Alnylam Reports Positive KARDIA-2 Topline Study Results Demonstrating Clinically Significant Blood Pressure Reductions When Zilebesiran is Added to Standard of Care Antihypertensives

– Study Met the Primary Endpoint Demonstrating Clinically Significant Systolic Blood Pressure Reductions at Month 3 When Zilebesiran Was Added to a Diuretic, Calcium-Channel Blocker or Angiotensin Receptor Blocker –

– Zilebesiran Demonstrated an Encouraging Safety and Tolerability Profile When Added to Standard of Care Antihypertensives –

– Study Results Support Potential for Biannual Dosing of Zilebesiran –

– Full Study Results to Be Presented as a Late-Breaking Clinical Trial at the 2024 American College of Cardiology Annual Scientific Session on April 7 –

– Alnylam and Roche Also Announce Initiation of the KARDIA-3 Phase 2 Study in Patients at High Cardiovascular Risk with Uncontrolled Hypertension Despite Standard of Care Antihypertensive Treatments –

CAMBRIDGE, Mass.–(BUSINESS WIRE)–Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), the leading RNAi therapeutics company, today announced that the KARDIA-2 Phase 2 study of zilebesiran, an investigational RNAi therapeutic targeting liver-expressed angiotensinogen (AGT) in development for the treatment of hypertension, met the primary endpoint showing that zilebesiran resulted in clinically and statistically significant additive, placebo-adjusted reductions in 24-hour mean systolic blood pressure (SBP) at Month 3 as measured by ambulatory blood pressure monitoring (ABPM) in each of three independent patient cohorts receiving the standardized background therapies of either a thiazide-like diuretic (indapamide), calcium channel blocker (amlodipine) or angiotensin receptor blocker (olmesartan). Zilebesiran demonstrated an encouraging safety and tolerability profile when added to these standard of care antihypertensives. The Company believes these findings support further development.

“We are thrilled that a single dose of zilebesiran achieved clinically significant, additional reductions in systolic blood pressure when administered to patients who are not adequately controlled with commonly prescribed antihypertensives,” said Simon Fox, Ph.D., Vice President, Zilebesiran Program Lead at Alnylam. “These KARDIA-2 results, showing durable additional levels of blood pressure reduction on top of what is achieved by standard of care first-line antihypertensives with an encouraging safety profile, reinforce our confidence in zilebesiran’s differentiated profile. We look forward to sharing the full KARDIA-2 data as a late-breaking clinical trial at the upcoming American College of Cardiology Annual Scientific Session.”

The KARDIA-2 Phase 2 study is a randomized, double-blind (DB), placebo-controlled study designed to evaluate the efficacy and safety of zilebesiran, when added to standard of care antihypertensive medications, in adults with mild-to-moderate hypertension. This global, multicenter study enrolled 672 adults with hypertension. Patients who met all inclusion criteria and none of the exclusion criteria during a screening period were first randomized into three different cohorts to receive open-label therapy with olmesartan, amlodipine or indapamide as their protocol-specified background antihypertensive medication during a run-in period of at least four weeks. Following the run-in period, eligible patients were randomized 1:1 to receive 600 mg zilebesiran or placebo in addition to their protocol-specified background antihypertensive medication for six months.

The primary endpoint is the change from baseline in mean SBP at Month 3, assessed by 24-hour ABPM. Additional endpoints include the change in 24-hour mean SBP after six months of treatment assessed by ABPM, change in office SBP at Month 3 and Month 6, and change in diastolic blood pressure (DBP) measured by ABPM and office blood pressure at Month 3 and Month 6. Safety will be assessed throughout the study.

