A Study Of Safety, Tolerability And Effectiveness Of Recifercept In Children With Achondroplasia
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ClinicalTrials.gov Identifier: NCT04638153 |
Recruitment Status :
Recruiting
First Posted : November 20, 2020
Last Update Posted : November 21, 2022
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Approximately 63 participants will be randomized to one of three doses to receive Recifercept either
- Low Dose
- Medium Dose
- High Dose
Participants will will attend the clinic at baseline and at Day 1, 4, 8, 15, 29 & then Month 2, 3 6, 9 & 12. Assessments include safety, blood sampling, physical examination, vital signs, anthropometric body measurements & patient/caregiver quality of life questionnaires
Participants will received treatment with Recifercept for 12 months. All participants who complete the study and in the opinion of the investigator, continue to have a positive risk:benefit profile, will be offered to enroll into an open-label extension (OLE) study.
A PK cohort will include 12 participants who will randomly receive a single dose of 3 mg/kg of Phase 2 study (process 1c) formulation and a single dose of 3 mg/kg of the proposed Phase 3 (process 2) study formulation in a cross over study. Dose of the cohort could be changed due to emerging safety and efficacy data in the study.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Achondroplasia | Biological: Recifercept | Phase 2 |

Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 63 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Single (Outcomes Assessor) |
Masking Description: | Anthropometric Measurements Assessor |
Primary Purpose: | Prevention |
Official Title: | A PHASE 2 MULTIPLE DOSE, RANDOMIZED STUDY TO ASSESS THE SAFETY, TOLERABILITY, PHARMACOKINETICS AND EFFICACY OF RECIFERCEPT IN CHILDREN WITH ACHONDROPLASIA |
Actual Study Start Date : | December 2, 2020 |
Estimated Primary Completion Date : | January 4, 2024 |
Estimated Study Completion Date : | January 4, 2024 |

Arm | Intervention/treatment |
---|---|
Experimental: Low Dose
Low Dose
|
Biological: Recifercept
Recifercept |
Experimental: Medium Dose
Medium Dose
|
Biological: Recifercept
Recifercept |
Experimental: High Dose
High Dose
|
Biological: Recifercept
Recifercept |
Experimental: PK Phase 2 Formulation
Phase 2 formulation [process 1c] 3mg/kg
|
Biological: Recifercept
Recifercept |
Experimental: PK Phase 3 Formulation
Phase 3 formulation [process 2] 3mg/kg
|
Biological: Recifercept
Recifercept |
- Number of Participants With Treatment Emergent Treatment-Related Adverse Events (AEs) [ Time Frame: Baseline (Day 0) up to 365 days after last dose of study medication ]Treatment-related AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. Serious adverse event (SAE) was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study drug and up to 365 days after last dose that were absent before treatment or that worsened relative to pretreatment state. Relatedness to Recifercept was assessed by the investigator (Yes/No). Participants with multiple occurrences of an AE within a category were counted once within the category.
- Height [ Time Frame: Change in height from baseline up to 365 days after last dose ]Increase in height growth above expected in reference population
- PK Cohort: PK after single doses of 2 formulations [ Time Frame: Baseline to Day 57 ]To evaluate the PK of single subcutaneous doses of 2 formulations (process 1c and process 2) of recifercept
- Number of Participants With Change From Baseline in Vital Signs [ Time Frame: Baseline up to end of treatment (Day 365) ]Following parameters were analyzed for examination of vital signs: systolic and diastolic blood pressure, respiratory rate, radial pulse and body temperature.
- Number of Participants With Change From Baseline in Physical Examination [ Time Frame: Baseline up to end of treatment (Day 365) ]Following parameters were analyzed for examination of systems; A physical examination will include, at a minimum, assessments of the cardiovascular, respiratory, gastrointestinal systems and skin.
- Number of Participants With Laboratory Abnormalities [ Time Frame: Baseline up to end of treatment (Day 365) ]Following parameters were analyzed for laboratory examination: hematology (hemoglobin, hematocrit, red blood cell count, platelet count, white blood cell count, total neutrophils, eosinophils, monocytes, basophils, lymphocytes); blood chemistry (blood urea nitrogen, creatinine, glucose, calcium, sodium, potassium, chloride, total bicarbonate, aspartate aminotransferase, alanine aminotransferase, total bilirubin, alkaline phosphatase, uric acid albumin, total protein)
- Pharmacokinetics - Apparent Clearance (CL/F) [ Time Frame: Day(s) 4, 8, 15, 29, 61, 91, 183, 365 ]Clearance of a drug is a measure of the rate at which a drug is metabolized or eliminated by normal biological processes. Clearance was estimated from population pharmacokinetic (PK) modeling. Drug clearance is a quantitative measure of the rate at which a drug substance is removed from the blood.
