This year’s European Society of Cardiology (ESC) Congress showed just how quickly cardiology is changing. Late-breaking trials, new scientific data and major guideline updates all pointed to a field that is becoming both more crowded and more complex.
A central question the conference sought to address was how effectively the two main types of ATTR-CM treatment work. Stabilizers are designed to prevent the transthyretin protein from breaking apart, while silencers reduce its production. The debate centered on whether silencers offer enough additional benefit over established stabilizers in this significant rare disease market.
One of the clearest lessons was that the challenge is no longer simply bringing more treatments to market. It is increasingly about finding the right patients earlier, understanding how different therapies compare and deciding where each option fits as standards of care improve. ATTR-CM was one of the strongest examples of that shift, with the conference data sharpening the debate over whether silencers offer enough additional benefit over established stabilizers. The same pattern could also be seen in new guidelines and in the growing role of digital monitoring.
Alnylam ($ALNY) Faces New Questions Over Amvuttra in ATTR-CM
Alnylam Pharmaceuticals came to ESC looking to strengthen the case for Amvuttra in ATTR-CM, but the data arguably leave some important questions unanswered. While the drug is already approved, the estimated benefit appeared more modest than many investors and clinicians may have hoped, particularly given the growing expectation that newer therapies will need to demonstrate clear advantages over established treatments. The key question is whether ATTR-CM silencer treatments offer enough additional benefit on top of stabilizers that are already delivering meaningful clinical outcomes.
In light of this, there remains uncertainty around the extent of Amvuttra’s value and whether it will be sufficient to secure a strong position in an increasingly competitive market. The FDA’s decision earlier this year to challenge Alnylam’s survival claims based on an open-label extension of HELIOS-B only adds to the need for caution. It is, therefore, perhaps unsurprising that Alnylam’s share price has come under pressure and that questions are being raised about the long-term commercial viability of Amvuttra in ATTR-CM.
Rather than definitively strengthening the case for Amvuttra, Alnylam’s participation at ESC suggests that important questions remain about the true scale of its advantage and whether the evidence is sufficient to establish a clear benefit over existing treatments.
AstraZeneca ($AZN) Casts Further Doubt on Silencers in ATTR-CM
In perhaps a similar spirit, AstraZeneca and Ionis used ESC to revisit the results of the Phase 3 CARDIO-TTRansform trial of Wainua (eplontersen), another potential treatment for ATTR-CM. They faced a somewhat different challenge, however, as the trial had already failed its primary endpoint, with Wainua unable to significantly reduce cardiovascular mortality and recurrent cardiovascular events in the overall study population.
The companies sought to contextualize the findings, but the presentation arguably highlighted one of the trial’s central challenges. If the apparent benefit is less clear among patients already receiving stabilizer therapy, the data raise broader questions about how much additional value silencers can deliver beyond treatments that are already producing meaningful clinical outcomes. The broader question, however, is what this means for an ATTR-CM market that is becoming increasingly competitive. As new treatments emerge, should attention shift towards newer therapies, or remain focused on established stabilizers that may already be providing much of the available benefit?
New ESC Guidelines and Huawei Point to a Prevention First Approach
ESC also saw the release of new guidelines that could change how cardiovascular patients are identified and managed. The updated heart failure guidance simplifies how patients are classified and puts more focus on prevention and earlier intervention. In practice, that means clinicians may be looking for risk earlier and across a broader group of patients, rather than waiting until disease is more advanced.
That change is creating more room for digital tools. Huawei used ESC to preview its Watch D3, a wrist-based ambulatory blood pressure monitor designed to track blood pressure in everyday settings. It is one example of how wearables are moving beyond basic wellness tracking and towards data that could help identify risk earlier, monitor patients more closely and support treatment decisions.
Reflecting on ESC 2026, ATTR-CM emerged as a key area of focus. The AstraZeneca and Alnylam data raised questions about whether silencers can offer enough benefit over established stabilizers, while new guidelines and digital tools highlighted the importance of identifying risk earlier and monitoring patients more closely. The key question now, arguably, is which approaches can genuinely improve on what is already available, and which patients are most likely to benefit.
