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Active, not recruitingNCT06239116Updated Oct 9, 2026

A Study of RM-718 in Healthy Subjects and Patients With MC4R Pathway Impairment

A Phase 1/2 interventional study of Part A: RM-718 or placebo (matched to specific RM-718 dose cohort) and Part B: RM-718 or placebo (matched to specific RM-718 dose cohort) in Hypothalamic Obesity, Prader-Willi Syndrome and PWS, sponsored by Rhythm Pharmaceuticals, Inc.. Active, not recruiting at 7 sites in United States. Open to participants aged 12 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-09.

Sponsored by Rhythm Pharmaceuticals, Inc. · Phase 1/2, Interventional, and Treatment

Updated Oct 9, 2026Now Active, not recruitingPrimary completion moved+2 moreGo to Updates ↓
Phase
Phase 1/2
Study type
Interventional
Enrollment
111
Allocation
Randomized
Ages
12 Years to 65 Years
Sex
All
01

Where this study stands

Counted across the records on this site · 2026-11-12

Among 14 studies in Sexual Infantilism with a site in United States — 3 open to participants now, 6 under way, 2 of them phase 3. Sexual Infantilism · United States.

Enrollment
2nd of 14
111 · median 27
Started
2024
with 2 others
Phase 1/2
2 of 14
none open now
Registered
9th of 14
by date
Lead sponsor
7 of 14
Rhythm Pharmaceuticals, Inc.

Among the 14 studies in Sexual Infantilism with a site in United States, this one is the 2nd largest by enrollment, is one of 3 that started in 2024, is one of 2 in phase 1/2, and was the 9th registered.

Sexual Infantilism

23 studies on the registry are indexed under Sexual Infantilism; 5 are open to participants now.

Browse Sexual Infantilism studies →

Open to participants now

3 of the 14 studies in Sexual Infantilism with a site in United States are open now. Recruiting first, the newest first:

All 3 open studies →

A study can be open while its sites in United States have not opened yet or have stopped. Only those recruiting at a site in United States →

Who these studies take

Of the 3 Sexual Infantilism studies recruiting now, 2 (67%) set no upper age limit and 1 (33%) stop at 75 or younger; 1 take children under 18; 0 take healthy volunteers.

This study: 12 Years to 65 Years · all sexes · healthy volunteers too.

The full table on the hub →

This tab as a report to print or save as PDF → With an account.

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Watch this landscapeDownload CSVNarrow it in search →With an account: a weekly mail of what changed among 14 studies in Sexual Infantilism with a site in United States, or all of them as a file.
02

Study summary

The purpose of this study is to evaluate the safety, tolerability, and PK of RM-718 in healthy subjects with obesity and in patients with MC4R Pathway Impairment

Read the detailed description

This is a first-in-human and first-in-patient, 4-part study that includes the evaluation of safety, tolerability, and PK of: single ascending doses (SAD) of RM-718 weekly (RM-718) in healthy subjects 18 to 55 years of age with obesity (Part A), multiple ascending doses (MAD) of RM-718 in healthy subjects 18 to 55 years of age with obesity (Part B), MAD of RM-718 in patients 12 to 65 years of age with HO (Part C), and MAD of RM-718 in patients with PWS (Part D). Cohorts in Parts A and B are double-blind, placebo-controlled, and randomized 2:1 (4 subjects receive RM-718, 2 subjects receive placebo). Part C evaluates open-label dose escalation in patients 12 to 65 years of age with HO. Part D evaluates open-label dose escalation in patients 12 to 65 years of age. Study participants will receive: 1 weekly dose of either RM-718 or placebo in Part A, 4 weekly doses of either RM-718 or placebo in Part B,16 weekly doses of open-label RM-718 in Part C, and 26 weekly doses of RM-718 in Part D. Study drug (RM-718 or placebo) doses are administered weekly via subcutaneous injection.

03

Conditions studied

  • Hypothalamic Obesity
  • Prader-Willi Syndrome
  • PWS

Keywords

  • melanocortin 4 receptor (MC4R)
  • MC4R agonism
  • obesity
04

Who can participate

The criteria were revised on the registry on Oct 9, 2026. See what changed

Ages eligible
12 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Eligibility criteria

Key Inclusion Criteria:

Parts A and B:

  • Male and female subjects in good health aged 18-55 years of age at Screening.
  • (BMI) ≥30 kg/m2.
  • Subjects who are medically healthy with normal or clinically insignificant screening results.
  • Subjects must use a highly effective form of and follow the study contraception requirements.
  • Ability to communicate well with the Investigator, understand and comply with the requirements of the trial, and understand English and sign the written .

