A study to investigate the safety, pharmacokinetics (PK) and efficacy of garetosmab in children and adolescents with Fibrodysplasia Ossificans Progressiva (FOP).

Phase 3 Evaluation of the Safety, Pharmacokinetics, and Efficacy of Garetosmab (Anti-activin A monoclonal antibody) in Children and Adolescents with Fibrodysplasia Ossificans Progressiva. - OPTIMA-2

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2031250302

Enrollment

Registered

2025-08-20

Start date

2026-06-15

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Fibrodysplasia Ossificans Progressiva (FOP)

Interventions

Drug: Garetosmab Administered per the protocol Other Name: REGN2477

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Participants age criteria are 2 to 30 kg b. Cohort 2 > 30 kg c. Cohort 3 <= 30 kg NOTE: Other protocol-defined Inclusion Criteria applies.

Exclusion criteria

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 Exclusion Criteria Apply.

Design outcomes

Primary

Measure	Time frame
- Occurrence and severity of TEAEs. - Concentrations of functional garetosmab in serum over time	—

Secondary

Measure	Time frame
- Total volume of new HO lesion - Number of new HO lesions - Occurrence of new HO lesions - Number of clinician-assessed flare-ups - Occurrence of clinician-assessed flare-ups - Number of patient/caregiver-reported flare-ups - Occurrence of patient/caregiver-reported flare-ups - Change from baseline in Tanner puberty scale - Characteristics of menstrual cycles for female participants who reached menarche - Height-for-age (5-19 years of age) z-scores over time according to the World Health Organization (WHO) Growth Reference Data for Children - Concentrations of total activin A in serum over time - Occurrence and magnitude of ADA to garetosmab over time - Change from baseline in hearing function as assessed by audiometry - Change from baseline in PedsQL scores - Assessment of acceptability/tolerability via exit interview	—

Measure

Time frame

- Total volume of new HO lesion - Number of new HO lesions - Occurrence of new HO lesions - Number of clinician-assessed flare-ups - Occurrence of clinician-assessed flare-ups - Number of patient/caregiver-reported flare-ups - Occurrence of patient/caregiver-reported flare-ups - Change from baseline in Tanner puberty scale - Characteristics of menstrual cycles for female participants who reached menarche - Height-for-age (5-19 years of age) z-scores over time according to the World Health Organization (WHO) Growth Reference Data for Children - Concentrations of total activin A in serum over time - Occurrence and magnitude of ADA to garetosmab over time - Change from baseline in hearing function as assessed by audiometry - Change from baseline in PedsQL scores - Assessment of acceptability/tolerability via exit interview

—

Countries

France, Italy, Japan, Netherlands, Poland, Spain, United Kingdom, United States

Contacts

Public ContactRosario Chikako

Parexel International Inc.

Clinicaltrial-registration@parexel.com+81-80-8929-3137

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026