CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-08-18). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.7.
Verdict No. 2866 · Search date 2026-08-18 · Methodology v0.7

Subcutaneous zilebesiran,
does it really help with Change in 24-hour mean ambulatory systolic blood pressure at month 3 in mild-to-moderate hypertension?

30-Second Summary
C
Evidence Grade C · 50 · Safety caution
Zilebesiran substantially lowered 24-hour systolic blood pressure, but cardiovascular-event reduction has not yet been tested
Over six months, hyperkalemia occurred in 19/302 (6.3%) versus 2/75 (2.7%), hypotension in 13/302 versus 1/75 (1.3%), and injection-site reactions in 19 (6.3%) versus none. Months-long pharmacodynamic activity is both convenient and difficult to reverse during dehydration, bleeding, or infection, requiring blood-pressure, potassium, and kidney monitoring.
What the
research shows
The grade is C with 50 points. KARDIA-1 randomized 394 participants, and 330 had month-3 primary endpoint data. Placebo-adjusted changes in 24-hour mean ambulatory systolic blood pressure at month 3 were -14.1 mm Hg (95% CI -19.2 to -9.0), -16.7 (-21.2 to -12.3), and -15.7 (-20.8 to -10.6) across dose comparisons. The primary endpoint was a blood-pressure surrogate, capping the grade at C.
What the
ads claim
Zilebesiran is not approved in Korea, but Korean news and investment reports already circulate it as a 'once-every-six-months blood-pressure injection.' Verdict 2865 concerns givosiran, another siRNA with a different indication. In the existing corpus, verdict 630 is C with 55 points for inclisiran, verdict 1621 is B with 78 points for vutrisiran, and verdict 2816 is C with 54 points for fitusiran; they address LDL-C, ATTR-CM, and hemophilia bleeding and were not pooled with hypertension.
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Useful facts when choosing a product

  • Zilebesiran is an investigational siRNA that suppresses hepatic angiotensinogen synthesis.
  • Biannual dosing may reduce missed pills, but months-long pharmacodynamic activity can be difficult to reverse during hypotension, volume depletion, bleeding, or infection; the paper noted that RNA-interference reversal agents were being considered.
  • Primary endpoint data were available in 68, 137, and 65 zilebesiran participants across dose comparisons and 60 placebo participants.
  • Korean media describe a twice-yearly injection, but Korean marketing authorization was not identified.
Gap Measurement · Verdict 2866 · C 50
What advertising claims
What independent, higher-quality research supports
△ GAP
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What the research actually shows

· Defect name: Missing primary endpoint data · Listed item: Substantial attrition (≥15%) · Original evidence that the requirement was met: Of 394 randomized participants, 330 had month-3 primary endpoint data ("Primary end point data were available for 68 ... 137 ... 65 ... and 60 patients"), leaving 64 (16.2%) missing. Because the primary endpoint was a continuous measurement at a fixed time point, this is missingness rather than censoring. · Avoidability: Partly avoidable - wartime loss to follow-up was unavoidable, but additional sites and stronger follow-up could have reduced missingness. The trial randomized 394 participants, not below the 200-person small-study threshold; its primary assessment was at three months, not less than 12 weeks; and allocation concealment, masking, and a prespecified primary endpoint were confirmed. Alnylam Pharmaceuticals funded the trial and medical writing, and the sponsor participated in design, conduct, data work, interpretation, and manuscript preparation. Stiglitz, Goyal, Guo, and Zappe were Alnylam employees and stockholders, and several other authors disclosed Alnylam payments or grants.

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Why this is classified as C (50)

The primary endpoint was change in 24-hour ambulatory systolic blood pressure, a surrogate, so the ceiling is C. The large blood-pressure effect is credited, but 16.2% lacked the month-3 primary endpoint and one Alnylam phase 2 trial did not test cardiovascular events, giving C with 50 points.

Counterpoint. The population had mild-to-moderate hypertension after antihypertensive washout. Results cannot automatically be transferred to severe hypertension, intensive multidrug treatment, long-term safety, or event prevention.

Rejudgment record. Cross-check applied — Cross-checked NCT04936035 and the JAMA report for the ambulatory-BP primary endpoint, allocation, masking, analysis, 64/394 (16.2%) missingness, Alnylam sponsorship, and harms

Scoring profile behind this grade
EndpointSSurrogate marker - laboratory or imaging measures
ReplicationR1Single confirmatory trial
IndependenceI0Evidence comes only from manufacturer studies
Effect sizeE+Meets the clinically important threshold

The scoring table and the verdict agree (C).

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Lower 24-hour systolic blood pressure at month 3CPlacebo-adjusted differences were -14.1 to -16.7 mm Hg, but the endpoint is a surrogate.
Fewer strokes or myocardial infarctions?This phase 2 trial did not test cardiovascular events.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
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Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Phase 2 double-blind placebo-controlled dose-ranging randomized trial at 78 sites330Funded by Alnylam Pharmaceuticals with company employees as coauthorsChange in 24-hour mean ambulatory systolic blood pressure at month 3Versus placebo: -14.1 (-19.2 to -9.0), -16.7 (-21.2 to -12.3), and -15.7 (-20.8 to -10.6) mm HgPivotal single manufacturer-funded phase 2 trial
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-08-18).

Bakris GL, Saxena M, Gupta A, et al. RNA Interference With Zilebesiran for Mild to Moderate Hypertension: The KARDIA-1 Randomized Clinical Trial. JAMA. 2024;331(9):740-749. PMID: 38363577. NCT04936035.
checked
ClinicalTrials.gov. KARDIA-1. NCT04936035.
checked
Reference 3
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-18 · Corrections: none

Cite this verdict

Zilebesiran Benefits 24-Hour Systolic Blood Pressure in Mild-to-Moderate Hypertension Evidence Grade C card
[Chamgap] Zilebesiran Benefits 24-Hour Systolic Blood Pressure in Mild-to-Moderate Hypertension — Evidence Grade C·50. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/heart/zilebesiran-mild-moderate-hypertension-24-hour-systolic-blood-pressure/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.