The troubled Byetta diabetes drug, which is marketed by Lilly and Amylin Pharmaceuticals, worked better than Merck’s Januvia in trials that measured blood sugar levels after meals in 61 patients who tried each drug for two weeks.

Those taking Byetta had lower blood-sugar levels and ate less food than when they used Januvia, according to the drugmakers, which expect to release the company-sponsored study today at a meeting of the European Association for the Study of Diabetes in Rome.

The results contrast with the dismal news released last month that six patients taking Byetta died of pancreatitis. Amylin maintained there was no evidence to link the drug to the deaths, but Wall Street and doctors have been wary (back story).

“There has been some confusion in the marketplace about the therapeutic differences between Byetta and Januvia,” Ralph DeFronzo, an investigator in the trial and chief of the diabetes division at the University of Texas Health Science Center, says in a statement. “Data from this first head-to-head study showed a clear difference in the method of actions” and short-term effects.

In the US, Byetta prescriptions stalled over the past year at about 50,000 a week, while Januvia scrips jumped almost 50 percent to about 98,000 at the end of August, according to Bloomberg data. Sales of Januvia and Merck’s Janumet more than doubled to $406 million in the last quarter from a year earlier. Byetta is an injection taken twice daily, and Januvia is a once-a-day pill.