Shire’s bid to stay independent as it fends off AbbVie’s advances has been boosted by the news that a US court has backed the firm’s patents on its big-selling attention-deficit hyperactivity disorder drug Vyvanse.

The court in New Jersey granted Shire’s summary judgment motion in a patent infringement lawsuit that certain claims of the patents protecting Vyvanse (lisdexamfetamine dimesylate) were both infringed and valid. The ruling prevents the five  manufacturers who have filed Abbreviated New Drug Applications - Actavis, Amneal, Mylan, Roxane and Sandoz - from launching generic versions until the expiration of these patents in 2023.

The five can appeal the decision but would need to overturn the court’s rulings for each of 18 patent claims. Furthermore, following a request by the US Food and Drug Administration, Shire is to conduct trials of Vyvanse for ADHD in preschool-age children, and will be entitled to a six-month extension  of exclusivity.

Earlier this week, Shire stressed the importance of Vyvanse, which had sales in the fourth quarter of $329.9 million, to reaching its target of doubling group revenues to $10 billion by 2020. The Ireland-domiciled group made a presentation to analysts after it rejected AbbVie’s unsolicited $46.4 billion and noted that it plans to file Vyvanse in the USA, under the codename LDX, for binge-eating disorder in the third quarter.