Background
Proliferative diabetic retinopathy (PDR) represents a severe complication of diabetes, characterized by abnormal blood vessel growth in the retina, which can lead to vision loss if untreated. Traditional treatment with panretinal photocoagulation (PRP) laser therapy, while effective, often causes peripheral vision loss and other complications. The CONDOR trial evaluated brolucizumab, an anti-VEGF therapy, as a potential alternative to PRP.
Study Design
CONDOR was a 96-week, multicenter, phase 3 randomized clinical trial involving 689 participants across 152 sites in 16 countries. Patients were randomized 1:1 to receive either brolucizumab (6 mg) or PRP. The brolucizumab regimen included three loading doses every 6 weeks, followed by maintenance doses every 12 weeks, with possible interval extensions based on disease activity. PRP was administered in 1-4 sessions up to week 12, with additional treatments as needed.
Key Findings
The primary outcome, change in best-corrected visual acuity (BCVA) at week 54, showed brolucizumab was superior to PRP (mean letter score change: +0.2 vs -4.2; difference 4.4, 95% CI 2.4-6.4, P<.001). Significantly more brolucizumab-treated patients achieved PDR resolution (63.6% vs 22.4%, P<.001). However, ocular adverse events, including intraocular inflammation (5.2% vs 0.6%), were more common with brolucizumab.
Expert Commentary
While brolucizumab demonstrates clear efficacy advantages, the higher rate of inflammatory complications warrants careful patient selection and monitoring. The ability to extend treatment intervals based on disease activity offers practical benefits but requires further real-world validation.
Conclusion
The CONDOR trial establishes brolucizumab as a superior alternative to PRP for PDR treatment, though safety monitoring remains crucial. This may lead to reconsideration of first-line therapy choices in PDR management.
Funding and Registration
Supported by Novartis Pharma AG. Registered at ClinicalTrials.gov (NCT04278417).