Treatment Experience of Children with Growth Hormone Deficiency in the Phase 3 fliGHt Trial: Switching from Daily Growth Hormone to Once-weekly TransCon hGH

Abstract

Background: Patients treated with daily growth hormone (hGH; somatropin) therapy have long requested the option of a treatment requiring fewer injections. Once-weekly TransCon hGH is an investigational long-acting prodrug in development for the treatment of growth hormone deficiency (GHD) designed to fulfill this unmet need. TransCon hGH consists of 3 components: unmodified hGH, an inert carrier that protects it, and a linker that temporarily binds the two. Aims: To evaluate preference and treatment burden of patients and parents/caregivers in the Phase 3 fliGHt Trial of children with GHD treated with once-weekly TransCon hGH who switched from daily growth hormone therapy. Methods: All subjects initiated open-label once-weekly TransCon hGH 0.24 mg hGH/kg/week (via vial and syringe) irrespective of prior daily hGH dose. Subjects 3 to 17 years old must have been treated previously with daily hGH for 13 to 130 weeks; subjects 6 months to 3 years old may have been treatment-naïve or treated with daily hGH for ≤130 weeks. To assess preference and treatment burden, subjects ≥9 years old (C) and all parents/caregivers (P) completed the Preference Questionnaire (PQ-C/P) at Weeks 6 and 13, and Child Sheehan Disability Scale (CSDS-C/P) at baseline, Weeks 6, 13, and 26. Results: The most common daily hGH treatments that subjects used previously were Norditropin FlexPro (31%), Nutropin AQ Nuspin (19%), HumatroPen (17%), and Omnitrope Pen (17%). The majority of subjects and parents/caregivers preferred TransCon hGH over their previous daily hGH treatment, and this preference increased with continued use (74.0% and 87.7% at Week 6 and 83.8% and 90.1% at Week 13, respectively); the most important reason for this preference in both groups was the reduced frequency of injections. Treatment burden, as assessed by the CSDS-C/P, decreased from baseline to Week 26 (C:2.5 to 1.4 and P:5.7 to 1.9) with weekly TransCon hGH treatment. Conclusions: In the fliGHt Trial, once-weekly TransCon hGH was the preferred treatment option for children with GHD and reduced the treatment burden for both children and parents/caregivers relative to prior daily hGH treatments.