Investigational drugs targeting somatostatin receptors for treatment of acromegaly and neuroendocrine tumors

Introduction: Octreotide long-acting release (LAR) and lanreotide Autogel (ATG) are the two somatostatin analogs currently approved for treatment of acromegaly and neuroendocrine tumors (NETs). The strength of these drugs has been their specificity for somatostatin receptor subtype 2. However, this peculiarity may become a weakness in some patients with tumors harboring somatostatin receptors different from the subtype 2. Another clinically relevant aspect related to the use of octreotide LAR and lanreotide ATG is the burden of injectable drug regimen that may adversely impact the quality of life of patients with acromegaly and NETs. Areas covered: The authors review the recently published evidence on novel drugs targeting somatostatin receptors developed for treating acromegaly and NETs. Within this article, the authors discuss: i) the pharmacology of somatostatin and traditional somatostatin analogs; ii) the efficacy and safety of multireceptor-targeted somatostatin analogs in acromegaly and NETs; iii) the efficacy of chimeric molecules in acromegaly and NETs; iv) the preliminary data on the use of new injectable, oral and transdermal formulations of octreotide in acromegaly. Expert opinion: The development of new somatostatin analogs and new formulations has opened a new scenario for treatment of acromegaly and NETs. That being said, even though there have been big steps taken in the development of new therapies for acromegaly, there are still a number of unresolved issues, while more trials are necessary for the use of somatostatin anaologs in the treatment of NETs.