Inclusion Criteria: 

• Male or female patients.
• Age ≥ 18 years old at screening.
• Able to provide written informed consent to participate in the trial prior to any trial related procedures are performed.
• Diagnosis of acromegaly by historical evidence of (persistent or recurrent) acromegaly.
• Treatment with a stable dose of octreotide LAR or lanreotide ATG for at least 3 months as monotherapy prior to screening.
• IGF-1 levels ≤ 1 x ULN at screening.
• Adequate liver, pancreatic, renal and bone marrow functions.
• Normal ECG.

Exclusion Criteria:

• GH ≥ 2.5 μg/L at screening (cycle).
• Have received medical treatment for acromegaly with pasireotide (within 6 months prior to screening), pegvisomant (within 3 months prior to screening), dopamine agonists (within 3 months prior to screening) or other investigational agents (within 30 days or 5 half-lives prior to screening [whichever is longer].
• Patients who usually take octreotide LAR or lanreotide ATG less frequently than every 4 weeks (e.g., every 6 weeks or 8 weeks).
• Patients with compression of the optic chiasm causing any visual field defect for whom surgical intervention is indicated.
• Patients who have undergone major surgery/surgical therapy for any cause within 1 month from screening.
• Patients who have undergone pituitary surgery within 6 months prior to screening.
• Patients who have received prior pituitary irradiation.
• Patients with poorly controlled diabetes mellitus (hemoglobin A1c > 8.0%)