GlaxoSmithKline’s (NYSE:GSK) former blockbuster diabetes drug Avandia, shackled in recent years by restrictions imposed after studies showed higher health risks, could be on the pathway to getting some of those limitations loosened.

An advisory panel to the Food and Drug Administration on Thursday afternoon voted to modify restrictions on Avandia, a drug that once generated $3 billion a year in revenue for GSK as the company’s top seller. But health concerns emerged in 2007, leading to greater scrutiny of Avandia and calls for stronger restrictions. With the restrictions in place, Avandia was used by only 3,000 people last year and generated just $9.5 million in sales.

Under the current rules, Avandia is limited only to patients who can’t control their diabetes on any other medication. Patients must also sign a waiver stating that they understand Avandia’s risks before they can get a prescription. The FDA imposed those rules in 2010 following hearings on health concerns regarding Avandia. In a separate decision that year, European regulators took Avandia off the market entirely.

A majority of the health experts on the advisory panel said Thursday that limitations on prescribing and taking Avandia should be revisited and regulators should take another look at a GSK study on the drug. Panelists were given four voting choices. The option to modify the restrictions received 13 votes; removing the restrictions received seven votes; and continuing the restrictions received five votes. Just one panelist voted for withdrawing Avandia from the market.

The FDA advisory panel’s Thursday vote is nonbinding but is taken into account as the agency makes its decision. Dr. James Shannon, GSK’s chief medical officer, said that the company will continue to work with the FDA as it considers the recommendations of the committee.

“We continue to believe that Avandia is a safe and effective treatment option for type 2 diabetes when used for the appropriate patient and in accordance with labelling,” Shannon said in a statement issued by GSK following the hearing.

The hearing, which took place Wednesday and Thursday, considered findings from an independent reexamination of GSK’s clinical study of Avandia. The independent study was conducted by the Duke Clinical Research Institute.

The advisers will now discuss what specific changes could be made to the restrictions. Until the FDA makes any changes, the current restrictions on Avandia remain in place.

London-based GSK operates its U.S. headquarters in Research Triangle Park.

(The Associated Press contributed to this report)