Roche ($RHHBY) won the FDA's blessing to market a hemoglobin-based diabetes diagnostic, the latest advance in testing for the disease and the first assay of its kind approved in the U.S.

The Tina-quant HbA1cDx assay charts a patient's average blood sugar levels over the past three months by measuring the percentage of hemoglobin A1c bound to glucose. That information allows physicians to better diagnose diabetes and plot its progression as they manage treatment for patients.

The test works on Roche's Cobas Integra 800 platform, and the FDA's sign-off allows the company to start selling the test to clinical labs, making it first in line to cash in on U.S. demand for HbA1c testing. As the agency points out, there are tests FDA-cleared for diabetes monitoring, but Roche's offering is the first approved for diagnosis.

On Roche's heels is Abbott Laboratories ($ABT), which won a CE mark earlier this month for an A1c test of its own, used on the company's Architect diagnostic analyzers. Abbott has filed for FDA approval for the test and is in the meantime rolling it out in in countries across Europe, Asia, Latin America and Africa.

The head start on sales of an in-demand test could well help Roche's flagging diabetes business. While the company's diagnostics arm hauled in $11.2 billion and a 20% share of the global diagnostics market in 2012, Roche has long struggled with pricing pressures and reimbursement cuts for diabetes.

In October, Roche announced plans to cut 100 jobs in diabetes and shift the business' diagnostics division to its Indianapolis headquarters while moving the glucose monitor unit to Germany. Now, according to a Reuters report, Roche is exploring the idea of unloading the meter business, meeting with potential suitors in early-stage talks.