AchondroplasiaPhase 2NCT04085523
A Dose Escalation Trial Evaluating Safety, Efficacy, and Pharmacokinetics of TransCon CNP Administered Once Weekly in Prepubertal Children With Achondroplasia
A Phase 2 study testing TransCon CNP in people with Achondroplasia, run by Ascendis Pharma A/S at 15 sites in 8 countries.
Trial summary
The trial is a multicenter, double-blind, randomized, placebo-controlled, dose escalation trial of weekly TransCon CNP administered subcutaneously in prepubertal children 2 to 10 years old, inclusive, with Achondroplasia. Read more about this study
- Who is it for?
- Ages 2 to 10 years
- Conditions the study is for
- Achondroplasia
- What is being tested?
- TransCon CNP
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 57 participants
- Where
- 15 sitesin 8 countries
- Study dates
- 24 Jun 2020to 1 Oct 2024
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 2 to 10 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Clinical diagnosis of ACH with genetic confirmation
- Age between 2 to 10 years old (inclusive) at Screening Visit
- Prepubertal (Stage 1 breasts for girls or testicular volume < 4ml for boys) at Screening Visit
- Able to stand without assistance
- Caregiver willing and able to administer subcutaneous injections of study drug
Who cannot join
- Clinically significant findings at Screening that:
- are expected to require surgical intervention during participation in the trial or
- are musculoskeletal in nature, such as Salter-Harris fractures and severe hip pain or
- otherwise are considered by investigator or Medical Monitor/Medical Expert to make a participant unfit to receive study drug or undergo trial related procedures
- Have received treatment (>3 months) of human growth hormone (hGH) or other medications known to affect stature or body proportionality at any time
- Have received any dose of medications intended to affect stature or body proportionality within the previous 6 months of Screening Visit
- Have received any study drug or device intended to affect stature or body proportionality at any time
- History or presence of injury or disease of the growth plate(s), other than Achondroplasia, that affects growth potential of long bones
Trial locations and contacts
15 sites in 8 countries.
15 sites in 8 countries
United States8 sites
Ascendis Pharma Investigational Site
Aurora, Colorado, 80045
Ascendis Pharma Investigational Site
Buffalo, New York, 14203
Ascendis Pharma Investigational Site
Columbia, Missouri, 65212
Ascendis Pharma Investigational Site
Houston, Texas, 77030
Ascendis Pharma Investigational Site
Little Rock, Arkansas, 72211
Ascendis Pharma Investigational Site
Madison, Wisconsin, 53705
Ascendis Pharma Investigational Site
Saint Paul, Minnesota, 55102
Ascendis Pharma Investigational Site
Seattle, Washington, 98105
Australia1 site
Ascendis Pharma Investigational Site
Parkville, Victoria, 3052
About this study
Official title: ACcomplisH: A Phase 2, Multicenter, Double-blind, Randomized, Placebo-controlled, Dose Escalation Trial Evaluating Safety, Efficacy, and Pharmacokinetics of Subcutaneous Doses of TransCon CNP Administered Once Weekly for 52 Weeks in Prepubertal Children With Achondroplasia Followed by an Open-Label Extension Period
The trial is a multicenter, double-blind, randomized, placebo-controlled, dose escalation trial of weekly TransCon CNP administered subcutaneously in prepubertal children 2 to 10 years old, inclusive, with Achondroplasia.
- Conditions
- Achondroplasia
- Being tested
- TransCon CNP, Placebo for TransCon CNP
- Keywords
- Achondroplasia, Dwarfism
- Medical subject headings
- Achondroplasia, Dwarfism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TransCon CNPDrug
TransCon CNP drug product is a lyophilized powder in a single-use vial containing either TransCon CNP 3.9 mg CNP-38/vial or TransCon CNP 0.80 mg CNP-38/vial. Prior to use, the lyophilized powder is reconstituted with sterile water for injection and administered by subcutaneous injection via syringe and needle.
