Drugstores accuse Pfizer, Teva of blocking Effexor generics

CVS Caremark and Rite Aid have signed on to the Effexor XR conspiracy theory. In an antitrust lawsuit, the drugstore chains allege that Pfizer's ($PFE) Wyeth unit and Teva Pharmaceutical Industries ($TEVA) colluded to delay generic versions of the blockbuster antidepressant.

As Reuters points out, it's just the latest accusation of generic-blocking shenanigans boosting sales of Effexor XR, the extended-release version of venlafaxine. Back in December, Walgreen, Kroger, Safeway, Supervalu and HEB Grocery together filed a similar suit against the two drugmakers. Both companies have denied the allegations.

Effexor XR's original patent expired in 2008, but Effexor XR generics didn't make their debut for two years afterward, under a 2006 patent settlement with Teva. CVS and Rite Aid claim that Wyeth extended its exclusivity on the Effexor XR market by obtaining fraudulent patents and suing 17 generics makers for patent infringement, including Teva, Reuters reports.

Wyeth also conspired with Teva to prolong the generics maker's market exclusivity and keep cheaper copycats off the market, the suit claims. Impax ($IPXL) and Mylan ($MYL) both inked deals with Wyeth to introduce their own Effexor XR copycats in June 2011.

The drugstores claim they overpaid for Effexor XR because of the drugmakers' scheming. Effexor XR brought in $2.5 billion a year as long as the generics were delayed, the drugstores say. Since the advent of copycat versions in July 2010, sales have declined; in 2011, Effexor sales were $678 million, a 61% drop from the previous year.

- read the Reuters story