Evaluation of interferon-alpha 2b as a treatment for ocular squamous cell carcinoma in the horse

Squamous cell carcinoma is the most common tumor of the eye and associated structures in the horse. The goal of this study is to determine if injection and/or topical solution of a human drug (interferon-alpha 2-beta, IFN-α2b) can safely lead to cure (remission) or significantly decrease the size of ocular surface squamous neoplasia (OSSN) in the standing horse.

The purpose of this study is to determine the ability of injections of IFN-α2b into the conjunctival portion of OSSN and topical IFN-α2b for the corneal portion of OSSN to decrease the size of the tumors in horses. The injection procedure will be performed in the horse standing with mild sedation every two weeks for a total of three injections. Topical IFN-α2b medication will be sent home to use three times a day in the affected eye. Horses must have a biopsy or cytology confirmation of OSSN to enter the study.

Treatment is provided at no cost as well as complete physical and ophthalmic exams performed at each visit and initial blood work to assess general health.


ocular squamous cell carcinoma

eligibility information

Horses must be in good general health and have confirmation of squamous cell carcinoma, or ocular surface squamous neoplasia, of the globe via biopsy or cytology.

The initial exam and biopsy/cytology are requirements to enroll in the study and are not covered by the study.

Enrollment Deadline

Enrollment ends April 1, 2023

contact information

Clients who feel their horse may qualify for the study and want to set up an initial appointment may contact Dr. Kathryn Wotman (primary investigator) at kathryn.wotman@colostate.edu or contact the ophthalmology service at cvmbs-vth_ophtho@mail.colostate.edu.