Introduction: Long-acting repeatable (LAR) octreotide i.m. is a potent, synthetic somatostatin analogue (SSA) that requires less frequent dosing and offers quality of life (QoL) benefits in acromegaly patients compared to its shorter-acting predecessor. This study investigated the efficacy and safety of high-dose Sandostatin® LAR® as monotherapy or in combination with pegvisomant or cabergoline in acromegalic patients with pituitary adenomas following previous failure of conventional SSA treatment.
Material and methods: After three months of high-dose Sandostatin® LAR® monotherapy (40 mg), patients who achieved biochemical control (n = 7) continued to receive the same treatment for an additional four months, whereas uncontrolled patients were randomised to receive high-dose Sandostatin® LAR® in combination with pegvisomant (n = 31) or cabergoline (n = 32). Outcomes included biochemical response at eight months, QoL, and safety.
Results: After three months, 3 of 68 (4.4%) evaluable patients achieved a biochemical control (BC) as assessed by levels of growth hormone and insulin-like growth factor-1. At eight months, 4 of 67 (6.0%) patients achieved BC, including one receiving monotherapy and three receiving Sandostatin® LAR® plus cabergoline. Partial response rate, improvements in acromegaly signs and symptoms, and changes in QoL were similar for all three groups. All treatments were well tolerated with a slight excess of adverse events in the combination arms. There were no deaths or serious adverse events leading to treatment discontinuation.
Conclusion: These data demonstrate that high-dose Sandostatin® LAR® as monotherapy or in combination with pegvisomant or cabergoline is a feasible salvage option in patients with pituitary adenomas not adequately controlled on conventional SSA regimens.
Keywords: acromegaly; cabergoline; combination; monotherapy; octreotide LAR; pegvisomant.