Linear growth of children with X-linked hypophosphatemia treated with burosumab: a real-life observational study.

To assess the long-term efficacy of burosumab for pediatric patients with X-linked hypophosphatemia, focusing on linear growth. This multi-center retrospective study included 35 pediatric patients who began treatment with burosumab between January 2018 and January 2021. We collected clinical data, anthropometric measurements, laboratory results, and Rickets Severity Score (RSS), from 2 years prior to treatment initiation and up to 4 years after. Burosumab was initiated at a mean age of 7.5 ± 4.4 years (range 0.6-15.9), with a mean initial dose of 0.8 ± 0.3 mg/kg, which was subsequently increased to 1.1 ± 0.4 mg/kg. The patients were followed for 2.9 ± 1.4 years (range 1-4) after initiating burosumab. Serum phosphorus levels increased from 2.7 ± 0.8 mg/dl at burosumab initiation to 3.4 ± 0.6 mg/dl after 3 months and remained stable (p < 0.001). Total reabsorption of phosphorus increased from 82.0 ± 6.8 to 90.1 ± 5.3% after 12 months of treatment (p = 0.041). The RSS improved from 1.7 ± 1.0 at burosumab initiation to 0.5 ± 0.6 and 0.3 ± 0.6 after 12 and 24 months, respectively (p < 0.001). Both height z-score and weight z-score improved from burosumab initiation to the end of the study: from - 2.07 ± 1.05 to - 1.72 ± 1.04 (p < 0.001) and from - 0.51 ± 1.12 to - 0.11 ± 1.29 (p < 0.001), respectively. Eight children received growth hormone combined with burosumab treatment. Height z-score improved among those who received growth hormone (from - 2.33 ± 1.12 to - 1.94 ± 1.24, p = 0.042) and among those who did not (from - 2.01 ± 1.01 to - 1.66 ± 1.01, p = 0.001). CONCLUSION:  Burosumab treatment in a real-life setting improved phosphate homeostasis and rickets severity and enhanced linear growth. WHAT IS KNOWN: • Compared to conventional therapy, burosumab treatment has been shown to increase serum phosphate levels and reduce the severity of rickets. • The effect of burosumab on growth is still being study. WHAT IS NEW: • Height z-score improved between the start of burosumab treatment and the end of the study (-2.07 ± 1.05 vs. -1.72 ± 1.04, p < 0.001). • Eight children received burosumab combined with growth hormone treatment without side effects during the concomitant treatments.

A multicenter, randomized, double-blind, placebo-controlled, crossover trial to evaluate the efficacy and safety of zolmitriptan nasal spray for the acute treatment of migraine in patients aged 6 to 11 years, with an open-label extension.

OBJECTIVE: To evaluate the efficacy and safety of zolmitriptan nasal spray (ZNS) in the acute treatment of migraine headache in patients aged 6 to 11 years. BACKGROUND: Triptans have demonstrated efficacy in adults, but pediatric studies of these agents have largely failed and there are few triptan options for these patients. Because lack of response to 1 triptan does not necessarily preclude response to an alternate triptan, additional triptan options for pediatric patients are desirable. METHODS: This Phase 3, randomized, double-blind, placebo-controlled, multicenter crossover trial with an open-label extension enrolled patients aged 6 to 11 years with a diagnosis of migraine for ≥6 months and ≥16 headache-free days/month (N = 373). After a run-in period to eliminate placebo responders, 186 patients were randomized within their body weight stratum to ZNS followed by matching placebo, or placebo followed by matching ZNS. Patients <50 kg who were randomly allocated to ZNS were randomized to 5:1 to ZNS 2.5 or 1.0 mg; those ≥50 kg were randomized 5:1 to ZNS 5.0 or 2.5 mg. Patients had 6 weeks to treat 1 moderate to severe migraine headache and then crossed over to the alternate arm, during which they had 6 weeks to treat a second migraine attack. Patients could participate in a subsequent 6-month outpatient open-label extension. The primary efficacy endpoint was pain-free status at 2 h in patients treated with the high dose from each stratum. RESULTS: The trial was terminated early due to slow enrollment. Three hundred patients (mean age, 9 years) entered the placebo run-in period and 186 entered the double-blind period. Pain-free status at 2 h postdose was achieved by 45/133 (33.8%) and 30/128 (23.4%) of patients who received high-dose ZNS and placebo, respectively (p = 0.0777; odds ratio [OR] 1.51; 95% confidence interval [CI] 0.96, 2.38). Several secondary endpoints achieved statistical significance. There were few treatment-related adverse events and none led to discontinuation. ZNS retained efficacy and demonstrated a consistent safety profile throughout the 6-month open-label extension. CONCLUSION: The effect of high-dose ZNS on the primary endpoint of pain-free status at 2 h did not achieve statistical significance. ZNS was safe and well tolerated in this pediatric population.