Phase 3 Clinical Trial Evaluating the Efficacy and Safety of Navepegritide and Lonapegsomatropin in Achondroplasia (cAtCH)

November 3, 2026 updated by: Ascendis Pharma A/S

A Phase 3, Randomized, Double-blind, Active Controlled, Multi-center Trial Investigating the Efficacy and Safety of Dual Therapy With Once-weekly Navepegritide and Once-weekly Lonapegsomatropin Compared to Navepegritide Monotherapy and Lonapegsomatropin Monotherapy in Children and Adolescents With Achondroplasia

This pivotal trial is being conducted to evaluate the efficacy, safety and tolerability of dual therapy with navepegritide and lonapegsomatropin administered as separate subcutaneous (SC) injections once weekly in children with achondroplasia (ACH) aged 2 to 17 years.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
144

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

2 years to 17 years (Child)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 1. Age 2 to <18 years at randomization
  • 2. Clinical diagnosis of ACH with historical genetic confirmation
  • 3. At least 1 height measurement available from medical records

Exclusion Criteria:

  • 1. Treatment with growth hormone within 1 year prior to randomization
  • 2. Prior treatment with certain medication(s) which potentially could have affected growth (prior treatment with vosoritide is not exclusive)
  • 3. History of any surgery intended to affect stature, growth, or body proportionality except procedures for leg bowing
  • 4. Unable to stand without assistance
  • 5. Known or suspected medical conditions other than achondroplasia that could affect growth
  • 6. Known history or presence of injury of the growth plates that affects growth potential of long bones
  • 7. Known history or presence of malignant disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Once weekly navepegritide SC and lonapegsomatropin SC
Drug: Dual therapy with navepegritide and lonapegsomatropin

Administered weekly as two separate SC injections. Treatment duration of up to 104 weeks
Experimental: Once weekly navepegritide SC and placebo for lonapegsomatropin SC
Drug: Dual therapy with navepegritide and placebo for lonapegsomatropin

Administered as two separate SC injections. Treatment duration of up to 52 weeks of navepegritide and placebo for lonapegsomatropin followed by 52 weeks of navepegritide and lonapegsomatropin.
Experimental: Once weekly lonapegsomatropin SC and placebo for navepegritide SC
Drug: Dual therapy with lonapegsomatropin and placebo for navepegritide

Administered as two separate SC injections. Treatment duration of up to 52 weeks of lonapegsomatropin and placebo for navepegritide followed by 52 weeks of navepegritide and lonapegsomatropin.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Annualized Growth Velocity (AGV)
Time Frame: 52 weeks

To evaluate the AGV, cm per year, of dual therapy with navepegritide and lonapegsomatropin compared to navepegritide alone
52 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Treatment-emergent Adverse Events (AE)
Time Frame: Throughout trial duration 104 weeks

Number of events
Throughout trial duration 104 weeks
Annualized Growth Velocity (AGV)
Time Frame: 52 weeks

To evaluate the AGV, cm per year, of dual therapy with navepegritide and lonapegsomatropin compared to lonapegsomatroptin alone
52 weeks
Annualized Growth Velocity (AGV) change from baseline
Time Frame: 52 weeks

To evaluate the change from baseline in AGV, cm per year
52 weeks
ACH-specific height Z-score
Time Frame: 52 weeks

To evaluate the change from baseline in ACH-specific height Z-score
52 weeks
CDC-based height Z-score
Time Frame: 52 weeks

To evaluate the change from baseline in CDC-based height Z-score
52 weeks
Bone safety
Time Frame: Throughout trial duration 104 weeks

Qualitative assessment with radiology
Throughout trial duration 104 weeks
Arm span Z-score
Time Frame: 52 weeks

Change from baseline in arm span Z-score.
52 weeks
Upper to lower body segment ratio
Time Frame: 52 weeks

Change from baseline in upper to lower body segment ratio.
52 weeks
Arm span
Time Frame: 52 weeks

Change from baseline in arm span, cm.
52 weeks
Interpedicular distance (IDP)
Time Frame: 52 weeks

Change from baseline in IDP (L1-L4 average), mm
52 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ascendis Pharma A/S

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Medical Director, MD, Ascendis Pharma A/S

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 1, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 30, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 3, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 9, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 3, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ASND0053

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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