8-K: Boston Scientific posts wins in PE and AF trials

Boston Scientific reported NEJM-published, ACC.26 late-breaker data showing EKOS superiority in pulmonary embolism and WATCHMAN FLX non-inferior efficacy with superior bleeding outcomes vs NOACs in atrial fibrillation.

Summary

• Announced two pivotal clinical updates: HI-PEITHO (EKOS for intermediate-risk pulmonary embolism) and CHAMPION-AF (WATCHMAN FLX vs NOACs in non-valvular atrial fibrillation).
• HI-PEITHO met its composite primary endpoint, with EKOS plus anticoagulation superior to anticoagulation alone (4.0% vs 10.3%; P=0.005), a 61% relative reduction in events within 7 days.
• HI-PEITHO showed lower cardiorespiratory decompensation/collapse with EKOS (3.7% vs 10.3%) and no intracranial bleeding through 30 days; 544 patients across 59 U.S./EU sites; follow-up planned to 1 year.
• CHAMPION-AF (n=3,000; 141 global sites) met all primary and secondary endpoints at 36 months: non-procedural bleeding was statistically lower with WATCHMAN FLX vs NOACs (10.9% vs 19.0%; P<0.001), a 45% relative reduction.
• Including procedural bleeding, WATCHMAN FLX still had significantly lower major/clinically relevant non-major bleeding (12.8% vs 19.0%; P<0.001), a 34% relative reduction.
• Primary efficacy endpoint (stroke, cardiovascular or unexplained death, or systemic embolism) was non-inferior for WATCHMAN FLX vs NOACs (5.7% vs 4.8%; P<0.001 for non-inferiority).
• Secondary safety endpoint was non-inferior for major bleeding (procedural and non-procedural) at 36 months (5.9% vs 6.4%; P<0.001).
• A combined safety/efficacy endpoint favored WATCHMAN FLX (15.1% vs 21.8%; P<0.001), with a 99% procedural success rate; follow-up will continue to 5 years.
• Company plans to use CHAMPION-AF data in submissions to expand indication and coverage; both trials were presented as ACC.26 late-breakers and published in NEJM.

Sentiment

Score: 8

Explanation: StockSavvy.ai views this as a strongly positive clinical inflection, with NEJM-validated, late-breaking data that can expand addressable markets and support guideline and coverage gains, albeit without immediate financial quantification.

Positives

• EKOS plus anticoagulation was superior to anticoagulation alone in intermediate-risk PE (4.0% vs 10.3%; P=0.005), a 61% relative reduction in primary endpoint events.
• EKOS reduced cardiorespiratory decompensation/collapse (3.7% vs 10.3%) with no intracranial bleeding through 30 days.
• CHAMPION-AF met all primary and secondary endpoints; WATCHMAN FLX reduced non-procedural bleeding vs NOACs (10.9% vs 19.0%; P<0.001), a 45% relative reduction.
• Including procedural bleeding, WATCHMAN FLX still showed significantly less bleeding (12.8% vs 19.0%; P<0.001), a 34% relative reduction.
• WATCHMAN FLX achieved non-inferior efficacy vs NOACs for stroke/CV death/systemic embolism (5.7% vs 4.8%; P<0.001), and delivered net clinical benefit superiority on a composite endpoint (15.1% vs 21.8%; P<0.001).
• High procedural success in CHAMPION-AF (99%), supporting device reliability.
• NEJM publications and ACC.26 late-breakers enhance credibility and guideline influence potential.
• Company intends to pursue expanded indications and coverage for WATCHMAN FLX, signaling possible market expansion.

Negatives

• CHAMPION-AF primary efficacy was non-inferior, not superior, to NOACs (5.7% vs 4.8%).
• HI-PEITHO primary endpoint assessed within 7 days; longer-term outcomes are pending 1-year follow-up.
• No revenue, margin, or adoption projections were provided; commercial impact not quantified.

Risks

• Economic conditions and foreign currency fluctuations may affect performance.
• Future U.S. and global political, competitive, reimbursement and regulatory conditions, including changing trade and tariff policies, could impact outcomes.
• Geopolitical events, conflicts and tensions may disrupt operations.
• Manufacturing, distribution and supply chain disruptions and cost increases pose risks.
• Cybersecurity events could cause operational disruptions.
• Public health emergencies or extreme weather/climate-related events may disrupt business.
• Labor shortages and increased labor costs could affect execution.
• Variations in outcomes of ongoing and future clinical trials and market studies could alter expectations.
• New product introductions by competitors and changes in expected procedural volumes may impact growth.
• Acquisition closing and integration risks could affect strategy.
• Intellectual property and litigation risks remain ongoing concerns.
• Financial market conditions and execution of cost-savings/growth initiatives may vary from plans.
• Future business decisions by the company and competitors could change competitive dynamics.