- Number of Participants With Anti-Drug Antibody (ADA) [ Time Frame: Baseline up to end of treatment (Day 365) ]The percentage of participants with positive ADA and neutralizing antibodies will be summarized for each treatment arm.
- Change from Baseline in Standing & Sitting Height [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Sitting height/standing height ratio
- Change from Baseline in Arm Span [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Arm span to height/length difference
- Change from Baseline in Lower Leg Length [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Knee height:lower segment ratio
- Change from Baseline in Cranial Face Measurements [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Occipito-frontal circumference
- Change from Baseline in Cranial Face Measurements [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Ratio of occipito-frontal distance to occipito-mid-face measurements
- Change from Baseline in Height [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]z-score of the above height to arm span proportionality and skull morphology where achondroplasia reference datasets exist
- Change from Baseline in Elbow Range of Motion [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Fixed flexion angles at elbow
- Change from Baseline in Body Mass Index [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Body mass index (BMI)
- Change from Baseline in Waist & Chest Circumference [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Waist:chest circumference ratio
- Change from baseline CHAQ questionnaire [ Time Frame: Baseline up to end of treatment (Day 365) in CHAQ component and index scores ]The Childhood Health Assessment Questionnaire (CHAQ) is a 36-item measure of health status and physical function.
- Change from baseline QoLISSY Brief Questionnaire [ Time Frame: Baseline up to end of treatment (Day 365) in QoLISSY Brief total score ]QoLISSY Brief measures health-related quality of life (HRQoL) in children 4-18 years old from the participant and parent perspectives.The 9 items on the QoLISSY Brief were selected from the full QoLISSY physical, social and emotional HRQoL dimensions. The QoLISSY Brief questions ask the participant or caregiver about their status currently. Intended for children or caregivers of children, the instrument uses a 5-point Likert Scale ranging from 'not at all/never' to 'extremely/always'. The QoLISSY Brief total score is the 0-100 transformed sum of the 9 item scores, with higher scores representing better quality of life.
- Change from Baseline in Polysomnography [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Clinical summary of findings (including reported diagnosis);
- Change from Baseline in Polysomnography [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Whether study was performed in room air/oxygen/on continuous positive airway pressure;
- Change from Baseline in Polysomnography [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Apnea-hypopnea index (obstructive and total)
- Change from Baseline in Polysomnography [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Desaturation index (number of desaturations per hour >3% from baseline)
- Change from Baseline in Polysomnography [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Percentage time spent <90% oxygen saturation (SaO2)
- Change from Baseline in Polysomnography [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]Percentage time spent with end-tidal carbon dioxide >50 mmHg
- Change from Baseline in Polysomnography [ Time Frame: Baseline, 3, 6, 9 & 12 Months ]SaO2 nadir
- PK Cohort Adverse Event Monitoring [ Time Frame: Baseline to Day 57 ]To assess the safety and tolerability of single SC doses of 2 formulations (process 1c and process 2) of recifercept

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Ages Eligible for Study: | 3 Months to 10 Years (Child) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Main cohort: Aged ≥2 years to <11 years (up to the day before 11th birthday inclusive) at time of enrollment; or exploratory cohort: aged ≥3 months to <2 years (up to the day before 2nd birthday inclusive) at time of enrollment
- Documented, confirmed genetic diagnosis of achondroplasia from historical medical records prior to entry into this trial (test must have been performed at a laboratory fully accredited for genetic testing under local regulations).
- Completed the C4181001 natural history study with at least 2 valid height/length measurements (at least 3 months apart) prior to enrollment in this study. One of these measurement timepoints must be within the 3 months prior to enrollment in C4181005.
- Tanner stage 1 based on investigator assessment during physical examination (must include assessment of breast development for females, testicular stage for males).
- Able to stand independently for height measurements (if ≥2 years of age at enrollment).
- If aged <2 years at enrollment, has a documented historical MRI brain/cervical spine performed in the previous 12 months.
Exclusion Criteria:
- Presence of co-morbid conditions or circumstances that, in the opinion of the investigator, would affect interpretation of growth data or ability to complete the trial procedures.
