WASHINGTON -- The FDA has sanctioned use of gastric banding for weight-loss surgery in a wider range of patients -- those with BMIs of 30 or more, rather than a minimum BMI of 35.

The FDA approved Allergan's Lap-Band System for adults with a BMI of 30 to 40 and at least one obesity-related comorbidity, such as diabetes.

Patients also must have tried and failed more conservative weight-loss therapies such as diet, exercise, and weight-loss medications.

According to a company press release, some 37 million Americans will be covered by the expanded indication. The product was previously approved for a narrower range of individuals: those with BMI of 40 or more, BMI of 35 or more with at least one comorbid condition, or at least 100 pounds of excess weight irrespective of BMI.

The approval to reduce the BMI threshold was based on the FDA review of 12- and 24- month data from a prospective, single-arm, multicenter study with five years of follow-up.

The company said it planned to follow study participants for an additional five years as part of its postmarketing surveillance.

Additionally, "there will be an analysis of the outcomes of patients with BMI of 30 to 40 recorded in the Bariatric Outcomes Longitudinal Database," the company said.

The lap-band study, which was initiated and supported by Allergan, recruited 149 patients who had a mean excess weight of 62.8 lbs and had been obese on average for 17 years. All 149 underwent the LAP-BAND System procedure.

The primary endpoint was clinically meaningful weight loss at one year. The trial stipulated that at least 40% of the patients needed to achieve that endpoint.

Clinically meaningful weight loss "was defined as at least 30% Excess Weight Loss (EWL)" meaning a weight loss equal to at least 30% of the difference between the patient's normal weight and his or her baseline weight.

Allergan said that "83.9% of the patients lost at least 30% of their excess weight at the one-year timepoint, more than twice the percentage required for success. More than 65% of the patients in the trial were no longer obese after one year. Weight loss was maintained in the second year of the study."

The secondary endpoints for the trial were improvement in obesity-related conditions including dyslipidemia, type 2 diabetes, and hypertension, as well as improved quality of life.

About a third of patients with the comorbid conditions "saw their conditions resolved after one year," according to the company.

An FDA advisory panel determined by a vote of 8 to 2 in December that the product was adequately safe for the indication sought by Allergan. It also voted 8 to 1 that it was effective.