NCT07221851|RecruitingPhase 3FDA DrugFDA Device

Trial Investigating the Efficacy and Safety of Weekly Lonapegsomatropin Compared to Daily Somatropin in Children and Adolescents With Short Stature or Growth Failure Due to Growth Hormone Sufficient Disorders

A Pivotal, Parallel-Arm, Phase 3, Open-Label, Active-controlled, Global, Multicenter, Randomized Basket Trial Investigating the Efficacy and Safety of Once-weekly Lonapegsomatropin Compared to Daily Somatropin in Prepubertal Children and Adolescents With Growth Failure or Short Stature Due to Growth Hormone Sufficient Disorders - Turner Syndrome, SHOX Deficiency, Small for Gestational Age, and Idiopathic Short Stature

Ascendis Pharma A/S ClinicalTrials.gov

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1 other identifier

ASND0047

Study Type

interventional

Target

186

Locations

2 countries

Sites

Timeline

RegisteredOct 2025

StartedDec 2025

CompletionMar 2029

Brief Summary

This basket trial will enroll prepubertal children and adolescents with clinically diagnosed and genetically confirmed (if applicable) TS, SHOX-D, SGA, or ISS between ages of ≥2 and \<18 years with open growth plates. The purpose of the study is to see how well treatment with once-weekly lonapegsomatropin works compared to treatment with daily somatropin. Approximately 186 participants will be distributed equally (1:1), to receive either lonapegsomatropin for 2 years or somatropin for 1 year followed by lonapegsomatropin for 1 year. This trial will be conducted in the United States, France, Germany, Italy, Romania, Spain and South Korea.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

186

participants targeted

Target at P25-P50 for phase_3

Timeline

34mo left

Started Dec 2025

Typical duration for phase_3

Geographic Reach

2 countries

11 active sites

Status

recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

3.2 years study duration

Study Progress12%

Dec 2025Mar 2029

First Submitted

Initial submission to the registry

October 14, 2025

Completed

14 days until next milestone

First Posted

Study publicly available on registry

October 28, 2025

Completed

2 months until next milestone

Study Start

First participant enrolled

December 12, 2025

Completed

2.1 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 1, 2028

Expected

1.1 years until next milestone

Study Completion

Last participant's last visit for all outcomes

March 1, 2029

Last Updated

April 21, 2026

Status Verified

April 1, 2026

Enrollment Period

2.1 years

First QC Date

October 14, 2025

Last Update Submit

April 20, 2026

Conditions

Short Stature Homeobox Gene Mutation Idiopathic Short Stature Turner Syndrome Small for Gestational Age at Delivery

Keywords

Turner SyndromeNoonan SyndromeGrowth HormoneShort StatureGrowth FailureSex Chromosome DisordersChromosome DisordersEndocrine System DiseasesPituitary Hormones, AnteriorPituitary HormonesHormonesHormone SubstitutesHuman Growth HormoneLonapegsomatropinSex Chromosome Disorders of Sex DevelopmentImpaired GrowthsomatropinGrowth Hormone SufficiencyShort Stature Homeobox Gene MutationShort Stature Children Born Small for Gestational AgeIdiopathic Short Stature

Outcome Measures

Primary Outcomes (1)

Annualized Height Velocity (AHV) (cm/year)
To evaluate the efficacy of lonapegsomatropin as compared to somatropin in children and adolescents with TS, SHOX-D, SGA, or ISS
52 Weeks

Secondary Outcomes (5)

Annualized Height Velocity (AHV) (cm/year)
104 Weeks
Change from baseline in height standard deviation score (SDS)
52 Weeks and 104 Weeks
Change from baseline in Bone Age (years)
52 Weeks and 104 Weeks
Change from baseline in ratio of Bone Age/chronological age
52 Weeks and 104 Weeks
Number of participants with treatment-related adverse events (AEs)
52 Weeks and 104 Weeks

Study Arms (2)

Lonapegsomatropin, once daily

EXPERIMENTAL

Participants will receive Lonapegsomatropin by subcutaneous injection for 2 years (104 weeks)

