RENSSELAER, N.Y., June 16, 2026 (GLOBE NEWSWIRE) — ConSynance Therapeutics, Inc. (“ConSynance”), a clinical-stage biotechnology company developing first-in-class therapies for neurobehavioral symptoms in rare neurodevelopmental disorders, today announced that the first participant has been dosed in its Phase 2a clinical trial of CSTI-500 for Prader-Willi syndrome (PWS), marking a significant clinical development milestone for the program.
The Phase 2a study is a proof-of-concept, open-label clinical trial designed to evaluate the safety, tolerability, and exploratory efficacy of CSTI-500 in individuals with PWS. The study is expected to enroll approximately 12 participants aged 13 to 50 years and is being conducted at Vanderbilt University Medical Center.
The study is supported in part by a venture philanthropy investment from the Foundation for Prader-Willi Research (FPWR). FPWR’s venture philanthropy initiative has helped advance multiple clinical-stage therapies for PWS, including one that ultimately led to an FDA-approved treatment.
“Dosing the first patient in our Phase 2a trial is an important milestone for ConSynance and for the PWS community,” said Shuang Liu, PhD, Founder and Chief Executive Officer of ConSynance. “CSTI-500 is designed to affect serotonin, dopamine, and norepinephrine signaling in the brain — neurotransmitters that play important roles in mood regulation, impulse control, and hunger. This study will allow us to further evaluate the safety and tolerability of CSTI-500 in individuals with PWS and to gather early data on its potential to improve hyperphagia, and more notably, the related neurobehavioral symptoms commonly experienced by this population.”
“Data from the Global PWS Registry consistently show that behavioral outbursts and hyperphagia are among the most challenging aspects of PWS for families,” said Theresa Strong, PhD, Director of Research Programs at the Foundation for Prader-Willi Research. “Reaching this clinical milestone with CSTI-500 represents an important step in FPWR’s effort to accelerate the development of therapies that directly address these unmet needs.”
The study will assess CSTI-500 in key clinical areas relevant to PWS, including hyperphagia and neurobehavioral symptoms, using validated measures. Participants will receive individualized doses of CSTI-500 for approximately 84 days, guided by a pharmacokinetic model intended to optimize target engagement and therapeutic response.
CSTI-500 has previously been evaluated in multiple Phase 1 clinical studies involving nearly 100 participants, including individuals with PWS. These studies demonstrated a favorable safety profile and confirmed central nervous system target engagement using positron emission tomography (PET) imaging, supporting advancement into Phase 2 clinical development.
The Phase 2a study (ClinicalTrials.gov Identifier: NCT07348601) will provide important data to inform the future development of CSTI-500.
About Prader-Willi Syndrome
Prader-Willi syndrome (PWS) is a rare, complex genetic neurodevelopmental disorder affecting approximately 1 in 15,000 live births. It is characterized by severe hypotonia and failure to thrive in infancy, followed by the development of life-threatening hyperphagia in early childhood, along with significant neuropsychiatric and behavioral symptoms, including severe temper outbursts. There remains a significant unmet medical need for therapies that address the underlying neurobiological drivers of these symptoms.
About CSTI-500
CSTI-500 is a Phase 2 investigational small-molecule program being developed for PWS and related neurodevelopmental disorders. It is an orally administered triple monoamine reuptake inhibitor designed to simultaneously increase levels of serotonin, dopamine, and norepinephrine in the brain. CSTI-500 has demonstrated brain target engagement in humans and a favorable safety profile in early clinical studies.
About ConSynance Therapeutics
ConSynance Therapeutics is a clinical-stage biotechnology company focused on developing innovative therapies targeting the neurobehavioral dimensions of rare and neurodevelopmental disorders. The company’s approach integrates translational neuroscience and precision dosing strategies to improve clinical outcomes.
For more information, please visit www.ConSynance.com
About the Foundation for Prader-Willi Research (FPWR)
The Foundation for Prader-Willi Research (FPWR) is dedicated to accelerating research that leads to meaningful treatments for people living with Prader-Willi syndrome. Through its venture philanthropy program, FPWR supports promising therapeutic programs with the potential to make a real difference for individuals and families affected by PWS. Financial returns generated from these investments are reinvested into additional research to further advance the field. For more information, please visit www.fpwr.org.
Forward-Looking Statements
This press release contains forward-looking statements based on ConSynance Therapeutics Inc.’s current expectations and beliefs. These statements are subject to various risks and uncertainties, and actual results may differ materially from those described. ConSynance Therapeutics Inc. undertakes no obligation to update or revise any forward-looking statements, except as required by law.
Contact
Sarah Sheldrick, PhD
ConSynance Therapeutics, Inc.
sarah@consynance.com
