A Study to Investigate the Safety, Pharmacokinetics (PK), and Efficacy of Garetosmab in Children and Adolescents With Fibrodysplasia Ossificans Progressiva (FOP)

Phase 3Not Yet RecruitingNCT07559513

Regeneron Pharmaceuticals18 enrolled

Overview

This study is researching an experimental drug called garetosmab, referred to as "study drug". The study is focused on children and adolescent participants with FOP. The aim of the study is to see how safe, tolerable, and effective the study drug is. The study is looking at several other research questions, including: * What side effects may happen from taking the study drug * How much study drug is in the blood at different times * Whether the body makes antibodies against the study drug (which could make the study drug less effective or could lead to side effects)

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Fibrodysplasia Ossificans Progressiva (FOP)

Interventions

Eligibility

Sex: ALLMin age: 2 YearsMax age: 18 Years

Medical Language ↔ Plain English

Key Inclusion Criteria: 1. For USA participants, age criteria are 4 to \< 18 years old, at the time of the administration of the first dose of study intervention. Non-USA participants age criteria are 2 to \< 18 years old 2. Must have a confirmation of FOP diagnosis, as described in the protocol 3. At the time of enrollment, participants must weight: 1. Cohort 1 \> 30 kg 2. Cohort 2 \> 30 kg 3. Cohort 3 ≤ 30 kg Key Exclusion Criteria: 1. Cumulative Analog Joint Involvement Scale (CAJIS) score \> 19 at the time of screening 2. Participant has significant concomitant illness or history of significant illness, as described in the protocol 3. Previous history or diagnosis of cancer 4. Ongoing significant viral or bacterial illness, within 2 weeks of the first study drug administration 5. History of severe respiratory compromise requiring oxygen, respiratory support 6. Known history of cerebral vascular malformation 7. Participants with a history of severe, non-traumatic bleeding requiring transfusion or hospitalization for hemodynamic compromise 8. Participants with a known pre-existing medical history of a bleeding diathesis, as described in the protocol NOTE: Other Protocol-defined Inclusion/Exclusion Criteria Apply

Outcomes

Primary Outcomes

Occurrence of Treatment-Emergent Adverse Event (TEAEs)

Time frame: Baseline to week 28

Occurrence of TEAEs

Time frame: Baseline to week 56

Severity of TEAEs

Time frame: Baseline to week 28

Severity of TEAEs

Time frame: Baseline to week 56

Concentrations of functional garetosmab in serum

Time frame: Through week 56

Secondary Outcomes

Total volume of new Heterotopic Ossification (HO) lesion

Time frame: At week 28 and week 56

Number of new HO lesions

Time frame: At week 28 and week 56

Occurrence of new HO lesions

Time frame: At week 28 and week 56

Number of clinician-assessed flare-ups

Time frame: Through week 28 and week 56

Occurrence of clinician-assessed flare-ups

Time frame: Through week 28 and week 56

Number of patient/caregiver-reported flare-ups

Time frame: Through Week 28 and week 56

Occurrence of patient/caregiver-reported flare-ups

Time frame: Through week 28 and week 56

Change from baseline in Tanner puberty scale

Tanner puberty scale or stages: Staging of sexual development is graded on a 5-point ordinal scale ranging from 1 (prepubertal) to 5 (adultlike) for female breast development, male external genitals, and pubic hair

Time frame: At week 28 and week 56

Characteristics of menstrual cycles for female participants who reached menarche

Time frame: Over 28 weeks and 56 weeks

Height-for-age Z-Scores according to the World Health Organization (WHO) Growth Reference Data for Children

Participants 5-19 years of age Z-score represents standardized measure of how far an individual deviated from study cohort average at baseline. A higher Z-score reflects better performance.

Time frame: Through week 56

Concentrations of total activin A in serum

Time frame: Through week 56

Occurence of Anti-Drug Antibody (ADA) to garetosmab

Time frame: Through week 56

Magnitude of ADA to garetosmab

Time frame: Through week 56

Change from baseline in hearing function as assessed by audiometry

Time frame: At week 28 and week 56

Change from baseline in Pediatric Quality of Life inventory (PedsQL) scores

Age-appropriate PedsQL Generic Core Scales will be used to measure HRQoL in children and adolescents. Response options include 5-point Likert scale (or 3-point Likert scale for the young children self-report) for each item asking about experience within the past week. Global scores are transformed to a 0 to 100 scale with higher scores indicating better quality of life.

Time frame: At week 28 and week 56

Acceptability and tolerability assessment via exit interview

Each interview will be conducted by trained external interviewers following a semi-structured interview guide of questions for the participants about their overall experience in the trial.

Time frame: Up to week 30

A Study to Investigate the Safety, Pharmacokinetics (PK), and Efficacy of Garetosmab in Children and Adolescents With Fibrodysplasia Ossificans Progressiva (FOP)

Overview

Conditions

Interventions

Eligibility

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts