Clinical-stage Programs


CSTI-500 is an oral, once-per-day serotonin, dopamine and norepinephrine reuptake inhibitor, or a triple monoamine reuptake inhibitor  (“TRI”). It is under development for the treatment of hyperphagia in PWS, and for hypothalamic obesity (HO). CSTI-500 addresses the dysregulated neurotransmission in the key brain centers in PWS and hypothalamic obesity. It is an optimally balanced TRI with unique pharmacological features that allow for predictable and safe titration to an efficacious dose tailored to the individual patient. CSTI-500 has the potential to provide a transformative therapy, not only for hyperphagia and obesity but also for many of the psychiatric co-morbidities in both diseases.

CSTI-500 was generally safe and well-tolerated and has a half-life of 50 hours in Phase I clinical trials. Also importantly, it demonstrated CNS target engagement via positron emission tomography (PET) that predicts efficacy in patients.

ConSynance plans on initiating a Phase I study (first study in PWS patients) in Q3 2022.


ConSynance holds the exclusive global rights to CSTI-500.


Partnered Program - HBS-102 (formerly CSTI-100) 


Harmony Biosciences holds the full development and commercialization rights globally, with the exception of Greater China.  ConSynance holds the development and commercialization rights in Greater China.​

HBS-102 is an investigational compound being developed as a potential treatment for several rare neurological diseases. HBS-102 is a potential first-in-class molecule with a novel mechanism of action which targets melanin concentrating hormone (MCH) receptor 1 (MCHR1) in the hypothalamus, which makes up the control center for energy regulation, REM sleep, and related behaviors. Harmony is currently evaluating the potential of HBS-102 in a variety of rare neurological areas. For further information please refer to Harmony’s website: