Milestone Pharmaceuticals has raised $55 million to take a cardiovascular disease asset through phase 3. The series C tees Milestone up to test its intranasal calcium channel blocker etripamil in patients with paroxysmal supraventricular tachycardia (PSVT).
Novo Holdings A/S led the round with the support of new investors Forbion Capital Partners and Tekla Capital Management. Domain Associates, Fonds de solidarité FTQ, BDC Capital and other investors that helped Milestone raise $30 million across its series A and B rounds also returned to bankroll Milestone’s advance into a pivotal trial.
Montreal, Canada-based Milestone will use the money to take etripamil, also known as MSP-2017, through a phase 3 program made up of pivotal and supportive trials while laying the groundwork for commercialization of the drug.
Etripamil is designed to quickly stop episodes of PSVT, which are characterized by the abrupt onset of a rapid heart rate. The prognosis for patients with most forms of PSVT who don’t have structural heart disease is good. But Milestone thinks the effect of the condition on a patient’s quality of life means there is a market for a self-administered drug that quickly stops episodes.
Milestone’s belief that etripamil is such a drug is backed up by phase 2 data. The study enrolled 104 patients with PSVT who were awaiting ablation—the current go-to treatment for persistent PSVT—and were free from other clinically-significant cardiovascular conditions. These patients were randomized to receive one of four doses of etripamil or placebo. Investigators then recorded how many patients converted to sinus rhythm within 15 minutes of receiving the drug.
The three highest doses of etripamil outperformed placebo against this yardstick, with between 75% and 95% of patients converting as compared to 35% in the placebo arm. That suggested the drug terminates PSVT. The data also pointed to 70 mg as the optimum dose as participants who received the two higher doses experienced transient drops in blood pressure.
As etripamil goes deeper into development and potentially onto the market Milestone will need to show it has a safety profile conducive to home use. Close to half of patients on etripamil in the phase 2 experienced nasal congestion. Milestone will also need to show etripamil can find a place among the established treatment options for PSVT, such as ablation.
Responsibility for guiding etripamil through a phase 3 program capable of starting to answer these questions will fall on Joseph Oliveto, who took over as CEO in March. Oliveto landed at Milestone after guiding Chelsea Therapeutics through a tricky patch following the FDA’s rejection of hypotension drug Northera. Chelsea went on to win approval for Northera before selling up to Lundbeck in a $658 million deal.