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. 2865 · Search date 2026-08-18 · Methodology v0.7

Givosiran,
does it really help with Reduced annualized composite attacks in recurrent acute intermittent porphyria?

30-Second Summary
C
Evidence Grade C · 50 · Safety warning
Recurrent attacks fell substantially, but the small manufacturer trial and hepatic and renal harms limit certainty
ALT above three times the upper limit occurred in 15% versus 2%, renal adverse events in 15% versus 7%, and injection-site reactions in 25% versus 0%. Long-term follow-up reported homocysteine elevation in 16%, supporting liver, kidney, and homocysteine monitoring.
What the
research shows
The grade is C. Among 89 ENVISION participants with acute intermittent porphyria, the annualized composite attack rate based on six months was 3.2 with givosiran versus 12.5 with placebo, 74% lower (P<.001), an absolute difference of 9.3 attacks per person-year. The trial was double-blind and placebo-controlled, but randomized only 94 people, was funded by Alnylam, and included eight company employee coauthors. Hepatic, renal, and injection-site harms increased, giving C with 50 points.
What the
ads claim
Korea approved Givlaari for acute hepatic porphyria in 2025, and AIP is a nationally managed rare disease under special registration V118 and medical-cost support. Exact Korean AIP patient count and current drug reimbursement or ceiling price could not be verified in public national data and require HIRA and prescribing-center confirmation.
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Useful facts when choosing a product

  • The primary AIP analysis included 89 people and the full randomized sample 94, limiting precision in an ultra-rare disease.
  • ALT over three times the upper limit occurred in 7/48 (15%) versus 1/46 (2%); renal adverse events were 15% versus 7%, and injection-site reactions 25% versus 0%.
  • Long-term ENVISION follow-up reported increased blood homocysteine in 15/94 givosiran-treated patients (16%), including two serious events.
Gap Measurement · Verdict 2865 · C 50
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Thirty-six sites in 18 countries randomized 94 acute hepatic porphyria patients, 48 versus 46; the primary AIP analysis included 89. Randomization was 1:1 and double-blind, stratified by AHP subtype, prior prophylactic hemin, and historical attack rate, with matching placebo. Defect name: Small study. Listed item: Small study, total under 200. Original evidence that the requirement was met: "A total of 94 patients underwent randomization." Avoidability: Avoidable - although exceptionally difficult for this ultra-rare disease, expanding international sites and recruitment duration could have enrolled at least 200 participants. Short duration was not counted because the six-month primary period exceeded 12 weeks. Alnylam Pharmaceuticals funded the trial, and Penz plus Chen, Liu, Ko, Sweetser, Garg, Vaishnaw, Kim, and Simon disclosed current or former employment and equity or options.

02

Why this is classified as C (50)

A large blinded placebo-controlled reduction is limited by a clinician-dependent composite, one 94-patient rare-disease trial, Alnylam-only evidence, and hepatic and renal harms, giving C with 50 points.

Counterpoint. The attack reduction is a major clinical signal. Long-term safety and independent real-world data must refine the benefit-harm balance.

Rejudgment record. Direct source verification — Large double-blind placebo-controlled attack reduction, clinician-dependent composite, 94-patient rare-disease sample, and Alnylam funding

Scoring profile behind this grade
EndpointPPatient-reported treatment goal - the symptom is the goal
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
Reduced recurrent composite attack rateCRates were 3.2 versus 12.5 per person-year, an absolute difference of 9.3.
Established long-term safetyDHepatic, renal, and homocysteine abnormalities plus the small sample prevent established long-term safety.

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.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Study 1Randomized double-blind placebo-controlled phase 3 trial at 36 sites in 18 countries89Funded by Alnylam Pharmaceuticals, with multiple employee coauthors and disclosed equity or optionsAnnualized composite attacks resulting in hospitalization, urgent care, or intravenous hemin at home3.2 versus 12.5 attacks per person-year; 74% relative reduction (P<.001); absolute difference -9.3 per person-yearLarge placebo-controlled attack reduction, limited by one 94-patient manufacturer trial
Study 2Open-label extension safety report from the same ENVISION trial94Alnylam Pharmaceuticals sponsorship and employee coauthorsLong-term adverse events including hepatic, renal, and homocysteine eventsIncreased blood homocysteine in 15/94 (16%), serious in twoLong-term safety extension of the same trial, not independent replication
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Receipt — 3 References

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

Balwani M, Sardh E, Ventura P, et al. Phase 3 Trial of RNAi Therapeutic Givosiran for Acute Intermittent Porphyria. N Engl J Med. 2020;382(24):2289-2301. PMID: 32521132. DOI: 10.1056/NEJMoa1913147.
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Ventura P, Bonkovsky HL, Gouya L, et al. Efficacy and safety of givosiran for acute hepatic porphyria: final results of the randomized phase III ENVISION trial. J Hepatol. 2023;79(5):1150-1162. DOI: 10.1016/j.jhep.2023.06.013.
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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

Givosiran Benefits Recurrent Attacks in Acute Intermittent Porphyria Evidence Grade C card
[Chamgap] Givosiran Benefits Recurrent Attacks in Acute Intermittent Porphyria — Evidence Grade C·50. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/general/givosiran-recurrent-attacks-acute-intermittent-porphyria/ · 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.