Efficacy and Safety of an Octreotide Implant in the Treatment of Patients With Acromegaly

Context: Acromegaly is caused by excessive GH secretion and IGF-I overproduction. The goals of treatment are to reduce GH and IGF-I values to normal and relieve the associated symptoms. Objective: The purpose of this article was to demonstrate that an octreotide implant (84 mg) is safe and efficacious in patients with acromegaly who were responsive to prior monthly octreotide long-acting release (LAR) injections. Design: This was a phase 3, open-label study. Before treatment, subjects received a stable monthly dose of octreotide LAR injections (10−40 mg) for ≥3 months. Randomization was in a 3:1 ratio to either a 6-month octreotide implant or monthly octreotide LAR injections. Setting: This was a multicenter, international study conducted in private or institutional practices. Subjects: Enrollment included 163 subjects (aged ≥18 years) with acromegaly. Main Outcome Measure: The efficacy, safety, and tolerability of the octreotide implant during 24 weeks of treatment was evaluated. Results: After 24 weeks, the success rate of the implant for maintenance of IGF-I and GH levels was 86% (95% confidence interval, 80.3%) compared with a rate of 84% (95% confidence interval, 73.8%) for octreotide LAR. Serum octreotide concentrations after implant insertion increased within 8 days and peaked between days 14 and 28. The overall safety of the octreotide implant and octreotide LAR were similar. Diarrhea and headache were more frequent with the implant, whereas cholecystitis and hypertension were more frequent with octreotide LAR. Conclusions: In this pivotal phase 3 study, the octreotide implant maintained reduced blood levels of GH and IGF-I with continuous octreotide release over 6 months, which was well tolerated.