The Food and Drug Administration (FDA) has granted Orphan Drug designation to Tesomet (Saniona) for the treatment of Prader-Willi syndrome.

Prader-Willi syndrome is a rare genetic disease characterized by severe hyperphagia that can lead to potentially life-threatening obesity. Tesomet is an investigational fixed-dose combination therapy of tesofensine, a triple monoamine reuptake inhibitor, and metoprolol, a beta-1 selective blocker. 

The designation is supported by results from a phase 2a proof-of-concept study that showed patients treated with Tesomet 0.5mg per day achieved a statistically significant reduction in hyperphagia and a clinically meaningful reduction in body weight. Moreover, an exploratory extension study in adolescents found Tesomet to be safe and well tolerated at lower doses (0.125mg/day and 0.25mg/day) and suggested dose-dependent effects on weight and hyperphagia.

The Company is planning to initiate a phase 2b study of tesomet in PWS in the first half of 2021. Tesomet is also being evaluated for the treatment of hypothalamic obesity; a phase 2b trial will be initiated for this indication in the first half of 2021.

“There is currently no cure for Prader-Willi syndrome and no medicines approved to address the uncontrollable hunger, or hyperphagia, that characterizes this rare disease,” said Rudolf Baumgartner, MD, Chief Medical Officer and Head of Clinical Development at Saniona. “Receiving orphan drug designation will help us advance Tesomet as expeditiously and efficiently as possible.”

The FDA’s Orphan Drug designation is granted to medicines intended to treat or prevent rare diseases or disorders that affect fewer than 200,000 individuals.


Saniona receives U.S. FDA Orphan Drug designation for Tesomet in Prader-Willi Syndrome. [press release]. Waltham, MA: Saniona; March 3, 2021.