Makers of blood thinner Plavix seek to quash Texas suit

Texas Attorney General Ken Paxton claims that for decades the drugmakers failed to disclose that the medication is less effective in some minority patients, but the companies say the lawsuit is "stale and opportunistic."

by Christina van Waasbergen Court House News,  November 21, 2025

MARSHALL, Texas (CN) — The makers of the blood thinning medication Plavix filed a complaint Friday seeking to block a lawsuit by Texas Attorney General Ken Paxton claiming the companies concealed that the drug is less effective for certain patients.

In a petition filed Thursday, Paxton accuses the companies that manufacture Plavix, Bristol-Myers Squibb and Sanofi, of failing to disclose that the medication is less effective at preventing heart attack and strokes for patients with certain genetic variations that are more prevalent in Black, East Asian and Pacific Islander populations.

The Food and Drug Administration added a black box warning to Plavix’s label in 2010 about the risk of reduced effectiveness in people with genetic variations that affect their ability to metabolize the drug. However, Paxton claims the companies were aware of the risk since at least 1998 and that they failed to warn consumers about it.

“At bottom, defendants prioritized profits even if that meant putting patients’ lives at risk,” Paxton writes in his complaint. “Defendants’ actions were particularly egregious because certain minority patients — Black patients in particular — face disproportionate risk of cardiovascular disease and are twice as likely to die of cardiovascular disease relative to white patients.”

But the companies say Paxton is seeking to cash in due to a $700 million settlement agreement they reached with Hawaii earlier this year after a yearslong legal fight based on similar claims. In a petition filed Friday seeking an injunction blocking Paxton’s suit, Sanofi and Bristol-Myers Squibb say the Texas attorney general is violating their due process rights by bringing a “stale and opportunistic” lawsuit based on claims the state declined to pursue for more than a decade. They also complain about Paxton’s use of private contingency counsel to bring the case.

“When the attorney general investigated the same claims more than a decade ago, without the input of financially interested private counsel, the state decided against moving forward with an enforcement action,” the companies write in their petition. “But now, only after the settlement of a parallel case created the prospect of a financial boon for contingency fee counsel, has the state filed a quasi-criminal enforcement action against the companies. Due process protects the companies from this kind of prosecutorial bias.”

The drug companies also argue Paxton’s suit violates their free speech rights by trying to force them to “parrot” the state’s views on efficacy in patients who metabolize Plavix poorly, on which they say the science is unsettled. Changes the FDA made to Plavix’s label regarding this issue in 2009 and 2010 were “highly controversial,” they say.

“Many leading cardiologists and organizations voiced concern that the newly evolving and mixed science on genetic variability of response did not support the new warnings,” the companies write in their complaint.

Paxton’s office did not immediately respond to a request for comment on Bristol-Myers Squibb and Sanofi’s petition.