Allergan plc has received an acceptable for filing letter from the US Food and Drug Administration (FDA) for its abbreviated new Drug application (ANDA) seeking approval to market Rifaximin tablets, 550 mg, a generc version of Valeant Pharmaceuticals’ Xifaxan (rifaximin) 550 mg, which is indicated for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults and the reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults.

Based on available information, Allergan believes it is the first applicant”to file an ANDA for the generic version of Xifaxan 550 mg and, should its ANDA be approved, may be entitled to 180 days of generic market exclusivity.

For the 12 months ending December 31, 2015, Xifaxan 550 mg had total US sales of approximately $975 million, according to IMS Health data, and as reported by Allergan.

In company statement, Valeant says it has 22 Orange Book-listed patents covering Xifaxan 550 mg tablets that are scheduled to expire between August 2019 and October 2029. “Valeant is highly confident in its intellectual property rights relating to Xifaxan 550 mg tablets and intends to vigorously enforce such rights in all applicable venues,” said the company in the statement.

Source: Allergan