Idorsia's P2Y12 receptor antagonist selatogrel has significantly inhibited platelet aggregation in two phase 2 trials. The primary endpoint successes in patients with stable coronary artery disease (CAD) or acute myocardial infarction (AMI) set Idorsia up to plan the initiation of a phase 3 study.
Switzerland’s Idorsia, which spun out of Actelion as part of the Johnson & Johnson acquisition, has designed selatogrel to quickly inhibit platelet aggregation by acting on the P2Y12 receptor. As drugs such as Plavix have shown, targeting P2Y12 can prevent the formation of blood clots and thereby improve cardiovascular outcomes.
More recently, AstraZeneca’s Brilinta has shown that direct-acting, reversibly binding antagonists of P2Y12 can have wider therapeutic windows and superior efficacy than Plavix and its ilk. However, Idorsia thinks there is still a need for P2Y12 antagonists that have a lower risk of bleeding side effects.
To test whether selatogrel can meet that need, Idorsia initiated two phase 2 trials of the drug. One of the trials enrolled 346 patients with stable CAD and gave them one of two doses of selatogrel or placebo. The other trial enrolled 48 patients with confirmed AMI and randomized them to receive one of two doses of selatogrel on top of antithrombotic treatment.
Both of the trials used platelet aggregation following a single subcutaneous injection as their primary endpoint, and both studies met that objective. Upward of 89% of patients in the treatment arms of the trials experienced the predefined extent of platelet aggregation inhibition. Aggregation inhibition was seen within 15 minutes—an important consideration in AMI—and remained at a high level for four to eight hours.
Idorsia is yet to share more efficacy data and has only discussed the safety results in broad terms, stating that no patients suffered treatment-emergent serious bleeds. Further details of the safety data will be important given the propensity for drugs that act on P2Y12 to increase the risk of bleeding.
Researchers at Idorsia are preparing to share more data at an upcoming scientific congress while gearing up for the next stage of development. Idorsia plans to discuss its plans for phase 3 with regulators at the upcoming end of phase 2 meetings.