Lanadelumab,
does it really help with Prevention of attacks over 26 weeks in patients aged 12 years or older with type I or II hereditary angioedema?
research showsThe grade is C. HELP double-blind randomized 125 patients to placebo or one of three lanadelumab regimens. Mean monthly attack rates over 26 weeks were 1.97 with placebo, 0.48 with 150 mg every four weeks, 0.53 with 300 mg every four weeks, and 0.26 with 300 mg every two weeks. Rate ratios versus placebo were 0.24, 0.27, and 0.13, reductions of 73% to 87%. However, this was one 125-participant manufacturer development trial without independent replication.
ads claimAn '87% reduction' is not a value for every dose and every patient. It is the model-based placebo-relative attack-rate reduction for 300 mg every two weeks, not an individual's attack-free probability or a lifetime effect.
Useful facts when choosing a product
- The HELP primary endpoint counted investigator-confirmed attacks over 26 weeks; it was not a laboratory surrogate or quality-of-life score.
- Rate ratios were 0.24, 0.27, and 0.13; count outcomes were not converted to Cohen d.
- Dyax funded the study and participated from design through analysis and interpretation.
What the research actually shows
HELP assigned 125 patients to placebo, 41; lanadelumab 150 mg every four weeks, 28; 300 mg every four weeks, 29; or 300 mg every two weeks, 27. Every randomized patient received at least one dose and entered the intention-to-treat efficacy analysis. Everyone received injections every two weeks, with matched placebo between active doses in the four-week regimens to maintain masking. In total, 113 (90.4%) completed 26 weeks; a tipping-point analysis reported that postdiscontinuation rates would need to be 22 to 35 times the observed rates to reverse significance. The primary endpoint was investigator-confirmed HAE attacks from day 0 through 182. Dyax Corp, now Shire Human Genetic Therapies, funded the trial and participated in design, conduct, data management, analysis, interpretation, and medical review of the manuscript.
Why this is classified as C (54)
The direct clinical event rate fell substantially, but one 125-participant manufacturer-funded confirmatory trial gives C with 54 points.
Counterpoint. C does not mean a small observed effect. It grades the evidence hierarchy, which still lacks independent replication and larger long-term comparison.
Rejudgment record. Cross-check applied — A 125-participant double-blind placebo-controlled trial found large direct attack-rate effects, with rate ratios of 0.13 to 0.27, but evidence was capped by a small single-manufacturer program
| Endpoint | H | Hard endpoint - actual events such as death |
| Replication | R1 | Single confirmatory trial |
| Independence | I0 | Evidence comes only from manufacturer studies |
| Effect size | E+ | 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) | Grade | Basis |
|---|---|---|
| Reduced hereditary-angioedema attack rate over 26 weeks | C | Rate ratios across the three regimens ranged from 0.13 to 0.27 versus placebo. |
| Long-term independently replicated attack prevention | ? | The decisive evidence in this verdict is one 26-week manufacturer-funded confirmatory trial. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Multicenter double-blind placebo-controlled phase 3 randomized trial | 113 | Funded by Dyax Corp, now Shire Human Genetic Therapies | Number of investigator-confirmed hereditary-angioedema attacks from day 0 through 182 | Monthly rates 1.97 with placebo versus 0.48, 0.53, and 0.26; rate ratios 0.24 (95% CI 0.15 to 0.39), 0.27 (0.18 to 0.41), and 0.13 (0.07 to 0.24), all adjusted P<.001 | Large direct attack-rate effect from one small manufacturer-funded confirmatory trial |
Receipt — 1 References
All 1 cited sources were verified for existence at the original page (as of 2026-08-18).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-18 · Corrections: none
Cite this verdict
[Chamgap] Lanadelumab x prevention of hereditary angioedema attacks — Evidence Grade C·54. 1 cited sources checked. Source: https://chamgap.com/en/verdicts/immunity/lanadelumab-hereditary-angioedema-attack-prevention/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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.