Abstract
Purpose :
The primary objective of the RadiRet study was to demonstrate superior efficacy of ranibizumab 0.5 mg to focal and peripheral laser treatment regarding change from baseline in best-corrected visual acuity (BCVA) over 6 months in patients with retinopathy due to radiation in uveal melanoma.
Methods :
A phase II, two-arm, randomized, parallel-group clinical trial. Ranibizumab was administered as three initial monthly intravitreal injections (0.5 mg, days 0, 30, 60). Subsequent injections were given if visual acuity dropped by >5 letters or evidence of macula or optic disc edema. The comparator was laser treatment of the macula and periphery. Additional treatment at intervals of not less than 3 months. Main inclusion criteria: patients with retinopathy, due to radiation of uveal melanoma (cotton wool spots, hemorrhages, vascular ischemia), visual impairment due to focal or diffuse macular edema eligible for laser treatment.
Results :
The intention-to-treat analysis included 31 patients who were randomly assigned to ranibizumab (n=15) or laser treatment (n=16). The per-protocol analysis included 19 patients (7 on ranibizumab, 12 in laser group).
Efficacy: Regarding the primary outcome measure ‘average change in BCVA from baseline over 26 weeks’ treatment with ranibizumab was superior compared to laser treatment, with a mean advantage of 0.14 logMAR, p=0.030. Subgroup analyses by dose to macula/disc and gender did not indicate any interaction with treatment. Similarly treatment with ranibizumab seemed advantageous regarding the key secondary outcome ‘average change in central foveal thickness from baseline over 26 weeks’ with a mean advantage of 51.3 µm, p=0.074. The positive effect of ranibizumab vanished following week 26, i.e. after treatment was stopped.
Safety: The safety analysis was based on all patients who were treated (n=31). 11 patients experienced at least one serious adverse event.
Conclusions :
This randomized controlled trial showed a statistically significant improvement of visual acuity under treatment with ranibizumab compared to laser treatment. The gain in BCVA that was seen in week 20 and 26 disappeared at week 52 following termination of treatment, suggesting that ranibizumab injections may need to be continued over a longer period than 20 weeks.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.