Placebo for TransCon CNPDrug
Weekly subcutaneously injection of placebo.
| Study group | Role | What they receive |
|---|---|---|
| TransCon CNP 6 mcg | Experimental | TransCon CNP 6 mcg CNP/kg delivered once weekly by subcutaneous injection. Receives: Drug: TransCon CNP |
| TransCon CNP 20 mcg | Experimental | TransCon CNP 20 mcg CNP/kg delivered once weekly by subcutaneous injection. Receives: Drug: TransCon CNP |
| TransCon CNP 50 mcg | Experimental | TransCon CNP 50 mcg CNP/kg delivered once weekly by subcutaneous injection. Receives: Drug: TransCon CNP |
| TransCon CNP 100 mcg | Experimental | TransCon CNP 100 mcg CNP/kg delivered once weekly by subcutaneous injection. Receives: Drug: TransCon CNP |
| Placebo | Placebo comparator | Placebo mimicking 6, 20, 50, or 100 mcg CNP/kg delivered once weekly by subcutaneous injection. Receives: Drug: Placebo for TransCon CNP |
| Open-Label Extension Period: TransCon CNP | Experimental | Participants who completed the 52-week blinded treatment period continued into the 104-week open-label extension period and received treatment with TransCon CNP (navepegritide) doses escalated up to a maximum of 100 mcg/kg delivered once weekly by subcutaneous injection. Receives: Drug: TransCon CNP |
What is being measured
The primary outcome is the main question the study is designed to answer.
Annualized Height Velocity (cm/Year) After 52 Weeks of Double-blind Treatment
The primary efficacy analysis compared the difference in the primary efficacy endpoint between the TransCon CNP treatment group and the pooled placebo group using an ANCOVA model with the annualized height velocity (AHV) at Week 52 as the response variable, treatment (dose groups and placebo) and sex as factors, baseline age and baseline height SDS as the covariates, and based on the Full Analysis Set.
Measured: 52 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Sep 2019
- Study start24 Jun 2020
- Primary completion27 Sep 2022
- Study completion1 Oct 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for AchondroplasiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- There are 5 cohorts enrolling approximately 60 subjects who will be randomized to receive either TransCon CNP or Placebo in a 3:1 ratio
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 57 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ascendis Pharma A/S
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Study Director, MD, Study director, Ascendis Pharma, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04085523
- Sponsor's protocol ID
- TCC-201
- Status last verified
- Jun 2026
- First submitted
- 9 Sep 2019
- Last updated
- 2 Jul 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Savarirayan R, Hoernschemeyer DG, Ljungberg M, Zarate YA, Bacino CA, Bober MB, Legare JM, Hogler W, Quattrin T, Abuzzahab MJ, Hofman PL, White KK, Ma NS, Schnabel D, Sousa SB, Mao M, Smith A, Chakraborty M, Giwa A, Winding B, Volck B, Shu AD, McDonnell C. Once-weekly TransCon CNP (navepegritide) in children with achondroplasia (ACcomplisH): a phase 2, multicentre, randomised, double-blind, placebo-controlled, dose-escalation trial. EClinicalMedicine. 2023 Oct 2;65:102258. doi: 10.1016/j.eclinm.2023.102258. eCollection 2023 Nov.
PubMed 37823031Brod M, McLeod L, Smith A. Assessing signs and impacts of achondroplasia: psychometric evaluation of the Achondroplasia Child Experience Measures. J Patient Rep Outcomes. 2026 Jun 19. doi: 10.1186/s41687-026-01123-z. Online ahead of print.
PubMed 42319555
Study at a glance
From the registry record, last updated by the sponsor on 2 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- ACcomplisH: A Phase 2, Multicenter, Double-blind, Randomized, Placebo-controlled, Dose Escalation Trial Evaluating Safety, Efficacy, and Pharmacokinetics of Subcutaneous Doses of TransCon CNP Administered Once Weekly for 52 Weeks in Prepubertal Children With Achondroplasia Followed by an Open-Label Extension Period
- ClinicalTrials.gov ID
- NCT04085523
- Acronym / sponsor ID
- TCC-201
- Conditions
- Achondroplasia
- Keywords
- Achondroplasia, Dwarfism
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 57 participants (actual)
- Lead sponsor
- Ascendis Pharma A/SIndustry (pharma, biotech, devices)
- Study start
- 24 Jun 2020 (actual)
- Primary completion
- 27 Sep 2022 (actual)
- Study completion
- 1 Oct 2024 (actual)
- First posted
- 11 Sep 2019 (actual)
- Results
- Posted 7 Mar 2024
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The trial is a multicenter, double-blind, randomized, placebo-controlled, dose escalation trial of weekly TransCon CNP administered subcutaneously in prepubertal children 2 to 10 years old, inclusive, with Achondroplasia.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 6
- Model description
- There are 5 cohorts enrolling approximately 60 subjects who will be randomized to receive either TransCon CNP or Placebo in a 3:1 ratio
| Arm | Type | Receives |
