Newsletter
Published: 2 Sep 2025, 11:52 IST — Updated: 6 Sep 2025, 12:11 IST

– Alnylam starts Phase 3 trial for zilebesiran in 2023.
– Mid-stage study showed zilebesiran failed to meet blood pressure goals.

Alnylam Pharmaceuticals initiates a Phase 3 trial for zilebesiran, despite a mid-stage study setback. The trial, named KARDIA-3, aims to evaluate the cardiovascular outcomes of the hypertension therapy. This decision follows data indicating that zilebesiran did not meet its primary endpoint in a Phase 2 study focused on blood pressure reduction.

The KARDIA-3 trial will enroll approximately 1,500 participants globally. It will assess the impact of zilebesiran on major adverse cardiovascular events (MACE) over a period of several years. The trial’s primary endpoint is the reduction in MACE, which includes heart attack, stroke, and cardiovascular death. Alnylam plans to conduct this trial across multiple countries, with results expected to provide insights into the drug’s efficacy beyond blood pressure control.

Despite the mid-stage failure, Alnylam remains committed to exploring zilebesiran’s potential benefits. The company believes that the drug’s mechanism of action could offer advantages in reducing cardiovascular events. Zilebesiran is an RNA interference (RNAi) therapeutic designed to inhibit angiotensinogen, a key protein involved in blood pressure regulation.

The decision to proceed with the Phase 3 trial underscores Alnylam’s confidence in zilebesiran’s broader therapeutic potential. The company aims to address unmet needs in hypertension management, particularly for patients at high risk of cardiovascular events. This trial could significantly impact the treatment landscape if successful.

For more information on Alnylam’s clinical trials, visit their official website. To learn more about ongoing clinical trials, explore our dedicated section.