* Retailers said they overpaid for Effexor XR
* Pfizer, Teva have denied claims in similar case
By Jonathan Stempel
June 12 (Reuters) - CVS Caremark Corp and Rite Aid Corp filed an antitrust lawsuit accusing Pfizer Inc and Teva Pharmaceutical Industries Ltd of conspiring to keep generic versions of the popular antidepressant Effexor XR off store shelves.
The lawsuit escalates court battles over alleged delays in the launching of generic versions of Effexor XR. It comes just six months after several other large retailers filed an antitrust lawsuit making similar claims.
In a complaint filed Tuesday with the federal court in Trenton, New Jersey, CVS and Rite Aid accused Pfizer's Wyeth unit of scheming to block generic versions of Effexor XR for at least two years after its marketing rights to the original compound lapsed in June 2008.
They said Wyeth did this by obtaining fraudulent patents, engaging in sham litigation against Teva and 16 other generic drug makers, and scheming with Teva to keep cheaper generic equivalents off the market and prolong Teva's generic exclusivity rights. U.S. sales of Effexor XR topped $2.5 billion annually during this period, they said.
"Plaintiffs have sustained substantial injuries to their business and property in the form of overcharges," the complaint said. CVS and Rite Aid are seeking triple damages and other remedies. Rite Aid's Brooks and Eckert units are also among the plaintiffs.
Pfizer and Teva had no immediate comment. They have rejected the claims in the December lawsuit, which was filed in the same court by Walgreen Co, Kroger Co, Safeway Inc , Supervalu Inc and HEB Grocery Co.
Effexor XR is used to treat depression and anxiety disorders. Its chemical name is venlafaxine hydrochloride.
Pfizer's global sales of Effexor XR totaled $129 million from January to March. Sales fell 37 percent from a year earlier and have been declining because of generic competition.
Pfizer is based in New York; Wyeth has operations in Madison, New Jersey; and Israel-based Teva has U.S. operations in North Wales, Pennsylvania. CVS is based in Woonsocket, Rhode Island, and Rite Aid in Camp Hill, Pennsylvania.
The case is Rite Aid Corp et al. v. Wyeth Inc et al, U.S. District Court, District of New Jersey, No. 12-03523.