Growth slowed, vision still lost: two years of pegcetacoplan

Design

retrospective interventional case series with prospective swept-source optical coherence tomography angiography imaging

Population

77 eyes of 58 patients with symptomatic geographic atrophy treated for two years

Primary outcome

square-root geographic atrophy growth rate and best-corrected visual acuity at two years

Effect

growth 0.33 to 0.19 mm/year, a 41% reduction (P<0.001); acuity fell from 63 to 55 letters (P<0.001)

Seventy-seven eyes of 58 patients with symptomatic geographic atrophy secondary to age-related macular degeneration completed two years of 15 mg intravitreal pegcetacoplan, averaging 18 ± 3 injections at intervals of about 1.3 months, with swept-source optical coherence tomography angiography before and during treatment.

Square-root atrophy growth during treatment was 0.22 ± 0.12 mm/year across 72 measurable eyes. In the 49 eyes with annual visits before treatment, growth fell from 0.33 ± 0.21 mm/year to 0.19 ± 0.11 mm/year, a 41% reduction (P<0.001), and 71 of 72 eyes either slowed further or held steady in the second year — the single exception was also receiving anti-vascular endothelial growth factor therapy for exudative neovascularisation. Foveal and non-foveal atrophy behaved the same. Eyes that were growing fastest before treatment showed the greatest proportional inhibition (r=0.40, P=0.007 at two years).

And best-corrected acuity fell, from 63 ± 14 to 55 ± 16 letters over the two years (P<0.001) — roughly a line and a half. That is the sentence to have ready when a patient asks what eighteen injections bought. The honest answer is that the lesion enlarged more slowly and the vision still deteriorated, and there is no functional endpoint in this series showing the patient is better off.

That conversation is the whole clinical content here. Eighteen injections over two years is a substantial burden of clinic visits, cost and injection risk, and in India the drug's access and price make the calculation harder still. The correlation with baseline growth rate is the most useful selection signal: the fast progressor has most to gain.

• Measure square-root atrophy growth rate before starting, where prior imaging exists — the fast progressor gained most here
• State plainly at consent that slowed lesion growth has not been shown to preserve acuity in this series
• Count the treatment burden explicitly: about 18 injections and 18 visits over two years
• Watch for new exudative neovascularisation; the single eye that worsened had it
• Do not expect a difference between foveal and non-foveal atrophy in growth response

Why it matters

It sets out what a patient actually gets for two years of injections, and what they do not.

Don't overread it

A retrospective single-centre series with no control arm — slowed lesion growth here is not evidence of preserved vision.

The statistics, in plain English

There is no control group, so the 41% reduction is a before-and-after comparison within the same eyes — and atrophy growth naturally varies, with fast-growing lesions tending to slow over time (regression to the mean). That phenomenon also explains the correlation between faster baseline growth and greater apparent inhibition, which should therefore be held loosely. The acuity decline, by contrast, is a directly observed outcome: 63 to 55 letters with P<0.001. The 71-of-72 consistency in the second year is the most persuasive element, because a purely statistical artefact would be unlikely to run one way in nearly every eye.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.