The authors regret an error in Klamroth et al.1
The correlation analysis between individual AAV5 NAb titers at baseline and FIX expression was done using endogenous factor IX (FIX) activity at 48 months post-treatment and not from months 7-48 as stated.
This impacts the following places in the manuscript:
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In Section 2.5, Statistical analysis, the paragraph starting ‘A potential correlation between …’ should read:
“A potential correlation between individual AAV5 NAb titers at baseline and FIX expression at 48 months post-etranacogene dezaparvovec infusion was analyzed using a simple linear regression with FIX activity as the outcome and the base-10 logarithm of the AAV5 titer at baseline as the lone covariate.”
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In Section 3.3, Endogenous FIX activity, the final paragraph should read:
Notably, no clinically meaningful correlation between individual AAV5 titer at baseline and endogenous FIX activity at 48 months post-treatment was identified (Figure 2B).
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The legend of Figure 2 should read: Endogenous factor (F)IX activity (A) over the 4-year follow-up and (B) at 48 months post-treatment as a function of baseline adeno-associated viral vector serotype 5 (AAV5) neutralizing antibody titer. Horizontal lines within the boxes in A depict medians, bars depict upper and lower quartiles (quartiles 1-3), and diamonds show individual levels of expression at years 1 to 4. In B, missing data for FIX activity at month 48 post-treatment were imputed using the most recent previous uncontaminated post-treatment value that was observed for the participant. aPTT, activated partial thromboplastin time; rp, Pearson product-moment correlation coefficient; rs, Spearman correlation coefficient.
In addition there is an error in the sentence in the first paragraph of Section 3.6, Safety. This should read:
The 1 participant who returned to prophylaxis during year 3 did so due to a treatment-related AE of loss of specific f9 gene expression between months 29 and 30 post-gene therapy.
The authors would like to apologise for any inconvenience caused.
Reference
- 1.Klamroth R., Monahan P.E., Van der Valk P., et al. Etranacogene dezaparvovec in people with hemophilia B with preexisting adeno-associated virus 5 neutralizing antibodies: 4-year subgroup results from the HOPE-B trial. Res Pract Thromb Haemost. 2026 Jan 19;10(1) doi: 10.1016/j.rpth.2026.103360. [DOI] [PMC free article] [PubMed] [Google Scholar]