Alnylam and Roche today also announced the initiation of the global KARDIA-3 (NCT06272487) Phase 2 study, a randomized, DB, placebo-controlled, multicenter study designed to evaluate the efficacy and safety of zilebesiran used as an add-on therapy in adult patients with high cardiovascular risk and uncontrolled hypertension despite treatment with two to four standard of care antihypertensive medications. Patients with estimated glomerular filtration rate (eGFR) ≥45 mL/min/1.73m2 will be enrolled to cohort A, and patients with eGFR 30 to <45 mL/min/1.73m2 will be enrolled to cohort B. Patients who meet all of the inclusion and none of the exclusion criteria after the screening period will be randomized to receive 300 or 600 mg zilebesiran or placebo in cohort A on day 1, or 150, 300, or 600 mg zilebesiran or placebo in cohort B on day 1, of a 6-month DB treatment period as add-on therapy to their background antihypertensive medications. After the 6-month DB treatment period, patients will enter the 6-month safety follow-up period.

The primary endpoint is the change from baseline at Month 3 in mean seated office SBP. Additional endpoints include change from baseline at Month 3 in 24-hour mean SBP assessed by ABPM, change from baseline at Month 6 in mean seated office SBP and in 24-hour mean SBP assessed by ABPM. Safety will be assessed throughout the study.

About Zilebesiran

Zilebesiran is an investigational, subcutaneously administered RNAi therapeutic targeting angiotensinogen (AGT) in development for the treatment of hypertension in high unmet need populations. AGT is the most upstream precursor in the Renin-Angiotensin-Aldosterone System (RAAS), a cascade which has a demonstrated role in blood pressure (BP) regulation and its inhibition has well-established anti-hypertensive effects. Zilebesiran inhibits the synthesis of AGT in the liver, potentially leading to durable reductions in AGT protein and ultimately, in the vasoconstrictor angiotensin (Ang) II. Zilebesiran utilizes Alnylam’s Enhanced Stabilization Chemistry Plus (ESC+) GalNAc-conjugate technology, which enables infrequent subcutaneous dosing with increased selectivity and the potential to achieve tonic blood pressure control demonstrating consistent and durable blood pressure reduction throughout a 24-hour period, sustained up to six months after a single dose of zilebesiran. The safety and efficacy of zilebesiran have not been established or evaluated by the FDA, EMA or any other health authority. Zilebesiran is being co-developed and co-commercialized by Alnylam and Roche.

About Hypertension

Uncontrolled hypertension is the chronic elevation of blood pressure (BP), defined by the 2017 ACC/AHA guidelines as ≥130 mmHg systolic blood pressure (SBP) and ≥80 mmHg diastolic blood pressure (DBP). More than one billion people worldwide live with hypertension.ⁱ Approximately one in three adults are living with hypertension worldwide, with up to 80% of individuals remaining uncontrolled despite the availability of several classes of oral anti-hypertensive treatments. Despite the availability of anti-hypertensive medications, there remains a significant unmet medical need, especially given the poor rates of adherence to existing daily oral medications, resulting in inconsistent BP control and an increased risk for stroke, heart attack and premature death.ⁱⁱ In particular, there are a number of high unmet need settings where novel approaches to hypertension warrant additional development focus, including patients with poor medication adherence and in patients with high cardiovascular risk.

About RNAi

RNAi (RNA interference) is a natural cellular process of gene silencing that represents one of the most promising and rapidly advancing frontiers in biology and drug development today. Its discovery has been heralded as “a major scientific breakthrough that happens once every decade or so,” and was recognized with the award of the 2006 Nobel Prize for Physiology or Medicine. By harnessing the natural biological process of RNAi occurring in our cells, a new class of medicines known as RNAi therapeutics is now a reality. Small interfering RNA (siRNA), the molecules that mediate RNAi and comprise Alnylam’s RNAi therapeutic platform, function upstream of today’s medicines by potently silencing messenger RNA (mRNA) – the genetic precursors that encode for disease-causing or disease pathway proteins – thus preventing them from being made. This is a revolutionary approach with the potential to transform the care of patients with genetic and other diseases.

