs," said Melita Irving, Clinical Geneticist at Guy's and St Thomas' NHS Foundation Trust, London, UK and investigator for the Voxzogo clinical program at the Evelina London Children's Hospital.

Voxzogo Safety: The safety profile was generally consistent with that seen in older subjects in the Phase III Voxzogo 301 study (the current label population). Serious Adverse Events (SAEs) were higher in the placebo group (18%) compared to Voxzogo-treated children (7%). All SAEs, including a fatal respiratory arrest (reported as a sudden infant death syndrome in a treated infant with pre-existing respiratory morbidity), were deemed by the investigators to be unrelated to treatment. The most common adverse events were mild and self-limiting injection site reactions.

BioMarin intends to meet with regulatory health authorities in the second half of 2022 to discuss next steps to expand access to Voxzogo for the treatment of achondroplasia in younger children.

Voxzogo is FDA indicated to increase linear growth in pediatric patients with achondroplasia who are 5 years of age and older with open epiphyses. This indication is approved under accelerated approval based on an improvement in annualized growth velocity.