Belantamab Mafodotin Related Corneal Microcyst-Like Epithelial Changes

The aim of this study is to show the clinical evolution of 4 patients with refractory multiple myeloma (MM) that started Belantamab Mafodotin, a new and promising treatment for their disease. All of them experienced corneal adverse events but in different grades and only one needed to withhold the infusions. Corneal microcyst-like epithelial changes represent an off-target effect of Belantamab mafodotin in the cornea, leading to apoptosis of epithelial cells which are eventually replaced with new ones. 

Belantamab mafodotin is an antibody-drug conjugate against B-cell maturation antigen, approved for the treatment of relapsed or refractory MM as it has obtained promising results with fast and favourable responses. Unfortunately, as a phase 2 clinical trial of the drug showed (DREAMM 2 trial), up to 70% of patients experienced keratopathy- related adverse events that might require temporary cessation or discontinuation of treatment. 

Four patients (8 eyes) started treatment with Belantamab mafodotin for their refractory MM (recruitment criteria) between March 2021 and November 2021 at a tertiary hospital in Spain. Ocular examination was performed before starting the treatment and every three weeks since then. This examination included: visual acuity and slit -lamp examination, obtaining also photographs and anterior segment coherence tomography (AS-OCT) scans during the follow-up.

One male (25%), 3 female (75%). The average age was 67.5 years, with age ranging from 54 to 77 years. All of them (4/4) have experienced corneal microcyst-like epithelial changes but different grades of severity. Mean follow-up 7.5 months. The longest follow up is 13 months, being this patient the only one who has withheld treament for a 3 months period due to a grade 3 keratopahty. After recovering, the treatment was reintroduced but at a lower dose. In spite of interrupting the treatment, patient´s systemic condition continued in complete remission. Ocular treatment consists on frequent artificial tears, given that topical steroid eyedrops have shown to be ineffective in preventing keratopathy. 

Despite the good results in terms of improving multiple myeloma´s patients quality of life, Belantamab mafodotin causes a non depicable amount of keratopathy-related adverse events. This high rates of ocular adverse effects goes in favour of a tight collaboration between ophthalmologists and hematologists-oncologists in order to get an early diagnosis an treatment of these corneal complications.