Shire’s bid to secure US approval for its experimental dry eye disease therapy lifitegrast has hit a bump in the road after regulators issued a complete response letter outlining some additional requests regarding the application following a priority review.

The US Food and Drug Administration has asked for a new clinical study and more information on the drug’s use to treat the signs and symptoms of dry eye disease, one of the most common complaints to eye care professionals for which there remains high unmet medical need. 

However, the firm seems confident of being able to address the issues raised promptly. Shire says it has recently completed a Phase III study of lifitegrast, OPUS-3, that is expected form the basis of its response to the CRL, and that it will also respond to other points raised by the Agency.

Topline results from OPUS-3 are expected before year-end and, if positive, the firm is planning to submit the data as part of a resubmission to the FDA during the first quarter of 2016.

“We will work quickly to address the FDA’s requests related to lifitegrast, as we are committed to delivering a new prescription treatment option for the 29 million adults in the US living with the symptoms of this chronic and progressive disease,” said Philip Vickers, head of Research and Development at Shire.

Shire acquired the drug through its $160-million take-over of US group SARcode Bioscience in 2013, and is expecting peak sales of more than $1 billion if it makes it to market.