Savarirayan Ravi, De Bergua Josep Maria, Arundel Paul, Salles Jean Pierre, Saraff Vrinda, Delgado Borja, Leiva-Gea Antonio, McDevitt Helen, Nicolino Marc, Rossi Massimiliano, Salcedo Maria, Cormier-Daire Valerie, Skae Mars, Kannu Peter, Phillips John, Saal Howard, Harmatz Paul, Candler Toby, Hill Dawn, Muslimova Elena, Weng Richard, Bai Yun, Raj Supriya, Hoover-Fong Julie, Irving Melita, Rogoff Daniela
Murdoch Children's Research Institute, Melbourne, VIC, Australia.
Hospital Vithas Vitoria, Vitoria-Gasteiz, Spain.
N Engl J Med. 2025 Feb 27;392(9):865-874. doi: 10.1056/NEJMoa2411790. Epub 2024 Nov 18.
Achondroplasia is a genetic skeletal condition that results in disproportionately short stature and medical complications throughout life. Infigratinib is an orally bioavailable FGFR1-3 selective tyrosine kinase inhibitor in development for achondroplasia.
In this phase 2 dose-finding study, we evaluated the safety and efficacy of oral infigratinib in children with achondroplasia between the ages of 3 and 11 years. A total of 72 children were enrolled in five sequential cohorts to receive daily infigratinib at doses of 0.016 mg per kilogram of body weight (cohort 1), 0.032 mg per kilogram (cohort 2), 0.064 mg per kilogram (cohort 3), 0.128 mg per kilogram (cohort 4), and 0.25 mg per kilogram (cohort 5) for 6 months, followed by 12 months of extended treatment in which the dose in cohorts 1 and 2 could be escalated to the next ascending level at months 6 and 12. The primary safety outcome was the incidence of adverse events that led to a decrease in the dose or discontinuation of infigratinib. The primary efficacy outcome was the change from baseline in the annualized height velocity.
During treatment, all the children had at least one adverse event, most of which were mild or moderate in severity; none resulted in treatment discontinuation. In cohort 5, an increased annualized height velocity was observed, which persisted throughout the duration of the study, with a mean change from baseline at 18 months of 2.50 cm per year (95% confidence interval [CI], 1.22 to 3.79; P = 0.001). The mean change from baseline in height z score was 0.54 (95% CI, 0.35 to 0.72) relative to an untreated achondroplasia reference population at 18 months; the mean change from baseline in the upper-to-lower body segment ratio was -0.12 (95% CI, -0.18 to -0.06).
The administration of oral infigratinib did not result in any apparent major safety signal and increased the annualized height velocity and z score and decreased the upper-to-lower body segment ratio at 18 months of treatment in cohort 5. (Funded by BridgeBio Pharma; PROPEL2 ClinicalTrials.gov number, NCT04265651.).
软骨发育不全是一种遗传性骨骼疾病，会导致身材比例严重矮小，并伴随终生的医学并发症。英菲格拉替尼是一种口服生物利用度良好的FGFR1-3选择性酪氨酸激酶抑制剂，正在研发用于治疗软骨发育不全。
在这项2期剂量探索研究中，我们评估了口服英菲格拉替尼对3至11岁软骨发育不全儿童的安全性和疗效。共有72名儿童被纳入五个连续队列，分别接受每日剂量为每公斤体重0.016毫克（队列1）、0.032毫克每公斤（队列2）、0.064毫克每公斤（队列3）、0.128毫克每公斤（队列4）和0.25毫克每公斤（队列5）的英菲格拉替尼治疗6个月，随后进行12个月的延长治疗，其中队列1和队列2的剂量可在第6个月和第12个月提升至下一个递增水平。主要安全结局是导致英菲格拉替尼剂量减少或停药的不良事件发生率。主要疗效结局是年化身高增长速度相对于基线的变化。
在治疗期间，所有儿童至少发生了一次不良事件，大多数不良事件的严重程度为轻度或中度；无一例导致治疗中断。在队列5中，观察到年化身高增长速度增加，且在整个研究期间持续存在，在18个月时相对于基线的平均变化为每年2.50厘米（95%置信区间[CI]，1.22至3.79；P = 0.001）。相对于未治疗的软骨发育不全参考人群，在18个月时身高z评分相对于基线的平均变化为0.54（95%CI，0.35至0.72）；上身与下身节段比相对于基线的平均变化为-0.12（95%CI，-0.18至-0.06）。
口服英菲格拉替尼未产生任何明显的主要安全信号，且在队列5中，治疗18个月时年化身高增长速度增加、z评分升高，上身与下身节段比降低。（由BridgeBio Pharma资助；PROPEL2临床试验注册号，NCT04265651。）
