Ocular Safety Evaluation of Bemarituzumab in FGFR2b-Overexpressing Gastroesophageal Adenocarcinoma: A 42-Week Follow-Up Study.

PURPOSE: To assess the duration, reversibility, alterations and prognosis of ocular adverse events (AEs) in participants treated with bemarituzumab, a first-in-class FGFR2b-targeted inhibitor in FGFR2b-overexpressing gastric/gastroesophageal junction cancer (G/GEJC), and to propose early intervention management strategy.

METHODS

This was a prospective, observational study of 11 participants with FGFR2b-overexpressing G/GEJC treated with bemarituzumab. All participants received ocular evaluations at baseline, and subsequent 6-week intervals. Evaluations included best-corrected visual acuity (BCVA), dry eye examinations, corneal morphology analysis, and fundus photography.

RESULTS

11 participants occurred ocular AEs, 8 participants finished the study. BCVA loss was first detected on day 131.5 ± 40.2 post-baseline (6.6 ± 2.5 doses following the initial bemarituzumab administration), with a loss of 2.1 ± 0.7 lines. Ocular Surface Disease Index (OSDI) scores increased (55.1 ± 18.1) at week 18. Corneal alterations manifested as punctate epitheliopathy, arc-shaped corneal defects, and ulcerative keratitis. In vivo confocal microscopy (IVCM) demonstrated features of corneal dysmaturation, including intraepithelial microcysts and abnormally thickened, cord-like structures within the basement membrane layer. After 134.1 ± 55.0 days of administering topical eye drops, the BCVA, dry eye and corneal epithelial alterations returned to baseline levels. Prophylactic administration of FGF-based eye drops helped prevent bemarituzumab treatment discontinuation, alleviated drug-related ocular symptoms, and improved prognosis.

CONCLUSIONS

The ocular AEs occurred frequently in patients receiving bemarituzumab, requiring close ophthalmic monitoring and prophylactic administration of FGF-based eye drops. Collaboration between oncologists and ophthalmologists is critical for the timely management of treatment-related AEs, which could ultimately improve overall clinical outcomes.