Pfizer is suing Johnson & Johnson (J&J) in the US over what it terms anti-competitive practices against its biosimilar Inflectra. The lawsuit is said to be the first of its kind for biosimilars, which are near-identical copies of biologics - drugs made from living cells rather than chemicals.

Filed in a Pennsylvania court on Sept. 20, the lawsuit alleges that J&J violated federal antitrust laws by signing exclusionary contracts with health insurers to ensure that its blockbuster Remicade was favored over Inflectra.

Both drugs are versions of infliximab and are indicated to treat autoimmune diseases such as rheumatoid arthritis and Crohn’s disease. Remicade, which was approved by the Food and Drug Administration (FDA) in 1998, generated nearly $7 billion in sales for J&J last year.

Pfizer said insurers originally classified Inflectra, which gained FDA approval in April 2016, “at parity” with Remicade, in other words, there was no medical reason to favor one medicine over the other. However, the lawsuit alleges that insurers subsequently did a U-turn and signed “biosimilar-exclusion” contracts after J&J threatened to withhold significant rebates. In addition, J&J is also alleged to have offered discounts on Remicade to those insurers that agreed not to buy biosimilars.

Pfizer said J&J’s actions had resulted in insurers refusing to pay for Inflectra, even though it had an average selling price that was more than 10% lower than Remicade. “It’s not in the best interest of patients and our healthcare system if originator companies like J&J can use their dominant market position to prevent access to lower cost, effective biosimilar medicines in the US,” said John Young, group president of Pfizer Essential Health.

Scott White, president at Janssen Biotech, J&J’s pharmaceuticals unit, said: “We are effectively competing on value and price and to date, Pfizer has failed to demonstrate sufficient value to patients, providers, payers and employers. Competition is bringing down the overall cost of infliximab including Remicade, and will continue to bring down costs in the future. There is no merit to this lawsuit.”

While biosimilars have been hailed as an opportunity to save the US healthcare system billions of dollars on expensive biologic drugs, uptake has been slow. Investment Bank Morgan Stanley said in an April 2017 report that while it believes biosimilars will capture “meaningful” market share, sales to date of much less than $2 billion were disappointing and illustrated that the bar was high. “While we acknowledge that biosimilars could represent a real sales opportunity, we believe that the economics of biosimilars remains challenged," it said.