US Food and Drug Administration approved Xiidra, which is lifitegrast ophthalmic solution 5 %,used to treat dry eye disease. Xiidra is the initial prescription eye drop accepted to treat both the signs and symptoms of dry eye – a group of problems where the tear fluid produced by the eyes is either inadequate to lubricate the eyes appropriately, or of the wrong consistency.
In their statement on July 12th, the US FDA describe that Xiidra “is the initial medication in a new class of drugs, known as lymphocyte function-associated antigen 1 (LFA-1) antagonist.” The medicine binds to a cell surface protein observed on white blood cells.
Manufacturers of Xiidra, Shire US Inc confirmed that two times a day eye drop solution will be brought out during the 3rd quarter of 2016.
If left without treatment, serious forms of dry eye disease can cause pain and result in ulcers or scars on the cornea, the clear tissue at the front of the eye.
Dr. Edward, director of the Office of Antimicrobial Products, FDA Center for Drug Evaluation and Research states,
“Normal tear production is required for clear vision and eye health,”
Dry eye can make it tough to do daily things like use computers, watch TV, or read for prolonged periods. It can also lead to irritation in dry surroundings like as inside airplanes in flight.
Estimates propose around 16 million individuals in the U.S. are diagnosed with dry eye disease, which is more common in women than in men.
The safety and efficacy of Xiidra were evaluated in 4 randomized, controlled studies including over 1,000 dry eye sufferers aged 19-97 years, of whom 76 % were female.
Trial subjects obtained either Xiidra eye drops or placebo eye drops, which they used two times a day for 12 weeks. Outcomes show that in comparison with placebo, therapy with Xiidra showed more improvement in both the signs and the symptoms of dry eye.
A symptom is something that the individual senses or feels – for instance itchiness – that is challenging or not possible to evaluate objectively. A sign is something a person other than the patient can notice – for example redness.
Decrease in signs and symptoms of eye dryness
In the clinical trials, the individuals were evaluated at the start, and then at weeks 2, 6, and 12 for symptoms and signs of dry eye.
Investigators used a patient reported eye dryness score to evaluate symptoms. This revealed a decrease in eye dryness at weeks 6 and 12 in all 4 studies, with enhancements reported at week 2 in two of the studies.
To evaluate signs of dry eye, the researchers used an inferior corneal staining score. 3 of the 4 studies showed a larger decrease in the Xiidra users in comparison with placebo at week 12.
The very common adverse reactions, claimed in 5-25 % of trial subjects were irritation, discomfort or blurred vision, and altered taste sensation (dysgeusia).
The FDA note that dry eye condition is very less common in kids, and the safety and effectiveness of the new medicine has not been examined in sufferers under the age of 17.
Shire note that lifitegrast is a “tiny molecule integrin antagonist that binds to the integrin lymphocyte function associated antigen-1 (LFA-1).” By binding to LFA-1, the medicine blocks its interaction with a molecule known as ICAM-1, a member of a family of molecules that are essential in inflammation.
There have been recommendations that LFA-1/ICAM-1 interaction may lead to a process that activates immune system T-cells and promotes their migration to target tissues. T-cells are believed to be involved in causing inflammation connected with dry eye disease.
However, while in vitro studies have given some additional insights into this circumstantial proof, the manufacturers note that the “specific mechanism of action of lifitegrast in dry eye disease is not known.”