Novel beta3 adrenergic receptor ligands: a patent review

INTRODUCTION: Stimulation of the β(3)-adrenoceptor (β(3)-AR) is thought to be a valuable approach for the treatment of obesity, type 2 diabetes, heart failure, frequent urination, preterm labor, anxiety and depression. Therefore, the β(3)-AR is recognized as an attractive target for drug discovery. Simultaneous activation of the β(1)- and β(2)-AR can cause undesirable side effects such as increased heart rate and muscle tremors. Consequently, much effort has been directed towards the design and development of selective β(3)-AR agonists through original synthetic chemistry, extensive in vitro tests and detailed preclinical investigations to various phases of clinical trials. AREAS COVERED: SciFinder Scholar, PubMed, ISI web of Knowledge(SM), Espacenet, ClinicalTrials and Google have been used as the main sources for retrieving literature and patents filed since the discovery of β(3)-AR through to June 2010. This review discusses the enormous efforts made by private and public research laboratories to uncover β(3)-AR ligands and to prove their usefulness as drugs. EXPERT OPINION: Remarkable knowledge has been gained about the physio-pathological role of the β(3)-AR to date. Many highly potent and selective β(3)-AR ligands (agonists, antagonists and inverse agonists) have been discovered; however, further investigations are still needed to identify novel compounds acting as β(3)-AR ligands in order to adequately treat the diseases in which β(3)-AR is involved.