Corneal Findings in Patients Treated with Belantamab Mafodotin: A Prospective Case Series Focusing on Corneal Nerves

This prospective case series investigated corneal epithelial and subbasal nerve plexus changes associated with belantamab mafodotin (Belamaf) therapy in patients with refractory/relapsed multiple myeloma using a multimodal imaging approach.

We included eight patients (mean age 66 ± 10) scheduled for Belamaf who were monitored for at least three treatment cycles. Standard clinical eye exams with Snellen best corrected visual acuity (BCVA) measurements were complemented by epithelial thickness mapping, slit lamp photography, corneal sensitivity testing, and corneal confocal microscopy.

The mean drop in BCVA was limited to 1 line (20/25 to 20/32) with mean loss in sensitivity from 5.2 ± 0.4 to 8.7 ± 3.4 mg/S. Corneal epithelial thickness increased (from a mean of 62 ± 4.7 to 74 ± 6.2 μm) presenting an irregular pattern from the apex to the mid-periphery. All patients developed microcystic epithelial changes and ocular surface disease. Confocal microscopy revealed a decrease in mean nerve fiber length and density from 12.46 ± 4.94 mm/mm² and 21.87 ± 10.27/mm² at baseline to 3.27 ± 3.9 mm/mm² and 1.78 ± 3.22/mm² at last follow-up, respectively, with preserved limbal architecture.

This prospective study confirms and further characterizes the pathognomonic epithelial changes caused by Belamaf, which are accompanied by severe impairment in subbasal nerve fiber architecture, indicating a neurotoxic effect of the medication that requires further investigation.