Milestone Pharmaceuticals (NASDAQ:MIST) said its first quarter of 2026 marked the beginning of commercial sales for CARDEMYST, its newly approved treatment for acute episodes of paroxysmal supraventricular tachycardia, or PSVT, while the company also moved ahead with a Phase 3 program in atrial fibrillation with rapid ventricular rate.
President and Chief Executive Officer Joseph Oliveto called the period the company’s “first-ever quarter, or more accurately, partial quarter of sales” following the commercial launch of CARDEMYST, the brand name for etripamil. The FDA approved CARDEMYST on Dec. 12 as the first rapid-acting, self-administered prescription therapy for acute PSVT episodes in adults, according to the company.
Early CARDEMYST launch metrics show prescription growth
Chief Commercial Officer Lorenz Muller said Milestone recorded approximately 600 total prescriptions for CARDEMYST through the end of April. That included about 100 prescriptions in February, around 200 in March and approximately 300 in April.
Muller said the February and March totals represented about 300 prescriptions in the company’s first partial quarter of launch, while April alone matched the total from the prior two months combined. He said those prescriptions were written by more than 400 unique healthcare professionals for about 560 unique patients.
“While it’s too early to forecast trends definitively, we are pleased to see data showing steady month-over-month growth,” Muller said.
Management said early prescriber adoption has been broad rather than concentrated among a narrow set of early adopters. In response to an analyst question, Oliveto said about 50% of prescriptions to date had been written by cardiology, about 25% by electrophysiology and the remainder by nurse practitioners, physician assistants, a small number of primary care physicians and other categories not classified in the company’s data.
Muller said Milestone expects clinical and interventional cardiologists to account for a larger share of prescriptions over time. Electrophysiologists may be more likely to use CARDEMYST as a bridge to ablation, he said, while advanced practice providers could become more involved in day-to-day patient management as cardiology practices gain comfort with the drug.
Express Scripts formulary coverage seen as key early payer win
Milestone highlighted the March 31 addition of CARDEMYST to Express Scripts’ commercial national formularies as an early coverage milestone. Muller said the decision gives the product coverage for an estimated 25% of commercially insured patients.
He described the coverage as largely “quality coverage,” meaning patients are more likely to be approved at the point of sale and face less onerous prior authorization requirements. Muller said Milestone is negotiating with other major pharmacy benefit managers and health plans and expects further announcements as discussions progress.
Oliveto said coverage could help both with prescription pull-through at pharmacies and physician willingness to prescribe, because clinicians are sensitive to the administrative burden of prior authorizations and medical exceptions.
During the question-and-answer session, Muller said the company does not provide free drug “right out of the gate.” Instead, it seeks to ensure that payers see demand for the product, with assistance used primarily when prior authorization or medical exception requests are not granted. He agreed with an analyst’s characterization that the approach is more of a bridging program than a sampling effort.
Patient and physician feedback described as positive
Oliveto said cardiology healthcare providers, including physicians, nurses, nurse practitioners and physician assistants, have responded positively to CARDEMYST. He said providers appear to understand the value of the therapy based on its safety profile and self-administration.
Milestone also said it has received positive initial feedback from patients, including some who have used CARDEMYST during an episode and others who reported feeling more prepared simply by having obtained the drug. The company said these insights came from patient engagement, social media monitoring and unsolicited feedback relayed through physicians and nurses.
Muller said many prescriptions have come from physicians after only one or two sales representative interactions, which management views as a positive early signal. He said the company has engaged with about one-third of its roughly 10,000 target physicians and is seeing a prescribing rate north of 10% among reached physicians.
Phase 3 AFib RVR trial begins
Milestone also said it has initiated ReVeRA-301, a Phase 3 pivotal trial of etripamil in patients with atrial fibrillation and rapid ventricular rate, or AFib RVR.
Oliveto said the trial is based on a Phase 2 study in which patients receiving etripamil demonstrated a statistically significant and clinically meaningful reduction in ventricular rate compared with placebo and showed symptomatic improvement.
ReVeRA-301 is designed as a double-blind, placebo-controlled, event-driven study in which patients self-administer the drug outside the healthcare setting. The trial uses the same 70-milligram dose and repeat-dose regimen approved for CARDEMYST in PSVT.
Oliveto said Milestone is labeling clinical study drug, has begun contracting with sites and has posted the trial on clinicaltrials.gov. The company expects to enroll the first patient in the second half of 2026.
In response to a question, Oliveto said the study is expected to require about 150 to 200 total AFib RVR events and could enroll up to 600 patients across multiple countries and sites. He estimated the trial would take about two years from first patient enrolled to data, though he noted that timing depends on multiple variables.
Milestone reports $184 million cash balance
Chief Financial Officer Amit Hasija reported that Milestone had approximately $184 million in cash, cash equivalents and short-term investments as of March 31, compared with $106 million at the end of 2025. He said the cash balance is expected to support CARDEMYST launch activities and operations into the second half of 2027, including execution of ReVeRA-301.
- Product revenue: $0.2 million in the first quarter of 2026.
- R&D expense: $3.3 million, net of tax credits, compared with $5 million in the year-earlier quarter.
- G&A expense: $4.8 million, compared with $5.2 million a year earlier.
- Commercial expense: $15.8 million, compared with $10.4 million, reflecting additional costs tied to the CARDEMYST launch.
- Net loss: $26.1 million, or $0.20 per share, compared with $20.8 million, or $0.31 per share, in the first quarter of 2025.
Hasija said the higher cash balance primarily reflected a $75 million cash payment received in January under Milestone’s royalty purchase agreement with RTW, as well as about $19 million in net proceeds from at-the-market sales and Series A warrant exercises during the quarter. Operating cash burn in the quarter was approximately $23.7 million.
Oliveto said Milestone’s priorities for the rest of 2026 include disciplined launch execution, expanding payer access, advancing clinical development and managing resources responsibly.
About Milestone Pharmaceuticals (NASDAQ:MIST)
Milestone Pharmaceuticals, Inc is a clinical-stage biopharmaceutical company focused on developing innovative therapies for respiratory diseases. The company’s research emphasizes both biologic and small-molecule approaches designed to improve mucociliary clearance, reduce airway inflammation and address chronic and refractory cough. Milestone’s pipeline targets key underserved conditions such as cystic fibrosis, primary ciliary dyskinesia and severe asthma.
Milestone’s lead product candidates are delivered through inhalation or systemic administration, reflecting the company’s commitment to optimizing therapeutic delivery directly to the lungs.
