Purpose: To evaluate disease activity-free intervals of patients with neovascular age-related macular degeneration (nAMD) in the pHase III, double-masked, multicenter, randomized, Active treatment-controlled study of the efficacy and safety of 0.5 mg and 2.0 mg Ranibizumab administered monthly or on an as-needed Basis (PRN) in patients with subfoveal neOvasculaR age-related macular degeneration (HARBOR) to determine whether duration of response to previous treatment with ranibizumab informs future disease activity and need for subsequent injections.
Design: Retrospective subgroup analysis of the phase 3 HARBOR study (clinicaltrials.gov identifier, NCT00891735).
Participants: Patients from the ranibizumab 0.5 mg pro re nata arm of the phase 3 HARBOR clinical trial who received all 3 loading injections and missed no more than 1 study visit (N = 217).
Methods: A disease activity-free interval was defined as a consecutive period in months when treatment was not required because the patient did not meet protocol retreatment criteria. Percentage of disease activity-free eyes at the next 1 and 2 months after a first disease activity-free interval of ≥2, ≥3, ≥4, ≥5, and ≥6 months was evaluated. Additionally, duration that eyes remained untreated after disease activity-free intervals was evaluated by Kaplan-Meier estimates.
Main outcome measures: Key outcome measures included duration of the first treatment-free interval of ≥2, ≥3, ≥4, ≥5, and ≥6 months achieved by each patient; mean number of additional months patients remained treatment free after a treatment-free interval; and percentage of eyes requiring treatment within 2 months after each treatment-free interval.
Results: Percentage of eyes requiring retreatment the month after a treatment-free interval of ≥2, ≥3, ≥4, ≥5, and ≥6 months was 60% (90/151), 33% (33/100), 26% (20/77), 36% (24/66), and 19% (9/48), respectively. Percentage of eyes requiring retreatment within 2 months after a treatment-free interval of ≥2, ≥3, ≥4, ≥5, and ≥6 months was 73% (109/149), 53% (53/100), 53% (40/75), 47% (30/64), and 43% (20/46), respectively. After treatment-free intervals of ≥2, ≥3, ≥4, ≥5, and ≥6 months, mean (standard error of the mean) additional time treatment free was 1.3 months (0.17 month), 2.4 months (0.33 month), 2.9 months (0.44 month), 3.2 months (0.50 month), and 4.0 months (0.60 month), respectively.
Conclusions: Longer treatment-free intervals may indicate longer future disease-free intervals; however, this association varies. Thus, although longer intervals suggest greater likelihood of not needing retreatment within 1 to 2 months, regular assessment is warranted owing to the unpredictability of nAMD disease activity.
Copyright © 2019 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.