Shares in addiction treatment specialist Indivior (LON:INDV) soared on Monday morning, after announcing a legal breakthrough in the US.

The group’s shares fell by a third last week after it emerged that Indian company Dr Reddy’s Laboratories had been given the green light to sell a generic version of Invidior’s best selling drug.

However, on Monday Indivior confirmed that it had been granted a preliminary injunction against the company, which amounts to a temporary ban on the sale or import of its generic buprenorphine/naloxone sublingual film product.

The news will be welcomed by investors, boosting the group’s share price after a dismal week last week.

“Protecting the integrity of our intellectual property is fundamental to our ability to deliver our vision that all patients around the world have access to evidence-based treatment for addiction and its co-occurring disorders,” said CEO Shaun Thaxter.

Shares in Indivior (LON:INDV) are currently trading up 25.72 percent at 366.10 (1127GMT).