US healthcare giant Johnson & Johnson has just been handed its second defeat in patent litigation this month. On Jan. 23, a US appeals court hearing J&J’s challenge to a lower court decision in a lawsuit brought against it by Pfizer subsidiary Hospira ruled that the patent for the arthritis drug Remicade is invalid.

J&J said it plans to appeal the decision, which came a week after the patent office declared the patent for subsidiary Janssen Biotech’s cancer drug Zytiga invalid.

Remicade is J&J’s top-selling drug with sales of $6.3 billion in 2017. In upholding an earlier decision by the US Patent and Trademark Office, the court said the drug, whose patent is due to expire this September, contains antibodies that are already covered by other patents.

Pfizer recently sued J&J for what it said was anticompetitive contracting on Remicade, claiming its rival unfairly protects its brand against biosimilar entrants. It argued in court filings that J&J enters exclusive contracts tying discounts on the existing Remicade patient base to a stipulation that payers don't use biosimilars.

This, Pfizer said, is why sales of Inflectra – a drug its subsidiary Hospira markets for South Korean manufacturer Celltrion –  totaled just $74 million in the US in the first nine months of 2017. In addition to Inflectra, several other biosimilars to Remicade are currently sold on the US market.

Had J&J won the patent appeal, it could have demanded that manufacturers of biosimilars compensate the company for any profits lost to competitors, the news agency Bloomberg reported.