Purpose
To describe baseline characteristics of the BAM114341 study population.
Methods
BAM114341 is a double masked, placebo-controlled clinical study to investigate the safety and efficacy of a humanized monoclonal antibody directed against β-amyloid in patients with GA secondary to AMD. The ongoing study included a 4-month run-in observation period where baseline growth rates of GA lesions were established to use pre-treatment patient-specific growth rates for comparison with those after randomization for a period of 18 months. It randomized 191 patients with a GA total area of 1.9 - 17 mm2 at the screening visit. Monthly measures of GA lesion size by color fundus photography (CP) and fundus autofluorescence (FAF) were taken for the run-in period. A mixed effects model was created to estimate GA lesion growth rate. The demographics of the study population, the model estimate of the GA lesion growth rate and the concordance of the CP and FAF measurements evaluated by Bland-Altman analysis are described.
Results
The average age at screening was 77.2 years (range, 55-95 years, SD 8.6 years), and 57% of the cohort was female. Average baseline BCVA was 62.7 (SD=14.8) letters. 85% of patients had bilateral GA and 59% of patients had study eye central involvement. The average GA lesion size at screening in the study eye by CP was 7.72 mm2 (SD 4.52 mm2). The average change in GA lesion size during the run-in was estimated as 0.78 mm2 (95% CI 0.57-0.98 mm2) and 0.76 mm2 (95% CI 0.61-0.92 mm2) for CP and FAF, respectively. Model based growth rates for CP and FAF in the run-in period were 0.66 mm2 and 0.64 mm2. These values extrapolate to annualized growth rates of 2.16 mm2 (95% CI 1.75-2.54 mm2) and 2.06 mm2 (95% CI 1.70-2.41 mm2) for CP and FAF, respectively. These are consistent with values reported in the literature; i.e. Sunness, et al (Ophthalmology 2007;114:271-277) reported 2.6 mm2 per year for CP and Holz, et al (IOVS 2011;52:6552-6557) 1.64 mm2 for FAF. Moreover,the CP and FAF measurements showed agreement (average difference 0.11 mm2, SD 1.37 mm2, with 95% limits of agreement of -2.80 mm2, 2.54 mm2).
Conclusions
The BAM114341 measurements by CP and FAF over the 4 month observation period were in agreement, and the estimated growth rate reflects other GA cohorts in the literature.