A Phase IIIb, Prospective, Multicenter, Randomized, Open-label Study to Determine the Safety and Efficacy of Two Different Dosing Regimens of Saizen® (Recombinant Human Growth Hormone (r-hGH), Using Cool.Click™ in Subjects With Childhood-onset Growth Hormone Deficiency During the Adolescent Transition Phase (CATS)

This is a phase IIIb, prospective, multicenter, randomised, open label study to determine the safety and efficacy of two different dose regimens of r-hGH with a dose escalation scheme. Screening assessments must be completed 30 days prior to SD1 (Study Day 1). Eligible subjects ages 13 to 25 years will be randomised in equal allocation in a 1:1 ratio to one of two treatment groups (30 subjects/group). Daily subcutaneous injections will be self-administered or received from a designated individual using cool.click™, the needle-free growth hormone (GH) delivery device. The study consists of three periods: screening (up to 30 days prior to Study Day 1), active treatment (up to 24 weeks), and follow-up (4 week safety evaluation after the last dose of study medication).

Each subject will be required to complete a daily treatment diary to assess dosing compliance, adverse events, and concomitant medications. Each subject will receive one treatment diary at SD1, weeks 8, 12, and 24. Subjects will be required to record daily diary entries that will capture dosing compliance, adverse events, and concomitant medications. Depending upon treatment allocation and subject tolerability, dose titration will be increased as follows:

• Group A: 0.005 mg/kg/day for 30 days then increasing, with the Investigator's approval, to 0.010 mg/kg/day from day 31 to week 24.
• Group B: 0.010 mg/kg/day for 14 days with the opportunity to dose escalate, with the Investigator's approval, on day 15 to 0.02 mg/kg/day and day 29 to 0.03 mg/kg/day.

Scheduled study visits include screening, baseline, and weeks 8, 12, and 24. Dosage adjustments will be based on subject tolerability and telephone assessments from study drug initiation through week 6. Trunk fat will be measured at SD1, weeks 12 and 24 (or early termination visit). Routine clinical laboratory assessments (hematology, blood chemistries, and urinalysis) will be performed pre-treatment (-30 to -1 SD1) and post-treatment on week 24 (or early termination visit). Special laboratory assessments include the central analysis of lipid panel, fasting insulin, fasting glucose, insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 3 (IGFBP-3), free thyroxine (T4) , total T4, C-reactive protein (CRP). Physical exams will be performed at screening, weeks 12 and 24. Safety evaluations will occur during scheduled study visits, through telephone assessments, and by the review of adverse events and concomitant events on the subject treatment diary.