The US Court of Appeals has invalidated patent protection for Teva’s multiple sclerosis drug Copaxone for the second time, clearing the way for Novartis unit Sandoz’ and partner Momenta to roll out their copycat Glatopa on the market.

Glatopa became the first Copaxone (glatiramer acetate) generic to win US Food and Drug Administration approval in April - for treating patients with relapsing forms of MS - but the firms held off on a launch while the patent saga was ongoing.

Momenta’s chief executive Craig Wheeler said he is pleased with the decision to invalidate Teva’s process patent, and looks forward “to providing patients with a more affordable generic alternative for the treatment of multiple sclerosis”.

While Teva might not exactly be jumping for joy at the news, Copaxone’s patent protection was due to crumble in September anyway, and the company is working hard to switch as many patients as possible to its longer-acting version of the drug as possible to soften the blow.

Mylan and Natco Pharma have also developed a generic formulation of the blockbuster drug, which pulled in more than $4 billion for Teva last year.