Sales of drugs to treat age-related macular degeneration in the G7 pharmaceutical markets are set to grow 6% a year, reaching nearly $9 billion in 2023, say new forecasts.

The forces combining to drive growth in these markets - the US, France, Germany, Italy, Spain, the UK and Japan - include increasing prevalence of AMD due to population aging, rising rates of polypharmacy and the anticipated uptake of the first agents for the treatment of geographic atrophy - the advanced dry form of AMD, says the research, from Decision Resources.

Following a projected launch in the second half of the 2013-23 forecast period, Roche/Genentech’s lampalizumab will become the first agent approved for the treatment of geographic atrophy, and this clinical and commercial milestone will lead to the advent and rapid expansion of this market segment, says the report. It also expects lampazilumab to achieve blockbuster sales peaking beyond 2023, despite early competition from Acucela/Otsuka’s geographic atrophy treatment emixustat hydrochloride, which is expected to launch shortly after lampalizumab.

With expected growth in diagnosis and prescription drug-treatment rates, and the assumption of premium pricing for emerging agents, the G7 market for geographic atrophy therapies is expected to cross the billion-dollar threshold rapidly, within three years of the first launch, says the report.

Monotherapy with the current mainstay treatments for wet AMD - Roche/Genentech/Novartis’ Lucentis (ranibizumab), Regeneron/Bayer HealthCare’s Eylea (aflibercept) and off-label use of Roche/Genentech/Chugai’s Avastin (bevacizumab) - will continue to dominate wet AMD treatment. The 2018 launch of Ophthotech/Novartis’ Fovista (anti-platelet-derived growth factor [PDGF] aptamer) will formalise and substantially expand combination treatment for the disease, adding over $500 million to the AMD market in 2023, it adds.

“As an adjunctive treatment, Fovista will avoid direct competition with established wet AMD agents. Its commercial success, however, will depend on whether pricing and reimbursement terms will be favourable in the major markets, based on a cost/benefit analysis of its value as an additive treatment, and how widely physicians would incorporate this regimen-based approach in wet AMD,” comments Decision Resources group analyst Nadja Rozovsky.

“The focus of the Fovista Phase II trials in additional patient subgroups, such as those at risk for subretinal fibrosis or who are refractory to currently-available VEGF [vascular endothelial growth factor] inhibitor therapies, likely will drive endorsement among retinal specialists and payers alike,” Dr Rozovsky adds.

The report also forecasts that biosimilar versions of wet AMD mainstay treatments due to launch in the second half of the forecast period will lead to moderate brand share erosion, while in the nearer term, efforts by some European governments to formally permit the off-label use of Avastin for wet AMD will temper the patient share of approved VEGF inhibitors.