Evaluation of Month-24 Efficacy and Safety of Epimacular Brachytherapy for Previously Treated Neovascular Age-Related Macular Degeneration: The MERLOT Randomized Clinical Trial

Timothy L. Jackson*, Cristina Soare, Caroline Petrarca, Andrew Simpson, James E. Neffendorf, Robert Petrarca, Alyson Muldrew, Tunde Peto, Usha Chakravarthy, Luke Membrey, Richard Haynes, Mark Costen, David Steel, Riti Desai

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Importance: Although anti-vascular endothelial growth factor (VEGF) treatment offers better outcomes than the natural history of neovascular age-related macular degeneration (ARMD), a less burdensome, less expensive, and more durable treatment is needed. Objective: To assess the efficacy and safety of epimacular brachytherapy (EMB) for chronic, active, neovascular ARMD. Design, Setting, and Participants: The Macular Epiretinal Brachytherapy vs Ranibizumab (Lucentis) Only Treatment (MERLOT) pivotal device trial was conducted at 24 National Health Service hospitals across the UK. Patients who had neovascular ARMD and received intravitreal ranibizumab were enrolled between November 10, 2009, and January 30, 2012. Eligible patients were randomized 2:1 and were stratified by lens status and angiographic lesion type to receive either EMB plus as-needed ranibizumab or as-needed ranibizumab monotherapy. Participants were followed up monthly for 24 months and then assessed at a final visit at month 36. Masking of participants and clinicians was not possible, but best-corrected visual acuity (BCVA) and imaging were analyzed by masked assessors. Analysis followed the intent-to-treat approach. Interventions: Pars plana vitrectomy with 24 Gy EMB plus as-needed ranibizumab vs as-needed ranibizumab monotherapy. Main Outcomes and Measures: Coprimary outcomes were the number of as-needed ranibizumab injections and the mean change in Early Treatment Diabetic Retinopathy Study (ETDRS) BCVA with a noninferiority margin of -5 ETDRS letters. Secondary outcomes were the percentage of participants losing fewer than 15 ETDRS letters and gaining 0 or more or 15 or more ETDRS letters and the mean change in angiographic total lesion size, choroidal neovascularization size, and foveal thickness on optical coherence tomography. Results: Of 363 participants, 329 (90.6%) completed 24 months of follow-up (222 participants in the EMB group and 107 in the ranibizumab group). The mean (SD) age of the combined groups was 76.5 (7.4) years. The mean (SD) number of ranibizumab injections was 9.3 (6.7) in the EMB group and 8.3 (4.5) in the ranibizumab group, with a difference of 1.0 injection (95% CI, -0.3 to 2.3; P =.13). The mean (SD) BCVA change was -11.2 (15.7) ETDRS letters in the EMB group and -1.4 (10.9) ETDRS letters in the ranibizumab group, with a difference of 9.8 ETDRS letters (95% CI, -6.7 to -12.9). In the EMB group, 65.6% of participants (160 of 244) lost fewer than 15 ETDRS letters vs 86.6% (103 of 119) in the ranibizumab group, with a difference of 21% (95% CI, 12.4%-29.5%; P <.001). Microvascular abnormalities occurred in 20 of 207 eyes (9.7%) in the EMB group and 1 of 97 eyes (1.0%) in the ranibizumab group. These abnormalities occurred outside the foveal center, and there were no unexpected safety concerns. Conclusions and Relevance: The MERLOT trial found that despite the acceptable safety of EMB, it did not reduce the number of ranibizumab injections and was associated with worse visual acuity than anti-VEGF treatment alone; these results do not support EMB use as an adjunct treatment for chronic, active neovascular ARMD. Trial Registration: ClinicalTrials.gov Identifier: NCT01006538.

Original languageEnglish
Pages (from-to)835-842
Number of pages8
JournalJAMA Ophthalmology
Issue number8
Early online date09 Jul 2020
Publication statusEarly online date - 09 Jul 2020

Bibliographical note

Funding Information:
reported receiving an unrestricted educational grant from NeoVista and support from the National Institute for Health Research (NIHR) Clinical Research Network during the conduct of the study; receiving personal fees from Opthea, free use of medical device from Zeiss/Oraya, and site payments to employer from Roche and Novartis outside the submitted work; and serving as chief investigator in an NIHR-funded clinical trial of stereotactic radiotherapy for wet age-related macular degeneration. Dr Neffendorf reported receiving site payments to employer from Novartis outside the submitted work. Dr Chakravarthy reported receiving grants from King’s College London during the conduct of the study. Dr Steel reported receiving site payments from King’s College London during the conduct of the study, grants and personal fees from Alcon, grants from Bayer, and personal fees from Roche and Gyroscope outside the submitted work. No other disclosures were reported.

Funding Information:
Funding/Support: This study was funded by the NIHR Comprehensive Clinical Research Network (all participating sites) and by an unrestricted research grant from NeoVista (Prof Jackson).

Funding Information:
in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. The study was sponsored by King's College Hospital and undertaken by King’s College Hospital and King’s College London.

Publisher Copyright:
© 2020 American Medical Association. All rights reserved.

Copyright 2020 Elsevier B.V., All rights reserved.

ASJC Scopus subject areas

  • Ophthalmology

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