Study of the Efficacy and Safety of Somatropin in Japanese Participants With PWS

NCT04697381 | Completed Phase 3 Results

• 3 other identifiers: A62813232024-000101-32NCT04697381
• Study Type: interventional
• Target: 33
• Locations: 1 country
• Sites: 5

Brief Summary

This is a multicenter, open label, multi cohort study to evaluate the efficacy and safety of somatropin in a cohort of Japanese participants with PWS.

Conditions

Prader-Willi Syndrome

Outcome Measures

Primary Outcomes (2)

• Change From Baseline to Month 12 in Lean Body Mass Measured by Dual-Energy X-ray Absorptiometry (DEXA): Adult Cohort

  Lean body mass, a measurement of body composition, was assessed by DEXA scan, and calculated as lean body mass (%) = lean body mass kilogram (kg) / (lean body mass \[kg\] + fat mass \[kg\]) \*100.

  Baseline, Month 12

• Change From Baseline to Month 12 in Lean Body Mass Measured by DEXA: GH Naive Pediatric and GH Treated Pediatric Cohort

  Lean body mass, a measurement of body composition, was assessed by DEXA scan, and calculated as lean body mass (%) = lean body mass (kg) / (lean body mass \[kg\] + fat mass \[kg\])\*100.

  Baseline, Month 12

Secondary Outcomes (9)

• Change From Baseline to Month 12 in Lean Body Mass Measured by Bioelectrical Impedance Analysis (BIA)-Adult Cohort

  Baseline, Month 12

• Change From Baseline to Month 12 in Lean Body Mass Measured by BIA-GH Naive Pediatric and GH Treated Pediatric Cohort

  Baseline, Month 12

• Change From Baseline to Month 12 in Body Fat (Percentage) Measured by DEXA: Adult Cohort

  Baseline, Month 12

• Change From Baseline to Month 12 in Body Fat (Percentage) Measured by DEXA: GH Naive Pediatric and GH Treated Pediatric Cohort

  Baseline, Month 12

• Change From Baseline to Month 12 in Adipose Tissue Distribution Measured by Abdominal Computed Tomography (CT)

  Baseline, Month 12

Study Arms (3)

somatropin - GH naïve pediatric cohort

EXPERIMENTAL

All participants will receive somatropin.

Biological: somatropin - GH naïve pediatric cohort

somatropin - GH treated pediatric cohort

EXPERIMENTAL

All participants will receive somatropin

Biological: somatropin - GH treated cohort

somatropin - adult cohort

EXPERIMENTAL

All participants will receive somatropin

Biological: somatropin - adult cohort

Interventions

somatropin - GH naïve pediatric cohort BIOLOGICAL

somatropin 0.245 mg/kg/week

somatropin - GH naïve pediatric cohort

somatropin - GH treated cohort BIOLOGICAL

somatropin 0.084 mg/kg/week

somatropin - GH treated pediatric cohort

somatropin - adult cohort BIOLOGICAL

somatropin 0.084 mg/kg/week

somatropin - adult cohort

Eligibility Criteria

• Age: 0 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Male or female participants with documentation of genetically confirmed diagnosis of PWS.
• No plan to initiate a new treatment that may affect the body composition, such as gonadal hormone replacement therapy.
• Currently on appropriate diet and exercise programs and willing to continue throughout the study period at the discretion of the investigator.
• Participants, and if required by local/site regulations their parent(s)/legal guardian(s) must be willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures.
• Evidence of a personally signed and dated ICD (and written assent where applicable based on age and country regulation) indicating that the participant or a legally acceptable representative/parent(s)/legal guardian has been informed of all pertinent aspects of the study. Refer to Appendix 1 for the detailed process of obtaining consent.
• years or younger.
• Naïve to GH treatment.
• Tanner stage 1 (for testes in males, for breasts in females).
• Participants who are about to complete GH treatment for his/her short stature (eg, due to meeting the treatment stopping criteria defined as a height SDS more than -2.5 for Japanese adult standards).
• years of chronological age or older at Day 1 visit.
• Off from GH treatment for at least 1 year.
• Serum IGF-I level within +2 SDS, adjusted for age and sex.

You may not qualify if:

• Participants with uncontrolled diabetes at the discretion of the investigator.
• Participants with malignant tumors.
• Participants with severe obesity or serious respiratory impairment.
• Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
• Previous administration with an investigational drug within 30 days (or as determined by the local requirement) or 5 half- lives preceding the first dose of study intervention used in this study (whichever is longer).
• Investigator site staff or Pfizer employees directly involved in the conduct of the study, site staff otherwise supervised by the investigator, and their respective family members.

Sponsors & Collaborators

• Pfizer: lead

Study Sites (5)

Kanagawa Children's Medical Center

Yokohama, Kanagawa, 232-8555, Japan

Location

Osaka Women's and Children's Hospital

Izumi, Osaka, 594-1101, Japan

Location

Dokkyo Medical University Saitama Medical Center

Koshigaya, Saitama, 343-8555, Japan

Location

Hamamatsu University Hospital

Hamamatsu, Shizuoka, 431-3192, Japan

Location

National Center for Child Health and Development

Setagaya-ku, Tokyo, 157-8535, Japan

Location

Related Publications (1)

• Kawai M, Murakami N, Horikawa R, Muroya K, Fujisawa Y, Hoshino Y, Okayama A, Sato T, Ebata N, Ogata T. Improvement in body composition of Japanese participants with Prader-Willi syndrome following somatropin treatment: an open-label, multi cohort Phase 3 study. Endocr J. 2025 Aug 1;72(8):925-935. doi: 10.1507/endocrj.EJ24-0659. Epub 2025 May 28.

  PMID: 40436776 DERIVED

Related Links

• To obtain contact information for a study center near you, click here.

MeSH Terms

Conditions

Prader-Willi Syndrome

Condition Hierarchy (Ancestors)

Intellectual Disability; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Abnormalities, Multiple; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Chromosome Disorders; Genetic Diseases, Inborn; Imprinting Disorders; Obesity; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases

Results Point of Contact

• Title: Pfizer ClinicalTrials.gov Call Center
• Organization: Pfizer Inc.

ClinicalTrials.gov_Inquiries@pfizer.com

1-800-718-1021

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 4, 2021
• First Posted: January 6, 2021
• Study Start: February 9, 2021
• Primary Completion: December 6, 2022
• Study Completion: April 15, 2024
• Last Updated: January 14, 2026
• Results First Posted: June 5, 2024

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share

Locations

JP (5)