Part C:

  • Male and female patients with HO, aged 12-65 years of age at Screening.

  • Patient has documented evidence of acquired HO defined as:

    • Diagnosis of craniopharyngioma or other brain lesion affecting the hypothalamic region and has undergone surgery, or chemotherapy, or radiation therapy involving the hypothalamus at least 6 months before Screening, OR
    • Documented injury to the hypothalamus at least 6 months before Screening for which surgery/radiation is not indicated.
  • Weight gain associated with the hypothalamic injury either before or following therapy (surgery and/or following chemotherapy or radiotherapy), and a BMI of ≥30 kg/m2 for patients ≥18 years of age or BMI ≥95th percentile for age and sex for patients 12 to \<18 years of age.
  • Patients must use a highly effective form of contraception and follow the study contraception requirements.
  • Ability to communicate with the Investigator, understand and comply with the requirements of the trial, and understand and sign the written informed consent and assent (for patients aged \<18 years), and informed consent for a parent or guardian of any patient \<18.

Part D:

  • Confirmed diagnosis of PWS as determined by the Investigator at the time of Screening.
  • Age ≥12 to 65, inclusive, at the time of signing Informed Consent and/or Assent.
  • BMI ≥30 kg/m2 for patients ≥18 years of age or BMI ≥95th Percentile for age and sex for patients \<18 years of age based on the US CDC criteria.
  • Able to meet contraception requirements.

Key Exclusion Criteria:

Parts A and B

  • Any abnormalities on screening laboratories or physical examination as determined by the Investigator.
  • Active or history of any significant medical condition such as and including renal, hepatic, pulmonary, gastrointestinal, cardiovascular, genitourinary, endocrine, immunologic, metabolic, neurologic or hematological disease.
  • Obesity due to genetic, syndromic, or endocrine etiologies.
  • History of renal transplant, end stage renal disease.
  • Diagnosis of severe psychiatric disorders.
  • Current, clinically significant pulmonary, cardiac, metabolic, or oncologic disease considered severe enough to interfere with the trial and/or confound the results.
  • Cigarette smoking or dependence on caffeine, alcohol or drugs; unable or unwilling to abstain completely from caffeine, alcohol and related substances for 24 hours prior to and after study visits.
  • History of recent surgery (within 60 days of Screening).
  • Participation in any clinical trial with an drug/device within 3 months or 5 half-lives, whichever is longer, prior to the first trial dose.
  • Pregnant and/or breastfeeding or desiring to become pregnant during this trial.

Part C

  • Diagnosis of Prader-Willi syndrome (PWS) or Rapid-onset obesity with hypoventilation, hypothalamic, autonomic dysregulation, neuroendocrine tumor syndrome (ROHHADNET).
  • Weight loss >2% in the previous 3 months for patients aged ≥18 years or >2% reduction in BMI for patients aged 12 to \<18 years and/or anti-obesity medications for the treatment of obesity.
  • Bariatric surgery or procedure within the last 2 years.
  • Diagnosis of severe psychiatric disorders; any suicidal ideation, attempt or behavior.
  • Current, clinically significant pulmonary, cardiac, metabolic, or oncologic disease considered severe enough to interfere with the trial and/or confound the results.
  • History of renal transplant, end stage renal disease.
  • Participation in any clinical trial with an investigational drug/device within 3 months or 5 half-lives, whichever is longer, prior to the first trial dose, or previous use of setmelanotide.
  • Pregnant and/or breastfeeding or desiring to become pregnant during this trial.
  • Obesity attributable to other genetic or syndromic conditions (eg, PPL [pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), leptin receptor (LEPR), collectively], Bardet-Biedl syndrome [BBS]) prior to the hypothalamic injury.

Part D

  • Weight loss >2% in the previous 3 months for patients aged ≥18 years or >2% reduction in BMI for patients aged 12 to \<18 years or therapies for the treatment of obesity or hyperphagia.
  • Metabolic and bariatric surgery (MBS) or procedure within last 6 months.
  • Diagnosis of severe psychiatric disorders; any suicidal ideation, attempt or behavior.
  • Current, clinically significant pulmonary, cardiac, metabolic, or oncologic disease considered severe enough to interfere with the trial and/or confound the results.
  • Pregnant and/or breastfeeding or desiring to become pregnant during this trial.
  • Participation in any clinical trial with an investigational drug/device within 3 months or 5 half-lives, whichever is longer, prior to the first trial dose, or previous use of setmelanotide.

