US pharmaceutical giant Pfizer said Tuesday that it would begin selling a Remicade biosimilar developed by South Korean biopharma company Celltrion in the US from late November.

Pfizer plans to offer Inflectra, a biosimilar drug referencing Johnson & Johnson’s blockbuster autoimmune disease drug Remicade, at a price that is 15 percent lower than the original drug. It is the first Remicade biosimilar to go on sale in the US.

Pfizer currently holds exclusive rights to commercialize Celltrion’s Remicade biosimilar in select markets, including the US and Canada through a sales partnership between Pfizer-owned Hospira and Celltrion.

Biosimilars refer to cheaper, near-replicas of biologic drugs that have lost patent protection. Inflectra, already sold under the name Remsima in other regions, is expected to eat into the US-based sales of Remicade, J&Js’ top-selling drug which raked in $6.6 billion in worldwide sales last year.

“By introducing Inflectra to the US marketplace, Pfizer is helping customers access an additional high quality treatment option that promises greater savings for the health care system,” said Diem Nguyen, North America regional president of Pfizer Essential Health Business.

Though on track to launch Inflectra next month, Pfizer is still engaged in a legal dispute with J&J in the US over patents involving Remicade, though the latest rulings have favored Pfizer and the new biosimilar drug.

A US district court ruled in August that Inflectra did not infringe on Remicade’s formulation patent held by J&J subsidiary Janssen, which expires in 2018. The decision had reaffirmed a previous decision by the US Patent & Trade Office which invalidated Janssen’s 471 Patent.

A separate hearing to discern the validity of Janssen’s other remaining patent — the 083 Patent involving Remicade’s cell culture composition, which Janssen says expires in 2027 — is pending. The case is likely to reach a conclusion in February next year, according to Celltrion.

“Pfizer and Celltrion’s legal team have been carefully preparing Inflectra’s US launch. We do not expect more legal hurdles will stand in the way of Inflectra’s launch in the future,” a Celltrion spokesperson told The Korea Herald.

Meanwhile, J&J vowed to “defend our intellectual property rights” and to “compete through a variety of innovative contracting options” in a statement to the Wall Street Journal.

J&J also highlighted Remicade’s “well-established profile” built over 22 years of use in 2.6 million patients and noted that Inflectra cannot be automatically substituted for Remicade.

Shares of Kosdaq-traded Celltrion soared 7 percent on Tuesday to close at 107,000 won ($94.03) on rosy expectations for Inflectra’s sales in the US.

By Sohn Ji-young (jys@heraldcorp.com)