The FDA has accepted for review Sandoz’s proposed biosimilar of AbbVie’s blockbuster anti-TNF drug Humira, the company announced yesterday, although if approved the follow-on drug isn’t likely to launch in the U.S. for quite some time.

Pending regulatory clearance, Sandoz (which is the generics and biosimilars division of Novartis) would become the third pharma company to receive an FDA thumbs-up for a Humira biosimilar, following agency green lights on Amgen’s Amjevita in 2016 and Boehringer Ingelheim’s Cytelzo last year.

Despite these approvals, neither Amgen nor BI’s Humira biosimilars—and their presumably lower prices—are available to U.S. patients. That’s because AbbVie has more than 100 patents on the drug. The so-called patent estate was erected to defend Humira’s revenue against competition.

The drug brought in $10.4 billion in U.S. sales in 2016 alone and accounts for the bulk of AbbVie’s revenue. At a presentation to investors at JP Morgan’s annual healthcare conference last week, CEO Richard Gonzalez predicted Humira would generate $21 billion in annual global sales by 2020.

Not to be deterred by the gauntlet of IP protection, AbbVie filed suit against Amgen, and a legal battle between the two was settled last year with Amgen agreeing to withhold sales of Amjevita in the U.S. until 2023. However, the settlement allows Amgen to launch the drug in Europe this fall.

See also: The 2018 pipeline report: Aspiring assets to keep an eye on

Despite the prospect of being third-to-market at best, Sandoz is pressing forward with its Humira filing. The company’s goal is to be able to offer multiple drugs, both biologic and biosimilar, in the disease state. 

“When patients are dealing with a chronic disease, it is imperative they have access to important medication that will help best manage their health,” Mark Levick, Sandoz’s global head of development, biopharmaceuticals, said in a press release. “The FDA’s acceptance of the regulatory submission for our biosimilar adalimumab brings us one step closer to offering a portfolio of options to the millions of patients in the U.S. who suffer from an inflammatory disease.”

See also: Why haven’t biosimilars gained ground in the U.S.?

Indeed, Humira isn’t the only brand-name arthritis drug Novartis is going after. The company has received FDA approval for a biosimilar version of Amgen’s Enbrel anti-TNF drug, and has biosimilars of Johnson & Johnson’s Remicade and Genentech’s Rituxan, two other drugs whose approvals include rheumatoid arthritis, in late-stage testing. 

Meanwhile, Cosentyx—Novartis’ FDA-approved long-acting psoriasis drug—has been forecasted by some analysts to become a blockbuster. Parallel to yesterday’s Sandoz news, Novartis released data showing the drug is superior to J&J’s Stelara in certain measures of the drug’s skin-clearing ability among patients with plaque psoriasis.

A full portfolio of arthritis medications could give Novartis leverage with payers as well as a competitive advantage over rivals with less robust biosimilar offerings.

The adoption of biosimilars in the U.S. has been fairly sluggish, but experts still believe they have the power to significantly lower prices—particularly as competition heats up. There are dozens of potential biosimilar copycats of Humira, Remicade, Enbrel, and Rituxan in various stages of development.

An earlier version of this story incorrectly stated in its fifth paragraph that Amgen filed suit against AbbVie and that the agreement to withhold sales of Amjevita had been made by the court, rather than by the parties to the action.