Long-term safety and effectiveness of a somatropin biosimilar (Omnitrope) in children requiring growth hormone therapy: analysis of final data of Italian patients enrolled in the PATRO children study.

Purpose: Omnitrope (a somatropin biosimilar), used to treat growth disturbances, is considered to have a good safety profile in children. Here, we present the analysis of final data of the Italian cohort of the PAtients TReated with Omnitrope (PATRO) Children study.

Methods: This multicenter, open-label, longitudinal, post-marketing surveillance study enrolled eligible children during 2010-2018. The primary objective was to assess the long-term safety of Omnitrope by recording all adverse events (AEs), serious AEs, and adverse drug reactions (ADRs). A secondary objective was to evaluate the long-term effectiveness of Omnitrope using height measurements.

Results: A total of 375 patients were included in the Italian cohort of the PATRO Children study. After a mean ± standard deviation (SD) follow-up duration of 40.9 ± 24.6 months, 607 AEs were reported in 58.4% of patients, mostly of mild (52.5%) or moderate (15.7%) severity. The most common AEs were headache (11.7%), elevated insulin-like growth factor (IGF)-1 (4.8%), abdominal pain (4.3%), and pyrexia (3.7%). Sixty-seven ADRs occurred in 52 patients (13.9%); the most common ADRs were elevated IGF-1 (3.5%) and insulin resistance (2.9%). Mean ± SD height standard deviation scores in treatment-naïve patients increased from -2.5 ± 0.7 at baseline (n = 318) to -1.3 ± 0.7 at 5 years (n = 56) and to -0.8 ± 0.7 at 7.5 years (n = 13).

Conclusions: This final analysis extends the interim analysis findings from the PATRO Children study and confirms the long-term safety and effectiveness of Omnitrope in Italian pediatric patients with growth disturbances.