GlaxoSmithKline has said it now has sufficient supplies of its diabetes product Avandamet to officially re-launch the drug in the USA once again.

The company made the statement shortly after the US Food and Drug Administration cleared Avandamet (rosiglitazone and metformin) as a first-line treatment for diabetes, broadening its use from its earlier second-line status in patients who could not control their blood sugar levels using metformin alone.

Along with its sister product Avandia (rosiglitazone), Avandamet brought £1.3 billion ($2.4bn) into GSK's coffers in 2005, despite the latter having been subject to supply constraints – relating to manufacturing compliance issues at a plant in Puerto Rico - that led it to be temporarily removed from the market.

Broader use of Avandamet, along with the launch of another combination product Avandaryl (rosiglitazone plus glimepiride) is expected to drive sales of the franchise to more than $2.8 billion this year, according to analysts.

“Avandamet is the only combination of a thiazolidinedione and metformin HCl, with approved use as initial therapy of type 2 diabetes,” said GSK in a statement. Rival product ActoPlus Met (pioglitazone and metformin) from Takeda has not yet won approval for front-line use.