# Efficacy and Safety of Donidalorsen for Hereditary Angioedema.

- **DOI:** [10.1056/nejmoa2402478](https://doi.org/10.1056/nejmoa2402478)
- **Rating:** Strong (4.0 out of 5)
- **Verdict:** Donidalorsen reduces hereditary angioedema attacks in a randomized phase 3 trial, but its position against established prophylaxis remains unresolved.
- **Framework version:** v5.10
- **Pipeline version:** v0.4
- **Evaluation date:** 2026-11-03
- **Evaluation page:** https://www.nabu.science/paper/10.1056%2Fnejmoa2402478

## Key claims

1. Donidalorsen at a dose of 80 mg administered subcutaneously every 4 or 8 weeks significantly reduced the hereditary angioedema attack rate
   - Support: Supported
   - Type: Primary finding
   - Basis: randomized placebo comparisons support both schedules, with less precise evidence from the smaller every-8-week group
   - Location: Discussion, final paragraph
2. a significant improvement of 24.8 points in the least-squares mean AE-QoL total score from baseline to week 25 was observed in the [donidalorsen] 4-week group
   - Support: Supported
   - Type: Secondary
   - Basis: the placebo-adjusted improvement supports benefit, although a patient-reported outcome in a small trial remains susceptible to partial unblinding
   - Location: Results, Secondary End Points
3. The most common adverse events were erythema at the injection site, headache, and nasopharyngitis; 98% of adverse events were mild or moderate in severity.
   - Support: Supported
   - Type: Secondary
   - Basis: systematic reporting supports observed event severity, but 90 participants followed for 25 weeks cannot establish uncommon or long-term harms
   - Location: Abstract, Results; Results, Safety

## Strengths

- **Randomized confirmation of clinically relevant efficacy** The phase 3 study extends prior phase 2 evidence with placebo-controlled attack-rate comparisons for two dosing intervals and patient-reported quality-of-life outcomes.
  - Dimension: contribution
  - Location: Introduction, final paragraph; Results, Efficacy; Table 2
- **Count modelling and controlled endpoint testing** The primary analysis adjusts for baseline attack rate, observed follow-up, and overdispersion. The hierarchical procedure withholds subsequent P values after the first nonsignificant test.
  - Dimension: methodological rigour
  - Location: Methods, Statistical Analysis; Table 2 footnotes
- **Clear reporting of bounded efficacy conclusions** The Abstract reports the separate placebo comparisons and confines its conclusion to potential prophylactic use rather than superiority over active treatments or established long-term safety.
  - Dimension: reporting
  - Location: Abstract, Results and Conclusions; Discussion, final paragraph

## Limitations

- **Informative withdrawal remains incompletely tested analytically** Lack-of-efficacy withdrawals occurred in three placebo participants and one participant in each active arm. Time-normalised follow-up preserves observed data but does not itself establish that subsequent missing outcomes satisfy the MAR assumption.
  - Dimension: methodological rigour
  - Location: Results, Patients; Methods, Statistical Analysis
- **Comparative prophylactic treatment positioning remains unresolved** The trial uses placebo rather than an active prophylactic comparator, and the Discussion does not closely compare competing agents' efficacy or treatment burden. The proposed induction-to-maintenance switch also lacks direct testing.
  - Dimension: positioning
  - Location: Methods, Trial Design and Oversight; Discussion
- **Small population limits broader clinical inference** Only 90 patients were treated, including seven adolescents, with limited racial diversity and 25 weeks of controlled treatment. These boundaries constrain population transferability and detection of uncommon or longer-term harms.
  - Dimension: application pathway
  - Location: Table 1; Results, Adolescent Patients and Safety; Discussion, limitations

## Reliability checks

Caveats (4 of 4 checks).

- **Results check:** Noted. One reported value does not reconcile, but the key claims do not rest on it.
  - Minor reporting notes (1):
    - Descriptive: "Reductions in trough prekallikrein concentrations from baseline to week 25 were 93% (95% CI, 81 to 105) in the 4-week group" (Results, Adolescent Patients). The reported upper confidence endpoint of 105% exceeds the 100% physical reduction bound; the unconstrained interval itself does not establish an erroneous point estimate. → Conclusion holds
- **Reporting and transparency:** Clean. Ethics approval, consent, trial registration, sponsor involvement, independent statistical analysis, and medical-writing support are disclosed. Unavailable supporting documents are assessability gaps, not demonstrated reporting misconduct.
  - Conflict of interest: declared · Ethics approval: declared · Preregistration: declared · Data availability: declared
- **Reference integrity:** Clean. 22 of 22 checkable references verified
  - 23 references in manuscript
  - 1 have no canonical index record — counted, but not index-checkable
  - 1 reference confirmed by manual review
  - References not verified automatically are resolved manually within 24 hours.

## Post-publication record

- **Status:** Clean
- **Summary:** No retraction or expression of concern found in Crossref (includes Retraction Watch).
- **Last checked:** 2026-11-03