Did you know? Dry eye clinical trials face serious hurdles.
Did you know?
In the last 15 years, a slew of dry eye drugs did not get approved by the FDA... for reasons possibly unrelated to whether they actually work.
As noted in the introduction to TFOS DEWS II, the approval of new therapeutic agents for the treatment of DED has been very slow and infrequent. At the time of writing, only two therapeutic drugs, cyclosporine A (indicated for the improved production of tears in those with reduced tear production thought to be due to inflammation) and lifitegrast (indicated for the relief of signs and symptoms of dry eye) have been approved for treatment of DED in the U.S., despite many clinical trials. The exact number of failed trials in this area is not clear, as many have died quietly without fanfare. A similar drug, cyclosporine A with a different formulation, was approved in the European Union (EU) in 2015. There are several approved drugs in Japan, but these have not been approved by the regulatory agencies in most other major countries.
It is possible that the tested yet failed formulations were insufficiently active in controlling the disease. But, what is more likely, is that the design of clinical trials and an incomplete understanding of the disease pathogenesis and development along with regulatory requirements based on earlier understanding of the disease have contributed to the failure rate. The Report of the Inaugural Meeting of the TFOS i2 has a list of failed trials, which utilized corneal staining as a primary endpoint (Table 10) . Recent advances in understanding indicate that corneal staining is a late finding in the development of disease and that it, like most other objective tests, is variable over time owing to the instability of the tear film, a hallmark of DED [6,40].