Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of OMS1620

A Randomized, Phase 1, Double-blind, Single and Multiple-Ascending Dose and Food Effect Study to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of OMS1620 in Healthy Participants

The goal of this study is to explore the safety, drug concentrations and effects on adrenal gland hormones after a single dose or multiple doses of OMS1620 in healthy participants. In addition, the effect of food on drug concentrations will also be tested.

Study Overview

• Status: Not yet recruiting
• Conditions: Congenital Adrenal Hyperplasia (CAH)
• Intervention / Treatment: Drug: OMS1620; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 84
• Phase: Phase 1

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Key Inclusion Criteria:

• Body mass index (BMI) 18.0 to 32.0 kg/m2 (inclusive) and weight ≥45.0 kg
• Females must be either postmenopausal, surgically sterile or consistently use highly effective methods of contraception from 30 days prior to Day -1 until at least 30 days after the end of the study.
• Females must not be pregnant or lactating
• Males participants who are sexually active with female partners who are females of childbearing potential must use at least two medically effective methods of contraception from Screening through 90 days after the last dose of study drug
• Medically healthy with no significant medical history, physical examination, laboratory, vital signs, or ECG findings, as deemed by the Investigator or qualified designee

Key Exclusion Criteria:

• Use of systemic glucocorticoid therapies within 3 months prior to Screening or use of local glucocorticoid therapies (nasal, topical or inhaled) within 1 month prior to Screening
• Use of mineralocorticoid therapies within 3 months prior to Screening
• Current use of oral hormonal contraceptives. Extended cycle (e.g., ≥3 month) injectable, or implantable hormonal contraceptives are permissible, provided the cycle will not end during the conduct of the study
• Any other condition or prior therapy, that, in the opinion of the Investigator, interferes with the participant's ability to safely complete the study or adhere to study requirements

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Single Ascending Dose (SAD); OMS1620 is an oral small molecule antagonist of the melanocortin 2 receptor (MC2R), the receptor for adrenocorticotrophic hormone (ACTH). OMS1620 or placebo will be given as a single dose.	Drug: OMS1620; OMS1620 is an oral small molecule antagonist of the melanocortin 2 receptor (MC2R), the receptor for adrenocorticotrophic hormone (ACTH); Drug: Placebo; matched placebo control for OMS1620
Experimental: Multiple Ascending Dose (MAD); OMS1620 is an oral small molecule antagonist of the melanocortin 2 receptor (MC2R), the receptor for adrenocorticotrophic hormone (ACTH). OMS1620 or placebo will be given in multiple doses.	Drug: OMS1620; OMS1620 is an oral small molecule antagonist of the melanocortin 2 receptor (MC2R), the receptor for adrenocorticotrophic hormone (ACTH); Drug: Placebo; matched placebo control for OMS1620
Experimental: Food Effect (FE); OMS1620 is an oral small molecule antagonist of the melanocortin 2 receptor (MC2R), the receptor for adrenocorticotrophic hormone (ACTH). OMS1620 or placebo will be given as a single dose on two separate occasions, once while fasted and once with a high-fat meal.	Drug: OMS1620; OMS1620 is an oral small molecule antagonist of the melanocortin 2 receptor (MC2R), the receptor for adrenocorticotrophic hormone (ACTH)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Safety and tolerability as measured by incidence of treatment-emergent adverse events (AEs) and serious adverse events (SAEs)	From Day 1 to approximately day 25
Food Effect (FE) on Pharmacokinetics (PK) of OMS1620 as assessed by maximum concentration (Cmax) in plasma	Two separate assessments (one fasted, one after a high fat meal) of 7 days duration
Food Effect (FE) on Pharmacokinetics (PK) of OMS1620 as assessed by area under the plasma concentration versus time curve (AUC) in plasma	Two separate assessments (one fasted, one after a high fat meal) of 7 days duration

Secondary Outcome Measures

Outcome Measure	Time Frame
Safety and tolerability as measured by incidence of treatment-emergent adverse events (AEs) and serious adverse events (SAEs)	enrollment to approximately Day 25
Pharmacokinetics (PK) of OMS1620 as assessed by maximum concentration (Cmax) in plasma	Day 1 to Day 7 (SAD) or Day 1 to Day 11 (MAD)
Pharmacokinetics (PK) of OMS1620 as assessed by area under the plasma concentration versus time curve (AUC) in plasma	Day 1 to Day 7 (SAD) or Day 1 to Day 11 (MAD)

Other Outcome Measures

Outcome Measure	Time Frame
Pharmacodynamics of OMS1620 as measured by the blood concentrations of adrenal hormone secretion following adrenocorticotrophic hormone (ACTH) stimulation compared to placebo	D 1 (SAD) and Day 10 (MAD)

Collaborators and Investigators

• Sponsor: OMass Therapeutics Australia Proprietary Ltd
• Collaborators: OMass Therapeutics

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: August 10, 2026
• First Submitted That Met QC Criteria: September 5, 2026
• First Posted (Actual): September 9, 2026

Study Record Updates

• Last Update Posted (Actual): September 9, 2026
• Last Update Submitted That Met QC Criteria: September 5, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Endocrine System Diseases; Male Urogenital Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Metabolic Diseases; Gonadal Disorders; Congenital Abnormalities; Adrenal Gland Diseases; Disorders of Sex Development; Urogenital Abnormalities; Steroid Metabolism, Inborn Errors; Adrenogenital Syndrome; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Nutritional and Metabolic Diseases; Adrenal Hyperplasia, Congenital
• Other Study ID Numbers: OMS1620-101

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No