(Reuters) – Independent advisers to the U.S. Food and Drug Administration on Friday voted unanimously in favor of Horizon Therapeutics Plc’s experimental treatment for active thyroid eye disease, taking the drug closer towards potential approval.

If approved, teprotumumab, a type of immunotherapy, is expected to become a standard of care for the vision-threatening autoimmune disorder, which currently has no approved therapies.

The panel voted 12-0, when asked if the treatment’s benefits outweighed its risks considering it caters to an unmet need.

Thyroid eye disease usually occurs in people with Graves’ disease, an immune system disorder that results in overproduction of thyroid hormones. TED begins with an active phase that may last for up to three years, after which damage to the eyes can be irreversible.

With the FDA’s blessing, Horizon will be able to tap into a market with an estimated 15,000 to 20,000 patients suffering from moderate to severe forms of the disease.

The addition of teprotumumab, which analysts expect could bring in U.S. sales of over $700 million at peak, is expected to expand Horizon’s best-performing unit that made up nearly three-quarters of its revenue in the latest reported quarter.

The unit focuses on treatments for rare conditions.

Ahead of the voting on Friday, the panel raised concerns about the small size of the sample in the trial, and side-effects including loss of hearing, muscle spasms, diarrhea, infections and possible risks for diabetic patients.

These safety concerns, the panel agreed, need to be addressed in the labeling of the treatment.

“I understand the risks and that there should be post approval follow up, but the benefits so far outweigh the risks and I would say 90% would take the risk than live with the symptoms,” said Jennifer Schwartzott, the patient representative on the panel.

As thyroid eye disease progresses it causes double vision, bulging of the eye and misalignment severely affecting the quality of life of patients.

The FDA is expected to make a final decision on the treatment’s approval by March 8, 2020. While the agency is not bound to follow the recommendation of its advisory panels, it usually does so.

(Reporting by Vishwadha Chander and Manojna Maddipatla in Bengaluru; Editing by Maju Samuel and Shailesh Kuber)