The UK pharma company, which was spun off from Reckitt Benckiser at the end of 2014, is the maker of Suboxone, one of the best-selling treatments for heroin addiction.
It has previously gone down the legal route to protect its prized asset – which accounts for around four-fifths of total sales – with mixed success.
Last June, the firm won a ruling at a federal court in Delaware that meant generic versions of Suboxone won’t be allowed to hit the US market until 2024.
That was only for copycats using a certain formulation though, and Indivior was dealt a huge blow a few months later when US lawmakers ruled that a heroin addiction treatment being made by US giant Dr Reddy’s didn’t infringe on any of Indivior’s patents.
Thursday’s lawsuit has been filed against Teva, Alvogen, Par and Actavis, as well as Dr Reddy’s, all of whom have been involved in litigation with Indivior before.
The FTSE 250 group claims that all of those firms’ proposed Suboxone copycat drugs infringe a patent which was granted by the US Food and Drug Administration only last month.
“We continue to partner with Aquestive Therapeutics to innovate and generate new intellectual property around SUBOXONE Film,” said chief executive Shaun Thaxter.
“We believe this new patent is strong and we are asserting it in order to protect our intellectual property rights.”
Shares rose 0.7% to 401.3p early on Thursday.