A sulfur-based, small-molecule discovery platform
Thiopeutics’ discovery platform is built around sulfur-containing (thiol-based) small molecules designed to correct the cellular and physiological disruptions caused by opioid overdose. Our lead candidate, D-cysteine ethyl ester (D-CYSee), is a cell-penetrant thiol ester engineered for rapid delivery of D-cysteine to central respiratory control pathways.
Target indications
Our discovery-stage research program is focused on two related indications: Opioid-Induced Respiratory Depression (OIRD) and Opioid-Induced Respiratory Arrest and Depression (ORAARD). Both arise from opioid suppression of brainstem ventilatory drive and represent a leading cause of fatal overdose.
Mechanism of action
Unlike opioid receptor antagonists, which reverse respiratory depression by displacing opioids from their receptors and thereby stripping away analgesia and precipitating acute withdrawal, D-CYSee acts through a distinct, receptor-independent pathway. In preclinical models, D-CYSee restores cellular redox balance and ventilatory drive, correcting minute ventilation and arterial blood-gas chemistry while preserving the analgesic effect of the opioid.
This differentiated mechanism positions D-CYSee as a potential adjunct or alternative countermeasure that addresses a key limitation of current standard-of-care antagonist therapy.
Scientific origins
Our science originates in the Lewis Lab at Case Western Reserve University, where the respiratory pharmacology behind D-CYSee was first characterized and where thiol-based correction of opioid-driven ventilatory failure was first demonstrated in vivo. We continue to work closely with the lab, drawing on its expertise in brainstem ventilatory control, arterial blood-gas physiology, and thiol redox chemistry to shape the direction of our discovery program.
Why a sulfur-chemistry platform
Thiol ester small molecules offer several practical advantages as a development platform: well-understood synthetic routes, favorable manufacturing scalability, and the ability to tune pharmacokinetic properties through ester modification. These characteristics support a capital-efficient path from discovery through IND-enabling studies.
Thiopeutics’ programs are in the discovery stage. Findings described here are derived from in vivo and in vitro preclinical research and have not been evaluated in human clinical trials.