Other protocol defined Inclusion/Exclusion criteria may apply.

Terms in these criteria, in plain language(5)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Triple (Participant, Care provider, Investigator)
Enrollment
111 participants (actual)

Study arms

  • Experimental
    RM-718 (Cohort A1)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort A2)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort A3)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort A4)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort A5)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort A6)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort A7)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort A8)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort A9)

    Single dose of RM-718 (4) or placebo (2)

    Drug: Part A: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort B1)

    Multiple ascending doses of RM-718 (4) or placebo (2)

    Drug: Part B: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort B2)

    Multiple ascending doses of RM-718 (4) or placebo (2)

    Drug: Part B: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort B3)

    Multiple ascending doses of RM-718 (4) or placebo (2)

    Drug: Part B: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort B4)

    Multiple ascending doses of RM-718 (4) or placebo (2)

    Drug: Part B: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort B5)

    Multiple ascending doses of RM-718 (4) or placebo (2)

    Drug: Part B: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort B6)

    Multiple ascending doses of RM-718 (4) or placebo (2)

    Drug: Part B: RM-718 or placebo (matched to specific RM-718 dose cohort)

  • Experimental
    RM-718 (Cohort C1)

    Multiple ascending doses of RM-718 (30)

    Drug: Part C: RM-718

  • Experimental
    RM-718 (Cohort D1)

    Multiple ascending doses of RM-718 (up to 30)

    Drug: Part D: RM-718

Interventions

  • DrugPart A: RM-718 or placebo (matched to specific RM-718 dose cohort)

    Single ascending dose of RM-718 or placebo (matched to specific RM-718 Part A dose cohort)

  • DrugPart B: RM-718 or placebo (matched to specific RM-718 dose cohort)

    Multiple ascending doses of RM-718 or placebo (matched to specific RM-718 Part B dose cohorts)

  • DrugPart C: RM-718

    Multiple ascending doses of RM-718

  • DrugPart D: RM-718

    Multiple ascending doses of RM-718

06

What researchers measure

Primary outcomes

  1. Parts A, B, C, D: Safety and Tolerability Assessed by Number of Study Participants with Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)

    Time frame: From Day 1 through the Safety-Follow-up call (up to Day 43 for all Part A cohorts, up to Day 70 for all Part B cohorts, up to Day 140 for Part C cohort, up to Day 210 for Part D cohort)

Secondary outcomes

  1. AUCtau measurement of RM-718

    Area under the concentration versus time curve during a dosing interval

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  2. Cmax measurement of RM-718

    Maximum concentration measurement of RM-718 in plasma

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  3. Cmin measurement of RM-718

    Minimum plasma concentration of RM-718 reached during dosing interval

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  4. Tmax measurement of RM-718

    Time it takes for RM-718 to reach the maximum concentration (Cmax)

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  5. Tmin measurement of RM-718

    Time at which the lowest concentration value of RM-718 is observed

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  6. Ctrough measurement of RM-718

    Observed pre-dose plasma concentration of RM-718

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  7. Cavg measurement of RM-718

    Average concentration of RM-718 during a dosing interval in steady state

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  8. t1/2 measurement of RM-718

    Terminal elimination half-life of RM-718 in plasma

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  9. λz measurement of RM-718

    Estimate of the terminal elimination rate constant of RM-718

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  10. CL/F measurement of RM-718

    Clearance of RM-718 following extravascular administration

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  11. Vz/F measurement of RM-718

    Volume of distribution of RM-718 following extravascular administration

    Time frame: up to 168 hours post-dose on Day 1 (Parts A, B and C) and 168 hours post-dose on Day 22 (Parts B and C).

