4D-150

4D-150 is an investigational one-time intravitreal AAV gene therapy that expresses aflibercept and a microRNA targeting VEGF-C from the evolved R100 capsid, so it is intended to replace repeated anti-VEGF injections rather than to extend the interval between them. It is not approved in any country, no biologics license application or other marketing application has been announced, and its regulatory standing consists of FDA regenerative medicine advanced therapy designation for wet AMD granted in December 2023 and EMA PRIME designation granted in October 2023. Phase 3 design was aligned with the FDA under RMAT designation and with the EMA and the Japan Pharmaceuticals and Medical Devices Agency, using noninferiority margins of 4.5 letters for the FDA and approximately 4 letters elsewhere.

Evidence maturity is early relative to the claim being made. Seventy-one participants have received the phase 3 dose across the phase 1/2 PRISM trial, and the only randomized comparison against an active control is a 24-week analysis of 51 participants in which the BCVA difference versus aflibercept had a confidence interval spanning -7.6 to 4.1 letters. The results that carry the durability claim, a 78% reduction in injections at 2 years in 30 participants and 87% in the 15-participant recently diagnosed subgroup, come from an open-label single-arm cohort in which burden was measured against a modeled on-label aflibercept schedule rather than against observed comparator injections. The evidence gap is therefore both large and direct: no randomized phase 3 result exists, and the registration trials (523 participants randomized in 4FRONT-1 and more than 500 expected in 4FRONT-2) test noninferiority of BCVA change at 52 weeks with supplemental aflibercept permitted in both arms and randomization restricted to participants with a documented anatomic response to aflibercept during a run-in, so they are designed to show comparable vision with fewer injections in a selected population, not superior vision. Topline 52-week data are expected in the second quarter of 2027 and the second half of 2027.

Safety signals reported so far are limited but reassuring within the size of the dataset. Intraocular inflammation occurred in 2 of 71 participants (2.8%) at the phase 3 dose, was graded 1+ and transient, and no new cases were reported with 2 to more than 4 years of follow-up; no 4D-150-related hypotony, endophthalmitis, vasculitis, retinal vascular occlusion, or choroidal effusion has been observed, and no 4D-150-related serious adverse events have been reported. All participants received an approximately 20-week prophylactic topical corticosteroid taper, and 70 of 71 (99%) remained off steroids afterward. A sample of 71 participants cannot exclude uncommon events, adverse event frequency tables have not been published, and class considerations for AAV therapy remain, including vector-directed immune responses, pre-existing neutralizing antibodies to the capsid, and the irreversibility of a one-time treatment. Inflammation risk in this class appears dose- and route-dependent: about 23% of participants in an early suprachoroidal ABBV-RGX-314 cohort had mild inflammation, and inflammation with ixoberogene soroparvovec led to selection of a lower dose with topical-only prophylaxis.

The comparator is effective but imperfectly delivered. Intravitreal anti-VEGF therapy is first-line treatment in the AAO Preferred Practice Pattern, with labeled maintenance intervals from every 4 weeks for ranibizumab to every 8 to 16 weeks for aflibercept 8 mg; participants completing 96 weeks in PULSAR received a mean of 8.2 to 12.8 injections, and through 2 years in TENAYA and LUCERNE the median was 10 faricimab injections versus 15 for aflibercept. In routine United States care, a mean of 7.3 injections in the first year produced a mean gain of 0.95 letter across 49,485 treatment-naive eyes, 2,003 of 9,007 patients (22.2%) were lost to follow-up, and up to 50% of patients stopped treatment by 24 months; at 5 years in CATT, mean acuity was 3 letters below baseline and 11 letters below the 2-year value. Existing options that reduce visit frequency carry their own risks, including a boxed warning for an up to 3-fold higher rate of endophthalmitis with the surgically implanted port delivery system and labeled warnings for retinal vasculitis and retinal vascular occlusion with brolucizumab. Anti-VEGF therapy is paid under Medicare Part B, where ranibizumab and aflibercept were reported to account for 12% of the annual Part B budget.

For a pharmacy and therapeutics committee, 4D-150 is not a formulary decision in 2026, and the practical question is what evidence to require when phase 3 data arrive. What remains unknown is whether noninferior vision with reduced injections is confirmed in a randomized trial; whether the effect persists beyond 2 years, since registered outcomes extend only to week 104 and long-term follow-up is planned through year 5; whether results generalize to aflibercept non-responders, patients with longer disease duration or extensive prior treatment, central subfield thickness above 500 µm, or pre-existing neutralizing antibodies to the capsid; whether redosing or fellow-eye treatment is feasible; and what the product will cost, since no price, coverage policy, cost-effectiveness analysis, or budget impact model exists. Until a price is disclosed, the comparison that determines value, a single administration against a lifetime of injections that carry Medicare Part B payment limits of roughly $255 to $2,389 per injection at labeled doses, cannot be made.