This study aims to evaluate the efficacy and safety of GB08 injection compared to Norditropin NordiFlex in pediatric patients with growth hormone deficiency (PGHD). It seeks to resolve the following questions:
* 1: Does GB08 injection demonstrate comparable efficacy in treating PGHD at 24 weeks compared to Norditropin NordiFlex? * 2: Which dose (0.4 mg/kg, 0.8 mg/kg, and 1.2 mg/kg) of GB08 injection best balances efficacy and safety in treating PGHD at 24 weeks? * 3: Does GB08 injection maintain its efficacy in treating PGHD at 52 weeks compared to Norditropin NordiFlex? To achieve these, GB08 injection will be compared to Norditropin NordiFlex to see if it provides a more effective or safer treatment option for PGHD.
This is a Phase II/III, Seamless, Multicenter, Randomized, Open-Label, Positive-Comparator Controlled Clinical Trial with two stages. Stage 1 answers questions #1 and #2 by comparing the efficacy and safety of GB08 injection and Norditropin NordiFlex intervention among PGHD at 24 weeks. It involves four groups (n=16 each): GB08 0.4 mg/kg, GB08 0.8 mg/kg, GB08 1.2 mg/kg, and Norditropin NordiFlex 0.035 mg/kg. GB08 and Norditropin NordiFlex will be administered once weekly and once daily, respectively. The primary outcome measurement is annualized height velocity (AHV) at 24 weeks. Other measurements include growth hormone levels, safety parameters, immunogenicity markers, and pharmacokinetic/pharmacodynamic profiles.
The optimal GB08 dose will be further investigated in Stage 2, which answers question #3. At this stage, PGHD patients will randomly receive either GB08 injection or Norditropin NordiFlex intervention for 52 weeks (n=102 for each). After that, the efficacy and safety of GB08 will also be detected.
Absolute height 2 standard deviations (SD) below the mean height of children of the same age and sex, according to the standardized growth curves for children and adolescents in China (0-18 years old) published in 2009.
Annualized height velocity (AHV) ≤ 5.0 cm/year, calculated from measurement of 6 to 18 months before screening.
GH peak ≤ 10 ng/ml proved by two different GH stimulation tests within a year before screening.
Bone age lagging at least 1 year behind actual age (bone age assessment within the past 6 months before screening), with girls < 10 years old and boys < 11 years old.
History of systematic growth-promoting therapy, including growth hormone and sex hormones.
Severe allergic constitution or known allergy to growth hormone or its excipients, such as mannitol, lysine, or sodium chloride.
Closed epiphyses.
Other types of growth disorders such as idiopathic short stature, Turner syndrome, Noonan syndrome, Prader-Willi syndrome, and Russell-Silver syndrome.
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Treatment groupsSee each treatment group below.