The Use Of Brimonidine To Prevent Corneal Toxicity Caused By The Systemic Cancer Treatment Mirvetuximab Soravtansine.

We describe the use of brimonidine eyedrops (Alphagan®, Allergan) as a preventive measure for corneal toxicity caused by the experimental cancer treatment, mirvetuximab soravtansine. The use of brimonidine has not been described before as a preventive measure for mirvetuximab soravtansine-associated corneal toxicity.

A 57-year-old female with ovarian cancer was treated with mirvetuximab soravtansine in a phase III study in the University Hospital Leuven, Belgium. After 6 weeks of treatment, she presented with blurred vision in both eyes. Biomicroscopy showed fine cystic corneal subepithelial opacities. Best corrected visual acuity (BCVA) was 0.8 in the right eye and 1.0 in the left eye. These symptoms occurred despite the preventive steroid eye drops as described in the study protocol.

Brimonidine eye drops were administered in the right eye, 10 minutes before administration of the systemic treatment. The fixed schedule of corticosteroid eye drops was continued as before. Due to a favorable response in the right eye, brimonidine was given in both eyes with the next systemic treatment. BCVA, biomicroscopy and Pentacam topographic examination were followed up closely in the following weeks.

There was a subjective decrease in blurred vision. Pentacam topography showed a diminution in total corneal densitometry in the right eye from 26.5 to 23.8. After administering brimonidine in the both eyes before treatment, the left eye also showed a good diminution in densitometry from 26.1 to 24.7. The mechanism of this effect is probably caused by the vasoconstrictive effect of brimonidine, which is a selective alpha2-adrenergic receptor agonist. Because of the vasoconstriction, it is more difficult for the systemic treatment to penetrate the structures of the eye and this way corneal toxicity could be diminished. 

This case suggests that brimonidine eye drops could prevent or diminish the corneal toxicity caused by the systemic cancer treatment mirvetuximab soravtansine. Prospective clinical research is necessary to confirm this effect in other patients. The use of brimonidine in this context could possibly lessen the burden of these cancer patients.