Combination Product: Lonapegsomatropin [SKYTROFA®]

somatropin, once daily

ACTIVE COMPARATOR

Participants will receive somatropin by subcutaneous injection for 1 year (52 weeks) followed by lonapegsomatropin for 1 year (52 weeks)

Combination Product: Somatropin Pen Injector

Interventions

Lonapegsomatropin [SKYTROFA®]COMBINATION_PRODUCT

Subcutaneous injection once weekly

Lonapegsomatropin, once daily

Somatropin Pen InjectorCOMBINATION_PRODUCT

Subcutaneous injection once daily

somatropin, once daily

Eligibility Criteria

Age2 Years - 17 Years

Sexall

Healthy VolunteersNo

Age GroupsChild (0-17)

You may qualify if:

Chronological age between ≥2 and \<18 years, at start of screening.
Naïve to growth hormone and growth hormone promoting therapies.
Prepubertal.
Able to stand without assistance.
Diagnosis of TS, SHOX-D, SGA, or ISS with impaired growth or short stature, according to the following disease-specific criteria:
TS or SHOX-D (Léri-Weill dyschondrosteosis):
Diagnosis confirmed by a genetic test. NOTE: Historical test results are acceptable for proof of diagnosis. For karyotypes, a minimum of 20 cells must be counted.
Impaired growth or short stature defined as:
(i.) AHV \<25th percentile over a time span of 6-16 months prior to screening utilizing a historical height properly documented in a health care setting (self-measurement record is not accepted) OR (ii.) Height \<5th percentile for sex and age according to the Centers for Disease Control Growth Charts for the United States
SGA without catch-up growth:
c. Birth weight and/or birth length \< -2.0 SDS for gestational age according to the 2006 World Health Organization Child Growth Standards. For infants born premature, the Fenton Preterm Infant Growth Chart (Fenton 2013) should be used.
d. Impaired growth or short stature defined as: (i.) AHV \<25th percentile over a time span of 6-16 months prior to screening properly documented in a health care setting (self-measurement record is not accepted) OR (ii.) Height \< -2.0 SDS for age and sex according to the 2000 Centers for Disease Control Growth Charts for the United States for children ≥ 3 years or height \< -2.5 SDS for age and sex according to the for children ≥ 2 years and \< 3 years
ISS:
e. Height \< -2.25 SDS for sex and age according to the Centers for Disease Control Growth Charts for the United States with no identifiable cause for short stature.
f. Documented normal GH-IGF-1 axis, defined as either: (i.)IGF-1 SDS \>0 at screening based on central laboratory OR (ii.)Historical documentation of normal peak GH upon stimulation test (as defined by local institution) g. 46,XX chromosome as determined by karyotype or microarray if female. For karyotypes, a minimum of 30 cells must be counted.
+2 more criteria

You may not qualify if:

Advanced bone age X-ray by central reading defined as \>20% above chronological age in months (Greulich 1959).
Closed epiphyses as defined as bone age of ≥14.0 years in females or ≥16.0 years in males.
Current clinical diagnosis of diabetic retinopathy
Any diagnosis or presence at screening of the following:
Untreated moderate or severe sleep apnea as determined by formal (local) read of an inpatient or at-home sleep study.
Prader Willi syndrome with severe obesity, history of severe upper airway obstruction, or severe respiratory impairment.
Signs/symptoms of intracranial hypertension, active proliferative retinopathy.
Uncontrolled hypo- or hyperthyroidism.
Uncontrolled diabetes mellitus (defined as: HbA1c \>7.5% from central laboratory at screening).
Known history or diagnosis of any gastrointestinal inflammatory condition, HIV, radiation exposure, other skeletal dysplasias, growth hormone deficiency, and/or cardio-thoracic surgery due to their independent effects on growth.
Any significant hepatic or renal abnormality, such as abnormal renal function (defined as eGFR \<60 mL/min/1.73m2).
Undiagnosed or uncontrolled hypertension.
Receiving treatment with any agent that might influence growth or interfere with GH secretion or action including any sex steroids and stimulants for attention-deficit/hyperactivity disorder (ADHD).
High dose inhaled glucocorticoid for more than 28 consecutive days total over the course of 12 months.
Female who is pregnant, plans to be pregnant, or breastfeeding.
+8 more criteria

Contact the study team to confirm eligibility.