Sponsors looking to develop drugs to treat dry eye should consider using both traditional environmental exposure and challenge-model trials, according to an FDA draft guidance released last week. Trials where the investigational drug is used as an add-on to a standardized treatment regimen are also acceptable, the guidance says.

Sponsors should conduct separate studies of patients with dry eye secondary to scarring, severe blepharitis or obvious inflammation of the lid margin.

The agency recommends that approximately 400 or more patients complete treatment with the investigational drug, with at least 300 patients completing six weeks of follow-up after the initiation of treatment, and at least 100 patients completing 12 months of follow-up.

Comments on the draft guidance are due March 17.

Read the guidance here: https://bit.ly/3p2ajnd.