Investigational therapies for acromegaly

The treatment of acromegaly aims at normalizing growth hormone (GH) and insulin-like growth factor (IGF-I) levels and controlling tumor growth. The approaches to therapy are essentially three: surgery and pharmacotherapy, alone or in combination, and radiotherapy, generally used in more aggressive tumors.

This review focuses on the novel drug formulations being developed for medical therapy of acromegaly. Even though many efficient treatments have been made available to manage acromegaly in the last two decades, a significant number of patients remain still uncontrolled. Medical therapy represents an important therapeutic option and can be used as the first-line treatment in many patients. However, roughly 25% of patients might be considered as poor responsive or resistant to conventional long-acting somatostatin analogs (SSA) treatment. Therefore, new longer-acting SSA, oral SSA formulations, new combined therapies with weekly doses of pegvisomant, combination therapy with pegvisomant (PEG) and cabergoline (CAB) or SSA and new approaches have been proposed. New molecules are currently under investigation in clinical trials, such as the SSA multi-receptor ligand, pasireotide, which represents a promising option therapy, especially in patients not adequately controlled with currently available SSA. Further, temozolomide has been suggested as an efficient drug for treating GH-aggressive pituitary tumors resistant to conventional therapy.

All these novel SSA formulations and new molecules implement the available options in therapies of acromegaly to improve disease control. However, further studies are needed to define the exact role of these newer agents. The predicting factors for response to these new therapies should also be determined.