- 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.
- Presence of severe obesity (BMI >95th percentile on Hoover-Fong BMI charts) [Hoover-Fong et al, 2008].14
- Known closure of long bone growth plates (cessation of height growth).
- Body weight <7 kg or >30 kg.
- Moderate or severe renal impairment CrCL GFR <60 mL/min/1.73m2 (Calculated GFR based on updated "bedside" Schwartz formula for pediatric patients (CrCL (mL/min/1.73 m2) = 0.413 * Height (cms)/ Serum cr (mg/dL) or hepatic impairment (AST/ALT >1.5 ULN).
- History of hypersensitivity to study intervention or any excipients.
- History of any prior treatment with human growth hormone or related products (including insulin-like growth factor 1 [IGF-1]).
- History of receipt of any treatment that are known to potentially affect growth (including oral steroids >5 days in the last 6 months, high dose inhaled corticosteroids (>800 mcg/day beclametasone equivalent) and medication for attention deficit hyperactivity disorder).
- History of limb lengthening surgery (defined as distraction osteogenesis/Ilizarov/callostasis technique following submetaphyseal osteotomy to extend bone length).
- Any limb lengthening/corrective orthopaedic surgery planned at any point during the trial period.
- Less than 6 months since fracture or surgical procedure of any bone determined from the screening visit date.
- Presence of any internal guided growth plates/devices.
- History of removal of internal guided growth plates/devices within less than 6 months.
- History of receipt of any investigational product for achondroplasia or that may affect growth/interpretation of growth parameters.
- History of receipt of an investigational product (not for achondroplasia/growth affecting) within the last 30 days or 5 half-lives (whichever is longer).

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04638153
Contact: Pfizer CT.gov Call Center | 1-800-718-1021 | ClinicalTrials.gov_Inquiries@pfizer.com |
United States, California | |
Ocean Sleep Medicine | Active, not recruiting |
Aliso Viejo, California, United States, 92656 | |
MemorialCare Sleep Disorders Center at Long Beach Memorial Medical Center | Active, not recruiting |
Long Beach, California, United States, 90806 | |
Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center | Active, not recruiting |
Torrance, California, United States, 90502 | |
United States, Delaware | |
Nemours Alfred I duPont Hospital for Children | Active, not recruiting |
Wilmington, Delaware, United States, 19803 | |
United States, Texas | |
Texas Children's Hospital | Active, not recruiting |
Houston, Texas, United States, 77030 | |
Australia, Victoria | |
Nemours Children's Health - Delaware | Active, not recruiting |
Parkville, Victoria, Australia, 3052 | |
Belgium | |
Universitair Ziekenhuis Antwerpen | Active, not recruiting |
Edegem, Belgium, 2650 | |
Universitaire Ziekenhuizen Leuven (UZ Leuven) | Active, not recruiting |
Leuven, Belgium, 3000 | |
Denmark | |
DanTrials ApS | Active, not recruiting |
Copenhagen NV, Denmark, DK-2400 | |
Italy | |
Fondazione Policlinico Universitario Agostino - Gemelli IRCCS | Active, not recruiting |
Roma, Italy, 00168 | |
Japan | |
Osaka Women's and Children's Hospital | Not yet recruiting |
Izumi, Osaka, Japan, 594-1101 | |
Osaka University Hospital | Recruiting |
Suita-city, Osaka, Japan, 565-0871 | |
Okayama University Hospital | Active, not recruiting |
Okayama, Japan, 700-8558 | |
Portugal | |
Centro Hospitalar e Universitário de Coimbra - Hospital Pediátrico | Active, not recruiting |
Coimbra, Portugal, 3000-602 | |
Spain | |
Hospital Vithas San Jose | Active, not recruiting |
Vitoria-Gasteiz, Alava, Spain, 01008 |
Study Director: | Pfizer CT.gov Call Center | Pfizer |
Responsible Party: | Pfizer |
ClinicalTrials.gov Identifier: | NCT04638153 |
Other Study ID Numbers: |
C4181005 2020-001189-13 ( EudraCT Number ) |
First Posted: | November 20, 2020 Key Record Dates |
Last Update Posted: | November 21, 2022 |
Last Verified: | November 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
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. |
URL: | https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Skeletal Dysplasia |
Achondroplasia Dwarfism Bone Diseases, Developmental Bone Diseases |
Musculoskeletal Diseases Osteochondrodysplasias Genetic Diseases, Inborn |