Amgen Sues Rival Over New Wonder Drug

Biotechnology giant Amgen Inc. filed a lawsuit on Friday against Chugai Pharmaceutical Co. that effectively seeks to establish a monopoly for Amgen on its next blockbuster drug.

The suit, filed in U.S. District Court for the District of Columbia, seeks a judgment that Amgen’s patent on the drug does not infringe on two Chugai patents and declares Chugai’s patents invalid and unenforceable.

The patents are for genetically engineered versions of granulocyte colony-stimulating factor (G-CSF), which trigger production of white blood cells, one of the body’s key infection fighters. G-CSF is expected to help quell a variety of infections in cancer chemotherapy patients. Amgen, based in Thousand Oaks, began selling G-CSF last year, and its sales of the drug are expected to total more than $100 million in its first year.

The potential market for G-CSF is estimated by analysts at up to $800 million a year.

Chugai, a Japanese concern, was awarded two U.S. patents for G-CSF last year, but has not begun selling the drug yet. Chugai officials could not be reached late Friday.

Amgen’s suit “is a preemptive strike to prevent a competitor from entering a market that is now a monopoly for them,” said analyst Brandon Fradd at Montgomery Securities.

Another Amgen rival, Immunex Corp. in Seattle, sells a drug that is similar to G-CSF, but Amgen’s drug has been far outselling the Immunex drug.

In its complaint against Chugai, Amgen also alleged violation of federal racketeering laws and fraud, but it was unclear what those allegations referred to.

Amgen officials declined to comment on the suit or any damages it might seek.