On March 19^th, 2014, Hawaii Attorney General David M. Louie filed suit against the manufacturers of the popular drug Plavix^®. Louie claims that the manufacturers knew and did not disclose that the medication would be ineffective or only partially effective in certain patient populations due to genetic variations. Plavix is metabolized by the drug-processing enzyme CYP2C19. Certain genetic variations can affect the activity of this enzyme. Patients with these variations are at a higher risk of treatment failure or adverse drug events, even on a normal dose.

Hawaiians would be especially vulnerable to treatment failures due to the state’s ethnic makeup. It’s estimated that between 38-79% of Pacific Islanders and 40-50% of East Asians would have these variations. These two ethnicities together made up 48.6% of the Hawaiian population according to the 2010 census.

The FDA added a boxed warning to Plavix in 2010, which warned about diminished efficacy in poor metabolizers, however, the Hawaii Attorney General alleges that Bristol-Myers Squibb and Sanofi-Aventis, Plavix’s manufacturers, knew about the risk as early as 1998 and failed to inform the public. He is seeking $10,000 for each deceptive or unfair act, plus an additional $10,000 for each act directed towards the elderly, as well as the disgorgement of $10 million in profits from Plavix sales in Hawaii.

Plavix is a common medication prescribed to prevent blood clots. It’s estimated that 115 million patients take the prescription worldwide with 50 million inside the United States. Plavix sales were worth $6.6 billion in 2011. Hawaii is the fifth state to sue the manufacturers of Plavix. California, Louisiana, Mississippi and West Virginia have also filed their own lawsuits. The manufacturers have declined to comment on the lawsuit. The U.S. Department of Justice is also now investigating.

Whether or not these lawsuits are successful in the courts, this may signal the beginning of a sea-change in the way drug manufacturers create and market their medications. The public has shown a greater interest in individualized therapies and a reaction against block buster development. According to the New England Healthcare Institute, adverse drug events may cost US healthcare system nearly $300 billion each year. Better development practices on the part of manufacturers may help alleviate some of that burden.