A Study to Learn How Different Injector Pens Affect the Study Medicine Called Genotropin (Somatropin) Delivery and Taken up Into the Blood in Healthy Adults

A PHASE 1, OPEN-LABEL, RANDOMIZED, SINGLE-DOSE, CROSSOVER STUDY TO EVALUATE THE BIOEQUIVALENCE OF TWO DIFFERENT INJECTOR PEN DEVICES FOLLOWING SUBCUTANEOUS ADMINISTRATION OF THE SAME GENOTROPIN® (SOMATROPIN) DOSE IN HEALTHY ADULT PARTICIPANTS

The purpose of this clinical study is to learn about how different injector pens affect:

• how the study medicine (called Genotropin) is delivered into the body and
• how the study medicine is taken up into the blood in healthy adults.

The study is seeking participants who are:

• Aged 18 to 60 years old
• Male or female who are healthy as determined by medical assessment
• Body-mass index (BMI) of 16 to 32, and a total body weight more than 45 kg. BMI is a way to estimate a healthy body weight for an adult's height.

Adults in this study will receive study medicine by a shot under the skin. The study medicine will be given using 2 different injector pens which are medical devices that give a shot under the skin. Blood samples will be taken before and after the shots to look for the study medicine. We will compare the amount of study medicine in the blood between shots from the 2 injector pens.

Adults will take part in this study for about 10 weeks including the screening period. They will have to stay at the study clinic for at least 13 days. This includes 2 study periods in total. A follow up phone call will be made 23 to 30 days following the last study period.

Study Overview

• Status: Recruiting
• Conditions: Healthy
• Intervention / Treatment: Device: Marketed Genotropin Pen 12; Device: New Genotropin Injector Pen; Drug: Genotropin 4mg

• Study Type: Interventional
• Enrollment (Estimated): 26
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Pfizer CT.gov Call Center; Phone Number: 1-800-718-1021; Email: ClinicalTrials.gov_Inquiries@pfizer.com

Study Locations

• Belgium
  • Bruxelles-capitale, Région de
    • Brussels, Bruxelles-capitale, Région de, Belgium, B-1070
      • Recruiting
      • Pfizer Clinical Research Unit - Brussels

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy Participants
• BMI 16 to 32 kg/m2
• body weight more than 45kg

Exclusion Criteria:

• Ongoing or past history of significant medical conditions
• Use of prescription or non prescription medications within 14 days of first study dose
• Previous exposure to growth hormone
• History of alcohol abuse, binge drinking or illicit drug use

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sequence 1; Single dose of 4 milligrams (mg) subcutaneous genotropin via marketed genotropin pen 12 (Reference) followed by single dose of 4mg subcutaneous genotropin via new genotropin injector pen (Test)	Device: Marketed Genotropin Pen 12; Growth Hormone Delivery Device for use with Somatropin for injection; Device: New Genotropin Injector Pen; Growth Hormone Delivery Device for use with Somatropin for injection; Drug: Genotropin 4mg; 4mg subcutaneous; Other Names: Somatropin
Experimental: Sequence 2; Single dose of 4mg subcutaneous genotropin via new genotropin injector pen (Test) followed by single dose of 4mg subcutaneous genotropin via marketed genotropin pen 12 (Reference)	Device: Marketed Genotropin Pen 12; Growth Hormone Delivery Device for use with Somatropin for injection; Device: New Genotropin Injector Pen; Growth Hormone Delivery Device for use with Somatropin for injection; Drug: Genotropin 4mg; 4mg subcutaneous; Other Names: Somatropin

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area Under the Concentration-time Curve From Time Zero Extrapolated to Infinity (AUCinf) of Somatropin	AUCinf = Area under the plasma concentration versus time curve (AUC) from time zero (pre-dose) to extrapolated infinite time (0-inf). It is obtained from AUC (0-t) plus AUC (t-inf).	At pre-dose -24, -18, -12, -8, 0 and 1, 2, 3, 4, 6, 8, 10, 12, 16 and 24 hours post-dose on day 1 of each period
Maximum Observed Plasma Concentration (Cmax) for Somatropin		At pre-dose -24, -18, -12, -8, 0 and 1, 2, 3, 4, 6, 8, 10, 12, 16 and 24 hours post-dose on day 1 of each period

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Treatment Emergent Adverse Events		From start of study treatment up to 28-35 days after last dose of study treatment (41 days)
Number of Participants With Clinical Laboratory Abnormalities		Up to Day 11
Area under the effect-time curve from 0 to time of last measurable concentration (AUEClast)	Area under the effect-time curve to the last observed time point of Serum IGF-1	At pre-dose and 6, 12, 24, 48, 72 and 96 hours post-dose on day 1 of each period
Maximum observed effect (Emax)	Maximum observed effect of Serum IGF-1	At pre-dose and 6, 12, 24, 48, 72 and 96 hours post-dose on day 1 of each period

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

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

Study record dates

Study Major Dates

• Study Start (Actual): April 22, 2026
• Primary Completion (Estimated): June 25, 2026
• Study Completion (Estimated): July 22, 2026

Study Registration Dates

• First Submitted: April 14, 2026
• First Submitted That Met QC Criteria: April 14, 2026
• First Posted (Actual): April 21, 2026

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 8, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: adult; bioequivalence; genotropin
• Additional Relevant MeSH Terms: Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Peptide Hormones; Peptides; Amino Acids, Peptides, and Proteins; Pituitary Hormones; Growth Hormone; Pituitary Hormones, Anterior; Human Growth Hormone
• Other Study ID Numbers: A6281331; 2026-525165-52-00 (Registry Identifier: CTIS (EU))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No