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Apr 5, 2021

Helping patients who do not respond to anti-VEGF therapy

by: Lynda Charters

This material belongs to Ophthalmology Times- Permission received from Saghar Bagheri, MD, PhD

Study rejects notion of ‘nonresponders’ to therapeutic option

This article was reviewed by Saghar Bagheri, MD, PhD, and Demetrios G. Vavvas, MD, PhD

Anti-vascular endothelial growth factor (VEGF) drugs reduce vision loss in patients with neovascular age-related macular degeneration (AMD). As a result, these drugs have become the primary go-to therapies for ophthalmologists.

However, a substantial number of patients do not respond to this therapy, or do so to an inadequate degree. Those calculations have been reported to range from 10% to 50% depending on the study, despite receiving monthly injections of anti-VEGF therapies.

A team of researchers from Harvard disagree with the notion that there are high percentages of patients who do not respond to anti-VEGF therapy for neovascular AMD. In fact, they claim there are no nonresponders to anti-VEGF therapy.

They maintain that the so-called non-responders actually respond, but for a shorter duration than most, according to principal investigator Demetrios G. Vavvas, MD, PhD, associate professor of ophthalmology, and co-first author Saghar Bagheri, MD, PhD, clinical research fellow at Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, at Harvard Medical School, in Boston.

The investigators pointed out that for many patients, the maximum anti-VEGF treatment effect occurs prior to the standard week-4 assessment, and on average occurs at 3 weeks postinjection.

They explain that this was anticipated by the pharmacokinetic data. For this reason, the phase 2 tolerability and efficacy study of dose escalation of ranibizumab (Lucentis, Genentech Inc) included a cohort of patients dosed at 2-week intervals.

This study showed that the 2-week interval was tolerated and showed trends for superior outcomes compared with the longer interval. However, in the phase 3 study, only monthly dosing was tested out of convenience.

The PrONTO study recorded data on weeks 1, 2, and 4 after the first injection of Lucentis (40 patients) and reported that visual acuity levels were similar at 2 and 4 weeks. They also reported that the status of subretinal or intraretinal fluid was not statistically significantly different between these time points (~30%-25% of patients had subretinal fluid).

This study, unfortunately, reported averages of all patients and did not report details on the cohort with persistent subretinal fluid.1

Read more: https://www.ophthalmologytimes.com/view/helping-patients-who-do-not-respond-anti-vegf-therapy

Source: Ophthalmology  Times

 

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