Roche partnered with Alnylam to co-develop and co-commercialize zilebesiran, an RNAi therapeutic for hypertension in high cardiovascular risk patients, with Roche paying 60% of development costs. The program advanced into the global Phase 3 ZENITH cardiovascular outcomes trial (~11,000 patients, 35 countries); first-patient dosing on Oct 1, 2025 triggered a $300M milestone payment from Roche — the first major milestone realized under the agreement.