4D Molecular Therapeutics Reports Positive 2-Year PRISM Phase 2b Data

What Happened
4D Molecular Therapeutics (filed 8-K July 20, 2026) announced positive 2-year results from its PRISM Phase 2b trial of single intravitreal doses of gene therapy 4D-150 for wet age-related macular degeneration (data cutoff May 18, 2026). The trial enrolled 45 patients across two dose levels (3E10 vg/eye and 1E10 vg/eye); the 3E10 dose (n=30) was selected for the ongoing 4FRONT Phase 3 program. The data show maintained visual acuity (BCVA), stable central subfield thickness (CST), and durable reductions in supplemental anti-VEGF injections through two years.

Key Details

• Trial enrollment and dosing: 45 patients in Phase 2b (30 at 3E10 vg/eye; 15 at 1E10 vg/eye); a subgroup of recently diagnosed patients (≤6 months) included 15 patients at 3E10.
• Treatment-burden reduction vs. on-label aflibercept (projected 12.0 injections over 2 years): overall cohort showed 78% reduction (mean 2.7 supplemental injections); recently diagnosed subgroup showed 87% reduction (mean 1.6 supplemental injections).
• Safety (Phase 1/2a + 2b, n=71 for Phase 3 dose): 2.8% (2 of 71) experienced transient, mild (1+) intraocular inflammation within ~28 weeks; no new IOI cases after week 28 through up to >4 years follow-up. No 4D-150–related hypotony, endophthalmitis, vasculitis, retinal occlusion, or choroidal effusions reported to date.

Why It Matters
These two-year data support durability and a favorable safety signal for single-dose 4D-150 and justify using the 3E10 vg/eye dose in Phase 3 (4FRONT). For investors, the results indicate potential to substantially reduce the frequent anti-VEGF injection burden for wet AMD patients if later trials confirm efficacy and safety. The company’s 8-K also includes standard forward-looking statement disclaimers; outcomes remain subject to clinical, regulatory, and business risks described in 4D’s SEC filings.