NCT05587712 · Merck Sharp & Dohme LLC
Study to Evaluate Sotatercept (MK-7962) in Children With Pulmonary Arterial Hypertension (PAH) (MK-7962-008)
(MOONBEAM)
What this study is about
The primary objectives of the study are to evaluate the safety and how well patients handle the treatment, and how the drug moves through the body (PK) of sotatercept over 24 weeks of treatment in children ≥1 to \<18 years of age with PAH World Health Organization (WHO) Group 1 on the usual treatment (SoC). There is no formal hypothesis.
View original scientific description
The primary objectives of the study are to evaluate the safety and tolerability, and pharmacokinetics (PK) of sotatercept over 24 weeks of treatment in children ≥1 to \<18 years of age with PAH World Health Organization (WHO) Group 1 on standard of care (SoC). There is no formal hypothesis.
Interventions
DRUG
Sotatercept
SC injection every 3 weeks (Q3W) of 0.3 mg/kg. Dosage may be adjusted based on protocol-specific guidelines.
Primary outcome measures
Serum Trough Concentration (Ctrough) of Sotatercept
Time frame: Predose Day 1, Day 21, Day 42, Day 63, Day 84, Day105, Day 126, Day 147, Day 168, Day 189. Postdose Day 7, Day 14, Day 64, Day 69 and Day 76
Ctrough was the lowest concentration of Sotatercept in serum just before the next dose. Blood samples will be collected at multiple time points to estimate the Ctrough of Sotatercept.
Area Under the Curve at Steady State (AUCss) of Sotatercept
Time frame: Predose Day 1, Day 21, Day 42, Day 63, Day 84, Day105, Day 126, Day 147, Day 168, Day 189. Postdose Day 7, Day 14, Day 64, Day 69 and Day 76
Blood samples will be collected at multiple time points to estimate the AUCss of Sotatercept.
Area Under the Curve from 0 to 3 weeks (AUC0-3 weeks) of Sotatercept
Time frame: Predose Day 1, Day 7, Day 14, and Predose Day 21
Blood samples will be collected at Predose Day 1, Day 7, Day 14, and Predose Day 21 to estimate the AUC0-3 weeks of Sotatercept.
Percentage of Participants Who Experience at Least 1 Adverse Event (AE)
Time frame: Up to 24 weeks
An AE is any unfavourable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an AE. The percentage of participants with 1 or more AEs will be assessed.
Percentage of Participants Who Discontinue Study Drug Due to an AE
Time frame: Up to 24 weeks
An AE is any unfavourable and unintended sign, symptom, or disease temporally associated with the use of a medicinal product or protocol-specified procedure, whether or not considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition considered related to the medicinal product or protocol-specified procedure. Any worsening of a preexisting condition that is temporally associated with the use of the Sponsor's product, is also an adverse event. The percentage of participants who discontinued the study drug due to an AE regardless of study completion status will be assessed.
Laboratory Parameter (Hematology): Concentration of Hemoglobin
Time frame: Up to 24 weeks
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The concentration of hemoglobin will be presented.
Laboratory Parameter (Hematology): Hematocrit
Time frame: Up to 24 weeks
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The hematocrit will be presented.
Laboratory Parameter (Hematology): Red Blood Cell (RBC) Count
Time frame: Up to 24 weeks
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The RBC count will be presented.
Laboratory Parameter (Hematology): Reticulocyte Count
Time frame: Up to 24 weeks
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The reticulocyte count will be presented.
Laboratory Parameter (Hematology): Platelet Count
Time frame: Up to 24 weeks
Hematological parameters will be investigated in blood samples from participants by means of clinical laboratory assays and evaluated by the investigator. The platelet count will be presented.
Blood Pressure (BP)
Time frame: Up to 24 weeks
BP will be assessed while the participant was seated after a period of rest in a quiet setting with no distractions (eg, television and cell phones).
Titer of Anti-drug Antibody (ADA) to Sotatercept
Time frame: Up to 24 weeks
ADA to Sotatercept will be assessed.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Documented, historic diagnostic right heart catheterization (RHC) any time before Screening confirming the diagnosis of PAH WHO Group 1 in any of the following subtypes:
- Idiopathic pulmonary arterial hypertension (IPAH)
- Heritable PAH
- Drug/toxin-induced PAH
- PAH associated with connective tissue disease
- PAH-congenital heart disease (CHD) with shunt closure \>6 months before Screening and subsequently confirmed by RHC before Screening
- PAH with coincidental shunt.
- Must be on a stable dose(s) of background PAH therapy (phosphdiesterase-5 (PDE5) inhibitors, endothelin receptor antagonists (ERAs), soluble guanylate cyclase stimulators (sGCS), or prostanoids \[including subcutaneous and intravenous\])
- If male, agree to the following during the intervention period and for at least 16 weeks (112 days) after the last dose of study intervention:
- Abstains from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long-term and persis
Where
- Los Angeles, California
- Palo Alto, California
- San Francisco, California
- Aurora, Colorado
- Washington D.C., District of Columbia
- Cincinnati, Ohio
- Philadelphia, Pennsylvania
- Nashville, Tennessee
- Seattle, Washington
- Milwaukee, Wisconsin
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 20, 2026 · Source of record for eligibility and locations