Can someone with more familiarity with the FDA approval process explain further?  Can AstraZeneca refuse to strengthen the warning?

Jan. 27 (Bloomberg) -- AstraZeneca Plc was asked by U.S. regulators to strengthen warnings on its antipsychotic drug Seroquel about potential side effects that can lead to diabetes, according to court documents.

The U.S. Food and Drug Administration wants AstraZeneca, the U.K.’s second-largest drugmaker, to highlight on Seroquel’s warning label that some users experienced “significant weight gain,” lawyers for consumers suing the company said in a court filing yesterday. The first trial over claims that Seroquel caused diabetes is set to begin Feb. 2 in Orlando, Florida.

Source: Bloomberg.com: News