  12. Accumulation ratio of RM-718

    Ratio of accumulation of RM-718 under steady state conditions

    Time frame: Week 1 to Week 4 (AUC on Week 4/AUC on Week 1) (Parts B, C)

  13. Change from baseline in BMI (Part C only)

    Time frame: Baseline to Week 16

  14. Mean change in weight (Part C only)

    Time frame: Baseline to Week 16

  15. Mean change in waist circumference (Part C only)

    Time frame: Baseline to Week 16

  16. Mean change in weekly average of the daily most hunger score in patients ≥12 years of age (Part C only)

    Time frame: Baseline to Week 16

  17. Mean change in weekly average of the Symptoms of Hyperphagia composite score (Part C only)

    Time frame: Baseline to Week 16

  18. Ctrough measurement of RM-718 (Part D)

    Observed pre-dose plasma concentration of RM-718

    Time frame: up to 168 hours post-dose on Day 8 and up to 168 hours post-dose on Day 29

  19. Change from baseline in BMI (Part D)

    Time frame: Baseline to Week 26

  20. Mean change in weight (Part D)

    Time frame: Baseline to Week 26

  21. Mean change in waist circumference (Part D)

    Time frame: Baseline to Week 26

  22. Mean change in the weekly average of the Prader-Willi Syndrome Food Problem Diary (PWS-FPD) total score (Part D)

    Time frame: Baseline to Week 26

  23. Mean change in the Hyperphagia Questionnaire for Clinical Trials (HQ-CT) total score (Part D)

    Time frame: Baseline to Week 26

  24. Change in total body mass (Part D)

    Change in body mass as measured by dual-energy x-ray

    Time frame: Baseline to Week 26

07

Study locations

7 sites
  • UAB Pediatric Endocrinology (Part C and Part D)
    Birmingham, Alabama 35233, United States
  • Ann and Robert H. Lurie Children's Hospital of Chicago (Part C and Part D)
    Chicago, Illinois 60611, United States
  • Boston Children's Hospital (Part C only)
    Boston, Massachusetts 021115, United States
  • Brigham and Women's Hospital (Part C and Part D)
    Boston, Massachusetts 02115, United States
  • Vanderbilt University Medical Center (Part C only)
    Nashville, Tennessee 37232, United States
  • Worldwide Clinical Trials (Part A and Part B)
    San Antonio, Texas 78217, United States
  • University of Utah Pediatric Endocrine Clinic (Part C and Part D)
    Salt Lake City, Utah 84112, United States
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

1 registry update since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedDate before it movedWhere the date was before it moved

Started Mar 2024 (actual). Primary completion is estimated for May 2027, 38 months after the start.

Primary completion moved once since we started tracking on Sep 25, 2026: Nov 2027 → May 2027, on Oct 9, 2026.

Earlier changes are on the record history on ClinicalTrials.gov ↗

How these figures are worked out, and which studies are left out of them.

Registered
Jan 25, 2024
First posted
Feb 2, 2024
StartActual
Mar 5, 2024
Primary completionEst.
May 7, 2027was Nov 2027
CompletionEst.
Nov 1, 2028
Last update
Oct 9, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Status
Recruiting→Active, not recruiting
changed Oct 9, 2026
Primary completion
Nov 1, 2027→May 7, 2027
Oct 9, 2026
Enrollment
150 (estimated)→111 (actual)
Oct 9, 2026
Eligibility
1 criterion edited, 1 added
What changed in the criteria
  • EditedParticipation in any clinical trial with an investigational drug/device within 3 months or 5 half-lives, whichever is longer, prior to the first trial dose, or previous participation in a trial withuse of setmelanotide.
  • AddedParticipation in any clinical trial with an investigational drug/device within 3 months or 5 half-lives, whichever is longer, prior to the first trial dose, or previous use of setmelanotide.
Oct 9, 2026
Show all 1 update
  1. Oct 9, 2026
    Recruiting→Active, not recruiting
    Primary completion Nov 1, 2027→May 7, 2027
    Enrollment 150 (estimated)→111 (actual)
    Eligibility 1 criterion edited, 1 added
    What changed in the criteria
    • EditedParticipation in any clinical trial with an investigational drug/device within 3 months or 5 half-lives, whichever is longer, prior to the first trial dose, or previous participation in a trial withuse of setmelanotide.
    • AddedParticipation in any clinical trial with an investigational drug/device within 3 months or 5 half-lives, whichever is longer, prior to the first trial dose, or previous use of setmelanotide.
    + 3 other changes: verification date, contact details and site details

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT06239116
Lead sponsor
Rhythm Pharmaceuticals, Inc.
Responsible party
Sponsor
First posted
Feb 2, 2024
Start date
Mar 5, 2024
Primary completion
May 7, 2027 (estimated)
Completion
Nov 1, 2028 (estimated)
Last update
Oct 9, 2026

Study contacts

David Meeker
study chair · Rhythm Pharmaceuticals, Inc.

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.

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