Which factor predicts successful interval extension in eyes with nAMD switched to brolucizumab?

In patients with neovascular age-related macular degeneration (nAMD) who switched to brolucizumab treatment, those with shorter treatment interval before switching are more likely to have successful injection interval extension, as shown in a study.

“Treatment-experienced patients who required more frequent injections (ie, shorter intervals before switching) showed the greatest extensions when switching to brolucizumab,” the investigators said.

This retrospective, observational cohort study included 1,890 adults in the US-based IRIS Registry with nAMD who switched from another antivascular endothelial growth factor (anti-VEGF) agent to brolucizumab-only treatment for ≥12 months from 8 October 2019 through 26 November 2021.

Univariable and multivariable analyses were conducted to explore the associations of demographic and clinical characteristics with the odds of interval extension after switching to brolucizumab therapy.

The investigators classified eyes into extenders or nonextenders at 12 months. Extenders were eyes that achieved (1) an extension of ≥2 weeks in the brolucizumab injection interval at 12 months vs the interval before switching and (2) stable (<10 letters gained or lost) or improved (≥10 letters gained) visual acuity (VA) at 12 months vs VA at index injection.

A total of 2,015 eyes were examined, of which 1,186 (58.9 percent) were extenders. Univariate analysis revealed similar demographic and clinical characteristics between extenders and nonextenders, but extenders had shorter intervals prior to switching (mean, 5.9 vs 10.1 weeks).

Multivariate analyses showed a positive and significant association between a shorter interval before switching and interval extension with brolucizumab therapy (adjusted odds ratio, 5.6, 95 percent confidence interval [CI], 4.5‒6.9; p<0.001).

Additionally, eyes with an index VA of 40 to 65 letters were less likely to be extenders than those in the higher (better) index VA categories.

“With careful consideration of benefits and risks, brolucizumab may be a valuable option for patients with higher treatment burdens because of the need for frequent injections,” the investigators said.