Future Outlook

Management plans to use CHAMPION-AF results to submit for expanded indications and coverage for WATCHMAN FLX as a first-line stroke risk reduction option, while HI-PEITHO results may support consideration of EKOS plus anticoagulation as first-line therapy in intermediate-risk PE; ongoing patient follow-up (HI-PEITHO to 1 year; CHAMPION-AF to 5 years) and potential guideline updates could further drive adoption, subject to regulatory and reimbursement decisions.

Management Comments

• Principal investigator Dr. Stavros Konstantinides stated EKOS therapy showed clinical efficacy without increased major bleeding and with shorter hospital stays vs anticoagulation alone.
• Dr. Michael R. Jaff, VP and CMO, Vascular Therapies, said HI-PEITHO provides robust randomized data to inform treatment decisions and supports considering EKOS plus anticoagulation as first-line therapy.
• Study co-chair Dr. Martin Leon called CHAMPION-AF a meaningful milestone that could transform stroke risk reduction treatment and position WATCHMAN FLX as a first-line option.
• Dr. Brad Sutton, CMO, Atrial Fibrillation Solutions, said the CHAMPION-AF data will be used to expand indication and coverage for WATCHMAN and highlighted non-adherence to blood thinners (about 40%) as a need for a one-time implant solution.

Industry Context

StockSavvy.ai notes that randomized, NEJM-published superiority of EKOS over anticoagulation in intermediate-risk PE is a significant differentiator versus competitors in mechanical thrombectomy and catheter-directed therapies, where high-quality RCT evidence has been limited. In AF stroke prevention, CHAMPION-AF’s non-inferior efficacy to NOACs with superior bleeding outcomes and strong procedural success positions WATCHMAN FLX favorably against pharmacologic therapy and rival LAAC devices (e.g., Abbott’s Amulet), supporting potential guideline and coverage expansion and accelerating category growth.

Comparison to Industry Standards

• AF stroke prevention: Compared to standard NOAC therapy, WATCHMAN FLX achieved non-inferior efficacy (5.7% vs 4.8%) and superior bleeding outcomes (10.9% vs 19.0% non-procedural bleeding), aligning with and extending prior evidence that LAAC can match pharmacologic stroke prevention while improving bleeding profiles; this strengthens competitive positioning versus Abbott’s Amulet system and prior mixed-device LAAC studies (e.g., PRAGUE-17), with a best-in-class 99% procedural success rate.
• Pulmonary embolism: EKOS demonstrated randomized superiority over anticoagulation alone (4.0% vs 10.3% composite at 7 days) with no intracranial hemorrhage through 30 days, a high evidentiary bar compared with many competitors relying on registries or non-randomized data (e.g., mechanical thrombectomy from Inari and Penumbra). The RCT framework and NEJM publication elevate EKOS within interventional PE care standards.

Related Party Transactions

• Dr. Stavros Konstantinides is a paid consultant of Boston Scientific Corporation (not compensated for the press release).
• Dr. Martin Leon is a paid consultant of Boston Scientific Corporation (not compensated for the press release).

Stakeholder Impact

• Patients: Potential for lower bleeding risk and durable stroke protection with WATCHMAN FLX; improved short-term outcomes in intermediate-risk PE with EKOS.
• Physicians: Robust randomized data to guide first-line therapy decisions in AF stroke prevention and PE intervention.
• Hospitals: Potential for shorter hospital stays with EKOS and streamlined AF care pathways with a one-time implant.
• Payers: Evidence base to support expanded coverage decisions for WATCHMAN FLX; potential cost offsets from reduced bleeding and admissions.
• Shareholders: Positive pivotal results in two large cardiovascular markets signal potential acceleration in adoption and revenue growth, subject to regulatory and reimbursement outcomes.

Next Steps

• Use CHAMPION-AF results in submissions to expand indication and coverage for WATCHMAN FLX as a first-line option.
• Continue CHAMPION-AF patient follow-up through five years with additional endpoints.
• Continue HI-PEITHO patient follow-up to one year.
• Engage clinicians and societies as data may support guideline updates and broader first-line consideration for EKOS and WATCHMAN FLX.

Key Dates

Recommendation

Two NEJM-published, ACC.26 late-breaker trials delivered superiority (EKOS) and non-inferior efficacy with superior bleeding (WATCHMAN FLX), underpinning potential guideline shifts and expanded coverage; while financials aren’t disclosed, the clinical momentum and planned submissions justify a constructive stance.

Keywords

Boston Scientific, EKOS, HI-PEITHO, pulmonary embolism, WATCHMAN FLX, CHAMPION-AF, left atrial appendage closure, NOACs, atrial fibrillation, ultrasound-facilitated thrombolysis, catheter-directed thrombolysis, NEJM, ACC.26, clinical trial, non-inferiority, superiority, stroke prevention, bleeding reduction, cardiovascular devices