|---|---|---|
| TransCon CNP 6 mcg | Experimental | Drug: TransCon CNPTransCon CNP 6 mcg CNP/kg delivered once weekly by subcutaneous injection. |
| TransCon CNP 20 mcg | Experimental | Drug: TransCon CNPTransCon CNP 20 mcg CNP/kg delivered once weekly by subcutaneous injection. |
| TransCon CNP 50 mcg | Experimental | Drug: TransCon CNPTransCon CNP 50 mcg CNP/kg delivered once weekly by subcutaneous injection. |
| TransCon CNP 100 mcg | Experimental | Drug: TransCon CNPTransCon CNP 100 mcg CNP/kg delivered once weekly by subcutaneous injection. |
| Placebo | Placebo comparator | Drug: Placebo for TransCon CNPPlacebo mimicking 6, 20, 50, or 100 mcg CNP/kg delivered once weekly by subcutaneous injection. |
| Open-Label Extension Period: TransCon CNP | Experimental | Drug: TransCon CNPParticipants who completed the 52-week blinded treatment period continued into the 104-week open-label extension period and received treatment with TransCon CNP (navepegritide) doses escalated up to a maximum of 100 mcg/kg delivered once weekly by subcutaneous injection. |
Who may qualify
- Ages
- 2 to 10 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (5 listed)
- Clinical diagnosis of ACH with genetic confirmation
- Age between 2 to 10 years old (inclusive) at Screening Visit
- Prepubertal (Stage 1 breasts for girls or testicular volume < 4ml for boys) at Screening Visit
- Able to stand without assistance
- Caregiver willing and able to administer subcutaneous injections of study drug
Key exclusion criteria (8 listed)
- Clinically significant findings at Screening that:
- Have received treatment (>3 months) of human growth hormone (hGH) or other medications known to affect stature or body proportionality at any time
- Have received any dose of medications intended to affect stature or body proportionality within the previous 6 months of Screening Visit
- Have received any study drug or device intended to affect stature or body proportionality at any time
- History or presence of injury or disease of the growth plate(s), other than Achondroplasia, that affects growth potential of long bones
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| TransCon CNPTransCon CNP drug product is a lyophilized powder in a single-use vial containing either TransCon CNP 3.9 mg CNP-38/vial or TransCon CNP 0.80 mg CNP-38/vial. Prior to use, the lyophilized powder is reconstituted with sterile water for injection and administered by subcutaneous injection via syringe and needle. | Drug | Open-Label Extension Period: TransCon CNP, TransCon CNP 100 mcg, TransCon CNP 20 mcg, TransCon CNP 50 mcg, TransCon CNP 6 mcg |
| Placebo for TransCon CNPWeekly subcutaneously injection of placebo. | Drug | Placebo |
Primary outcome
Annualized Height Velocity (cm/Year) After 52 Weeks of Double-blind Treatment
Time frame: 52 weeks
The primary efficacy analysis compared the difference in the primary efficacy endpoint between the TransCon CNP treatment group and the pooled placebo group using an ANCOVA model with the annualized height velocity (AHV) at Week 52 as the response variable, treatment (dose groups and placebo) and sex as factors, baseline age and baseline height SDS as the covariates, and based on the Full Analysis Set.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Jul 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Results publication: PubMed 37823031Savarirayan R, Hoernschemeyer DG, Ljungberg M, Zarate YA, Bacino CA, Bober MB, Legare JM, Hogler W, Quattrin T, Abuzzahab MJ, Hofman PL, White KK, Ma NS, Schnabel D, Sousa SB, Mao M, Smith A, Chakraborty M, Giwa A, Winding B, Volck B, Shu AD, McDonnell C. Once-weekly TransCon CNP (navepegritide) in children with achondroplasia (ACcomplisH): a phase 2, multicentre, randomised, double-blind, placebo-controlled, dose-escalation trial. EClinicalMedicine. 2023 Oct 2;65:102258. doi: 10.1016/j.eclinm.2023.102258. eCollection 2023 Nov.
- Derived from this study: PubMed 42319555Brod M, McLeod L, Smith A. Assessing signs and impacts of achondroplasia: psychometric evaluation of the Achondroplasia Child Experience Measures. J Patient Rep Outcomes. 2026 Jun 19. doi: 10.1186/s41687-026-01123-z. Online ahead of print.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Study Director, MD study director
Ascendis Pharma, Inc.
15 sites in 8 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing TransCon CNP in people with Achondroplasia, run by Ascendis Pharma A/S at 15 sites in 8 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 2 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 15 sites in United States, Australia, Austria, Denmark, Germany and 3 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 7 Mar 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Annualized Height Velocity (cm/Year) After 52 Weeks of Double-blind Treatment (time frame: 52 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04085523, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jul 2026.