A large, global extension study following more than 1,400 people with diabetic macular edema (DME) reports that patients maintained earlier vision and retinal-thickness improvements for up to 4 years while many stretched treatment intervals to 12-16 weeks on a treat-and-extend schedule.

The findings come from RHONE-X (NCT04432831)—a 2-year, open-label extension of the phase 3 YOSEMITE and RHINE trials—recently published in Ophthalmology.

RHONE-X enrolled 1,474 participants who completed YOSEMITE/RHINE and transitioned them—without mandatory “restart” monthly loading doses—onto faricimab treat-and-extend dosing up to every 16 weeks, adjusted by visual acuity and retinal thickness criteria. In the parent trials, patients had previously been assigned to faricimab every 8 weeks, faricimab treat-and-extend, or aflibercept every 8 weeks; in RHONE-X, everyone ultimately received faricimab treat-and-extend.

Over 2 years of RHONE-X follow-up:

  • Treatment discontinuation due to adverse events: 1.5%

  • Intraocular inflammation: 1.3%

  • No reports of retinal vasculitis or occlusive retinal vasculitis were observed in the study’s reporting.

Overall safety was described as consistent with earlier YOSEMITE/RHINE experience.

Vision, anatomy, and “dry” retina outcomes

Across the full 4-year period (YOSEMITE/RHINE + RHONE-X), faricimab treat-and-extend maintained improvements:

  • Average vision gains from original baseline to study end: about +9.5 to +11.4 ETDRS letters, depending on prior treatment group

  • Central subfield thickness reductions: about –198 to –205 µm by study end

  • Absence of DME (defined as CST < 325 µm): >90% of patients at the end of the extension, including those who had previously received aflibercept

The durability signal was one of the headline results:

  • Median injections over the 2-year extension: 7–8 injections total (roughly 3 injections in the second year of RHONE-X for many patients)

  • By completion, ~80% of participants were on ≥ every-12-week dosing, and more than 60% reached every-16-week intervals

RHONE-X was open-label and non-randomized (an extension design), meaning it wasn’t built to re-test head-to-head superiority. Also, visit timing became more variable once patients were only seen at dosing visits, and outcomes were analyzed using predefined “windows” rather than strict monthly measurements.