Recruiting
Phase 1
Phase 2

RM-718

Sponsor:

Rhythm Pharmaceuticals, Inc.

Code:

NCT06239116

Conditions

Hypothalamic Obesity

Prader-Willi Syndrome

PWS

Eligibility Criteria

Sex: All

Age: 12 - 65

Healthy Volunteers: Accepted

Interventions

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

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

Part C: RM-718

Part D: RM-718

Study Details

Brief 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

Conditions

Hypothalamic Obesity

Prader-Willi Syndrome

PWS

Study ID

NCT06239116

Start date

Mar 5, 2024

Status verified date

Dec, 2025

Completion date

Nov 1, 2028

Anticipated

Primary completion date

Nov 1, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 12 - 65

Healthy Volunteers: Accepted

Key Inclusion Criteria:

Parts A and B:

  • Male and female subjects in good health aged 18-55 years of age at Screening.
  • Body mass index (BMI) ≥30 kg/m2.
  • Subjects who are medically healthy with normal or clinically insignificant screening results.
  • Subjects must use a highly effective form of contraception 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 informed consent.

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 clinically significant 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 investigational 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 participation in a trial with 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.

Other protocol defined Inclusion/Exclusion criteria may apply.

Study Design

Enrollment

150 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: RM-718 (Cohort A1)

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

experimental: RM-718 (Cohort A2)

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

experimental: RM-718 (Cohort A3)

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

experimental: RM-718 (Cohort A4)

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

experimental: RM-718 (Cohort A5)

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

experimental: RM-718 (Cohort A6)

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

experimental: RM-718 (Cohort A7)

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

experimental: RM-718 (Cohort A8)

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

experimental: RM-718 (Cohort A9)

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

experimental: RM-718 (Cohort B1)

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

experimental: RM-718 (Cohort B2)

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

experimental: RM-718 (Cohort B3)

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

experimental: RM-718 (Cohort B4)

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

experimental: RM-718 (Cohort B5)

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

experimental: RM-718 (Cohort B6)

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

experimental: RM-718 (Cohort C1)

Multiple ascending doses of RM-718 (30)

experimental: RM-718 (Cohort D1)

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

Interventions

Part 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)

Part 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)

Part C: RM-718

Multiple ascending doses of RM-718

Part D: RM-718

Multiple ascending doses of RM-718

Primary outcome measure

  • 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) ]

Central Contacts and Locations

Central contacts

Locations

UAB Pediatric Endocrinology (Part C and Part D)

Recruiting

Birmingham, Alabama, United States, 35233

Ann and Robert H. Lurie Children's Hospital of Chicago (Part C and Part D)

Recruiting

Chicago, Illinois, United States, 60611

Boston Children's Hospital (Part C only)

Recruiting

Boston, Massachusetts, United States, 021115

Brigham and Women's Hospital (Part C and Part D)

Recruiting

Boston, Massachusetts, United States, 02115

Vanderbilt University Medical Center (Part C only)

Recruiting

Nashville, Tennessee, United States, 37232

University of Utah Pediatric Endocrine Clinic (Part C and Part D)

Recruiting

Salt Lake City, Utah, United States, 84112

More Information

Sponsor

Rhythm Pharmaceuticals, Inc.

Last update posted

Dec 22, 2025

Last verified

Dec, 2025

Keywords

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

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Rhythm Pharmaceuticals, Inc. on 2025-12-22.