In Vivo evaluation of autologous serum eye drops obtained via a closed-circuit collection device: Preliminary analysis of a Phase 2 pilot trial

Abstract Introduction: Autologous serum eye drops (ASED) are an established therapy for ocular surface diseases, with reported average symptom improvements of around 50-70%.However, their preparation can be costly and may not be available due to the need for germ-free conditions. Our aim was to evaluate the feasibility and safety of ASED collected via a closed-circuit system device. Methods: This is a single-arm, phase 2 pilot trial. Adult patients with persistent dry eye disease and/or chronic corneal epithelial defects requiring ASED, as evaluated by expert ophthalmologists, were included. Twenty percent ASED were collected, processed, and frozen in single-dose containers, which patients thawed and used within 24 hours. Clinical assessments included ophthalmological evaluations (tear film breakup time, meibography, lipid layer analysis, Schirmer test, corneal/conjunctival staining with Rose Bengal and fluorescein), clinical grading (ocular NIH score), symptom questionnaires (OSDI, Lee, global score), treatment adherence, and adverse event monitoring at baseline, 6 weeks, and 12 weeks. Results: Fourteen patients were enrolled in the pilot phase: nine with ocular graft-versus-host disease (GVHD), four with Sjögren's syndrome, and one with cicatricial pemphigoid. As of May 2025, a total of 50 collections have been performed using the closed-circuit system, with three bags lost during centrifugation. No adverse events related to venipuncture or the collection process have been reported. Four patients experienced mild difficulties manipulating the single-dose containers to apply ASED, but adherence remained adequate. No issues were reported with storing containers once opened. All collections met pre-established quality criteria for irregular antibody screening, pre-freezing cultures/cellularity, and pH before and after freezing. Objective ophthalmologic evaluations showed no significant changes from baseline to 6 and 12 weeks post-treatment. Conversely, the OSDI and Lee scores significantly improved over 12 weeks (medians [interquartile range, IQR] 77 [64,92], 53 [33,70], and 45 [25,73], p=.0002; and 83 [67,100], 50 [42-75] and 58 [42,67], p=.009, at baseline, 6 and 12 weeks, respectively). The ocular NIH score also significantly improved over time (score 2 [38%] and 3 [62%] at baseline; score 1 [34%] and 2 [66%] at 6 weeks; and score 1 [11%], 2 [66%], and 3 [11%] at 12 weeks, p=.04), while the global score showed a trend for improvement (8 [IQR 7,10] at baseline, 7 [IQR 6,9] at 6 weeks, and 8 [IQR 3,8] at 12 weeks, p=.06). Three patients discontinued ASED before completing 12 weeks due to perceived lack of benefit or mild adverse events, which were transient and resolved completely upon discontinuation. Conclusion: Preliminary data suggest that our closed-circuit system production of ASED appears feasible and safe. Patients experienced symptomatic relief, while objective ophthalmic measures remained stable. This pilot study has been used in the approval for a registration trial under the Brazilian Health Regulatory Agency (ANVISA), which is set to commence enrollment shortly.