Armgo Pharma has raised $35 million from venture capital investors to progress the clinical development of its lead asset, ARM210, for the treatment of catecholaminergic polymorphic ventricular tachycardia (CPVT), a rare form of ventricular tachycardia (rapid heartbeat arising from abnormal electrical signals in the ventricles), as well as other cardiac and skeletal muscle indications. Phase II studies in CPVT are due to start before the end of this year.
CPVT is a rare, life-threatening disease predominately caused by mutations in ryanodine receptor 2 (RyR2), the major Ca2+ release channel on the sarcoplasmic reticulum in cardiomyocytes. Due to these mutations, the RyR2 channels become leaky, which leads to dysregulated Ca2+ homeostasis and severe ventricular arrhythmia. Initial onset typically occurs in childhood, with patients presenting with exercise or emotionally induced palpitations or syncope (fainting) associated with a high incidence of sudden cardiac death.
Early recognition and management of CPVT is imperative as the condition has an untreated mortality rate of 30–50% by the age of 40. Beta blockers such as nadolol, which are administered with the aim of reducing the heart rate, represent the current standard of care. While these drugs are effective for most patients, a significant minority of patients treated with beta blockers continue to experience serious clinical events such as cardiac arrest, placing them at risk of sudden cardiac death. Consequently, there is a strong unmet need for alternative novel therapeutics in CPVT.
The progression of ARM210, a once-daily oral pill, to Phase II trials represents an exciting development as this drug has the potential to be the first disease-modifying therapy in CPVT. ARM210 is thought to stabilise arrhythmia by enhancing the binding of calstabin to RyR2 channels, which alleviates Ca2+ leakage and restores Ca2+ homeostasis. Initial safety and efficacy data from preclinical and early clinical studies appear promising, raising hopes that ARM210 could prove to be a highly effective therapy, even among patients who respond inadequately to standard therapies.
R&D investment in CPVT is limited, which reflects the rarity of the condition, as well as gaps in understanding of disease mechanisms. However, according to GlobalData’s pipeline product database, there are currently three other products in development for CPVT, all of which are novel, orally administered drugs. These include a second drug candidate in development by Armgo Pharma and a therapy in development by Elex Biotech, both of which are currently in preclinical development. These drugs employ similar mechanisms to ARM210 as they directly target leaky channels in order to reduce Ca2+ leakage and improve Ca2+ homeostasis. A third candidate, which is currently at the discovery stage of development by GEXVal, acts by an undisclosed mechanism of action.
Due to the early development stage, there is a great deal of uncertainty regarding the long-term safety and efficacy of all these therapies. However, the modest pipeline does at least offer hope for a new era of disease-modifying therapy within the next decade, a much-needed development for this often-deadly disease.