Benzinga | Jun 28, 2021 05:38AM EDT

Idorsia Initiates the Phase 3 Registration Study With Selatogrel Using Antares' Autoinjector for the Treatment of Acute Myocardial Infarction

Idorsia Ltd (SIX: IDIA) today announced the initiation of the Phase 3 registration study "SOS-AMI" to evaluate the efficacy and safety of self-administered subcutaneous selatogrel, Idorsia's P2Y12 receptor antagonist, in suspected acute myocardial infarction (AMI).

An AMI, or heart attack, is a life-threatening condition that occurs when blood flow to the heart muscle (myocardium) is suddenly decreased or completely cut off by a blood clot in one or more of the coronary vessels. An AMI requires immediate treatment, as any delay in intervention can result in irreversible damage to the heart muscle and adverse clinical outcomes. According to the US Centers for Disease Control and Prevention, each year more than 800,000 persons living in the US will suffer a heart attack.[1]

Although the management of AMI has improved in recent decades, morbidity and mortality associated with AMI remain high. The majority of deaths occur outside the hospital.[2,3] Early action is crucial for survival and to preserve heart muscle.

Besides aspirin, there are no treatment options currently available for the critical time from onset of AMI symptoms to first medical contact. The development of selatogrel in an autoinjector aims to fulfill this medical gap: upon symptoms suggestive of a heart attack, patients would self-inject selatogrel as early as possible and immediately call for emergency medical help.

Martine Clozel, MD and Chief Scientific Officer at Idorsia, commented:

"From the moment that symptoms start, the clock is ticking. Thrombus formation is progressing, and ischemia is rapidly causing irreversible damage to the heart. In the initial stages of thrombus formation, platelet aggregation dominates a process in which the platelet P2Y12 receptor plays a key role. If left untreated, the thrombus will become fibrin rich, at which point platelets have a more limited role in thrombus formation. This suggests that a fast-acting P2Y12 receptor antagonist could cut short the thrombus formation in the initial stages of thrombus formation. Our drug discovery team has created a compound with unique properties which might fill this important therapeutic gap."

Dr Deepak L. Bhatt, MD, MPH, Executive Director of Interventional Cardiovascular Programs at Brigham and Women's Hospital, Professor of Medicine at Harvard Medical School, and Chair of the Steering Committee for SOS-AMI, commented:

"P2Y12 receptor antagonists have been used in the treatment of millions of patients globally, and their safety and efficacy profiles are well established. Despite the success of chronic treatment with this class and other effective interventions, patients are still suffering recurrent heart attacks. The idea for patients to self-inject early in the onset of symptoms is truly innovative. The subcutaneous route of administration could overcome the onset delay observed with oral compounds from the same class."

To be effective, any antithrombotic treatment for use at the onset of AMI symptoms should be rapidly absorbed and potent, acting quickly to inhibit thrombus formation at an early stage. Inhibition should be reversed after a few hours to avoid interfering with later patient management decisions. It must also have an appropriate safety profile for use prior to formal diagnosis of AMI. Selatogrel has the potential to satisfy these necessary conditions.

Selatogrel administered subcutaneously is a potent, highly selective, fast-acting, reversible P2Y12 receptor antagonist. Two published Phase 2 studies, one in patients with chronic coronary syndromes and one in patients with AMI showed fast and reversible inhibition of platelet aggregation. Subcutaneous administration of selatogrel 16 mg has demonstrated a rapid onset of action, within 15 minutes, with the magnitude of the effect extending over approximately eight hours. Selatogrel was safe and well tolerated in both studies.[6,7]

About the Antares Pharma integrated drug delivery device

In late 2019, Idorsia entered into a global development agreement with Antares Pharma, a US-based leader in autoinjector and rescue pen technologies, to design and customize an autoinjector for selatogrel. The Antares autoinjector was selected for its robustness, reliability, ease-of-use and emergency-ready capabilities key characteristics necessary due to the nature of AMI. Idorsia has confirmed the usability of the Antares auto