ESPE Abstracts

Background: CPP is commonly treated with triptorelin, a gonadotropin-releasing hormone (GnRH) analogue. It is available as 1-month and 3-month prolonged-release (PR) formulations, but only the former is approved for CPP in China. Overseas studies have proved the efficacy and safety of triptorelin 3-month PR formulation; this study evaluated efficacy and safety in Chinese children with CPP.

Methods: In this 12-month, open-label, multicentre, single-arm study (NCT04736602), Chinese children with CPP received four doses of triptorelin pamoate 15 mg (Diphereline®, Ipsen; delivering 11.25 mg of triptorelin) on Day 1 and Months 3, 6 and 9. Primary endpoint was the proportion of participants with luteinising hormone (LH) suppression (stimulated peak LH ≤3 IU/L after GnRH stimulation) at Month 3. Secondary endpoints included changes from baseline in hormone levels, pubertal stage, auxological parameters, difference between bone and chronological age, uterine length (girls) or testicular volume (boys), and treatment-emergent adverse events (TEAEs).

Results: Overall, 32 patients were enrolled (90.6% female; mean age 7.6 [SD, 0.8] years), of which 31, 30 and 29 completed Month 3, 6 and 12 assessments, respectively. At Month 3, 100% had LH suppression to ≤3 IU/L after GnRH stimulation; this was maintained in 93.5% at Months 6 and 12. Mean basal and peak LH and follicle-stimulating hormone levels were substantially suppressed throughout follow-up in females and males. Sex hormone suppression to prepubertal values (girls, oestradiol ≤20 pg/mL; boys, testosterone ≤0.3 ng/mL) was demonstrated in 100%, 96.8% and 93.5% at Months 3, 6 and 12, respectively. 92.9% and 89.3% of girls had stable breast development at Months 6 and 12, respectively; all boys had stable genital development until Month 12. Mean growth velocity was 8.07, 5.24 and 6.94 cm/year at Months 3, 6 and 12, respectively, and mean difference between bone and chronological age fell from 2.85 years at baseline to 2.39 years at Month 12. In girls, uterine length was stable or reduced at Months 6 and 12 versus baseline, while testicular volume decreased in boys. Eighteen drug-related TEAEs were reported in 10 patients (34.5%), and 2 (6.3%) had serious TEAEs (both pneumonia; unrelated to study treatment). No TEAEs led to treatment discontinuation, and there were no deaths.

Conclusions: Treatment with triptorelin 3-month PR formulation for 12 months demonstrated similar efficacy and favourable safety in Chinese children with CPP compared with previous studies elsewhere. Findings support triptorelin 3-month PR as a viable option for this population.