About Alnylam Pharmaceuticals

Alnylam Pharmaceuticals (Nasdaq: ALNY) has led the translation of RNA interference (RNAi) into a whole new class of innovative medicines with the potential to transform the lives of people afflicted with rare and prevalent diseases with unmet need. Based on Nobel Prize-winning science, RNAi therapeutics represent a powerful, clinically validated approach yielding transformative medicines. Since its founding in 2002, Alnylam has led the RNAi Revolution and continues to deliver on a bold vision to turn scientific possibility into reality. Alnylam’s commercial RNAi therapeutic products are ONPATTRO^® (patisiran), AMVUTTRA^® (vutrisiran), GIVLAARI^® (givosiran), OXLUMO^® (lumasiran), and Leqvio^® (inclisiran), which is being developed and commercialized by Alnylam’s partner, Novartis. Alnylam has a deep pipeline of investigational medicines, including multiple product candidates that are in late-stage development. Alnylam is executing on its “Alnylam P⁵x25” strategy to deliver transformative medicines in both rare and common diseases benefiting patients around the world through sustainable innovation and exceptional financial performance, resulting in a leading biotech profile. Alnylam is headquartered in Cambridge, MA. For more information about our people, science and pipeline, please visit www.alnylam.com and engage with us on X (formerly Twitter) at @Alnylam, or on LinkedIn, Facebook, or Instagram.

Alnylam Forward Looking Statements

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. All statements other than historical statements of fact regarding Alnylam’s expectations, beliefs, goals, plans or prospects including, without limitation, Alnylam’s views with respect to the results of the KARDIA-2 Phase 2 study of zilebesiran or the enrollment or conduct of the KARDIA-3 Phase 2 study, Alnylam’s views with respect to the potential role for zilebesiran as a novel, subcutaneously administered gene silencing approach to hypertension, its views that zilebesiran has the potential to be an effective and highly-differentiated treatment; its expectations regarding its aspiration to become a leading biotech company and the planned achievement of its “Alnylam P⁵x25” strategy, should be considered forward-looking statements. Actual results and future plans may differ materially from those indicated by these forward-looking statements as a result of various important risks, uncertainties and other factors, including, without limitation, risks and uncertainties relating to: Alnylam’s ability to successfully execute on its “Alnylam P⁵x25” strategy; Alnylam’s ability to discover and develop novel drug candidates and delivery approaches and successfully demonstrate the efficacy and safety of its product candidates; the pre-clinical and clinical results for Alnylam’s product candidates, including vutrisiran, zilebesiran, and ALN-APP; actions or advice of regulatory agencies and Alnylam’s ability to obtain and maintain regulatory approval for its product candidates, including vutrisiran, as well as favorable pricing and reimbursement; successfully launching, marketing and selling Alnylam’s approved products globally; delays, interruptions or failures in the manufacture and supply of Alnylam’s product candidates or its marketed products; obtaining, maintaining and protecting intellectual property; Alnylam’s ability to successfully expand the approved indications for AMVUTTRA in the future; Alnylam’s ability to manage its growth and operating expenses through disciplined investment in operations and its ability to achieve a self-sustainable financial profile in the future without the need for future equity financing; the direct or indirect impact of the COVID-19 global pandemic or any future pandemic on Alnylam’s business, results of operations and financial condition; Alnylam’s ability to maintain strategic business collaborations; Alnylam’s dependence on third parties for the development and commercialization of certain products, including Roche, Novartis, Sanofi, Regeneron and Vir; the outcome of litigation; the risk of future government investigations; and unexpected expenditures; as well as those risks more fully discussed in the “Risk Factors” filed with Alnylam’s 2023 Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC), as may be updated from time to time in Alnylam’s subsequent Quarterly Reports on Form 10-Q and in its other SEC filings. In addition, any forward-looking statements represent Alnylam’s views only as of today and should not be relied upon as representing its views as of any subsequent date. Alnylam explicitly disclaims any obligation, except to the extent required by law, to update any forward-looking statements.

ⁱ Hypertension. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/hypertension. Published September 2019. Accessed November 2021.

ⁱⁱ Carey, R. M., Muntner, P., Bosworth, H. B., & Whelton, P. K. (2018). Prevention and Control of Hypertension: JACC Health Promotion Series. Journal of the American College of Cardiology, 72(11), 1278–1293.

Contacts

Alnylam Pharmaceuticals, Inc.

Christine Regan Lindenboom

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+1-617-682-4340

Josh Brodsky

(Investors)

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