With billions at stake, will biosims finally make a mark in the U.S. in 2017?

Biosimilars have already taken hold in Europe, with Celltrion's Remicade copy, for one, wreaking havoc on the branded med's sales. Whether they'll finally make their mark in the U.S., though, remains to be seen—and 2017 could be the year we find out.

Over the next several years, billions of dollars in legacy drug sales could be ceded to an oncoming and rising wave of biosimilars, with much of the action set to kick off in 2017. All told, 7 of biopharma’s top 10 best-selling drugs next year face a near-term biosim threat, meaning fortunes will be made or lost as the field continues to take shape.

Pfizer, for its part, is hoping to repeat partner Celltrion's success at home with its U.S.-approved copy of Johnson & Jonnson's inflammatory blockbuster. The New York pharma has introduced Remicade biosimilar Inflectra in the U.S. at a 15% discount to its reference product, and with the launch, Pfizer will focus on healthcare providers over patients so that docs can help people make informed decisions on whether to start with the biosim or switch from Remicade, a regional exec recently told FiercePharma. Bernstein analysts recently predicted the Pfizer version will be slow to pick up share in the first half of 2017, but that the launch will “accelerate” in the second half.

Another rollout to continue in the U.S. in 2017 is Eli Lilly and Boehringer Ingelheim’s just-launched Basaglar, a biosimilar of Sanofi’s big-selling basal insulin Lantus. Together, Lilly and Boehringer will work to target €4.02 billion in annual U.S. sales for a Sanofi med that’s already been hurting from payer pressure. Further competition could impact that market, as well, as Merck has its own Lantus biosim in the works.

Success of those newcomers will depend on how quickly doctors and patients jump onboard the biosim train, and that rate could pick up as more products join Novartis' Zarxio, a copy of Amgen's Neupogen that until recently was the only marketed biosim in the U.S. Payers eager for cost savings may do their part to help speed things along; CVS Health has already announced that it'll be replacing Lantus with Basaglar on its 2017 formulary.

On the other hand, though, marketing biosims against entrenched rivals will likely prove challenging as new entrants will need to compete with established payer relationships and hefty patient assistance programs.

Fundamental legal questions also remain surrounding biosims in the U.S., though, Bernstein analyst Ronny Gal pointed out in a recent note, including “whether the biosimilar pathway will survive” a potential Affordable Care Act repeal. Plus, he said, the Supreme Court will likely review the “patent dance clauses which are currently optional.” That could potentially throw a wrench in future launches.

On the flip side, in Europe, the biosimilar “market dynamics are getting pretty clear,” Gal wrote, predicting that the continent will see a “watershed year for biosimilars” in 2017. There, Gal and other Bernstein analysts said, the success of biosims against Amgen’s Enbrel and Merck’s Remicade are a “foregone conclusion in our mind.”

Celltrion’s Remsima has already been taking a toll on branded revenue for Remicade, dragging European sales for the med down 26% in the most recent quarter. Bernstein analysts said the biosim is set to grab more than half the European market by the end of next year. Biosimilars going up against Amgen’s Enbrel are expected to grab a third of the market on the continent in the upcoming year, too, the analysts said.

But by far the biggest biosimilar target on either side of the pond is AbbVie’s Humira, for which Amgen has a U.S.-approved copy awaiting launch. Following that biosim’s FDA approval, AbbVie quickly slapped Amgen with a patent suit, citing “blatant infringement.” Analysts have said Humira could see biosim competition as early as 2018. EvaluatePharma predicts $17.6 billion in sales for Humira next year.