Disease focus

Geographic Atrophy (GA) secondary to dry Age-related Macular Degeneration (AMD)

Two elderly blind people on a bench in the park

About Geographic Atrophy secondary to dry Age-related Macular Degeneration

Age-related macular degeneration (AMD) is a retinal disease that can blur your central vision. It occurs when aging causes damage to the macula, the part of the eye that controls sharp, straight-ahead vision. AMD is a leading cause of blindness worldwide, particularly in higher-income countries.

Age-related macular degeneration is a progressive retinal disease that can blur central vision.  It is a multifactorial condition, most commonly affecting individuals over the age of 50, and involves damage to the macula – the part of the eye responsible for sharp, straight-ahead vision.¹˒² AMD is a leading cause of vision loss worldwide with prevalence increasing as populations age²,³

AMD progresses through early, intermediate, and advanced stages¹. Advanced AMD can manifest in two forms:

  • Geographic Atrophy (GA), the advanced atrophic stage of dry AMD¹˒² 
  • Neovascular (wet) AMD, characterised by the growth of abnormal blood vessels beneath the retina¹

While early and intermediate stages often progress gradually with mild visual impact, advanced AMD can lead to significant and irreversible vision loss¹.

GA develops through the progressive loss of key retinal structures, including photoreceptors, the retinal pigment epithelium (RPE), and the underlying choriocapillaris². These areas of degeneration expand over time, resulting in worsening central vision loss.

Learn more about GA here.

Close-up of man having his eye tested by doctor
Female doctor explaining test results to elderly patient

In numbers:

1
AMD is a leading cause of blindness worldwide5
25%
Of AMD-related blindness is due to GA2,7
>5 million
Patients with GA globally2,7
>1 million
Cases of GA in the US alone8

Treatment

AAV Gene Therapy

BTX-001

BTX-001 is an adeno-associated virus (AAV)- based gene therapy candidate being evaluated for the treatment of geographic atrophy (GA) secondary to dry Age-related Macular Degeneration (AMD). The therapy is designed to target a clinically validated complement pathway through delivery of a C5 inhibitor administered as a single intravitreal injection, combining the potential for sustained treatment effect with the convenience of in-office delivery.

BTX-001 incorporates a potent capsid optimized for intravitreal delivery9, enabling targeted and sustained expression in the retina with a favorable inflammatory profile in preclinical studies.

Current treatment options for GA require repeated intravitreal injections, which may limit patient adherence and increase treatment burden10,11 BTX-001 has the potential to reduce patient burden through a one-time, in-office treatment designed to provide sustained therapeutic effect.

 

References

1. Armento A, et al. Cell Mol Life Sci. 2021;78(10):4487-4505; 2. Boyer DS, et al. Retina. 2017;37(5):819-835; 3. Wong WL, et al. The Lancet Global Health. 2014;2(2):e106e116; 4. Rush RB et al. Clin Ophthalmol. 2025;19:1167-1174; 5. World Health Organization (WHO), “Blindness and Vision Impairment” fact sheet, Aug 2023; 6. Access Economics, prepared for AMD Alliance International, The Global Cost of Visual Impairment, 2010; 7. Chakravarthy U, et al. Ophthalmology. 2018;125(6):842-849; 8. Friedman DS, et al. Arch Ophthalmol. 2004;122(4):564-572; 9. Data on file, Beacon Therapeutics (USA), Inc.; 10. Rowe LW, et al. Expert Opin Pharmacother. 2025;26(8):939-952;11. Rush RB et al. Clin Ophthalmol. 2025;19:1167-1174. 

Female doctor explaining test results to elderly patient