Background Lanreotide autogel is a somatostatin analog (SSA) approved for the treatment of acromegaly in 73 countries worldwide; however, it is not yet approved in China. The aim of this study was to evaluate the efficacy and safety of lanreotide autogel compared with lanreotide 40 mg prolonged release (PR) in Chinese patients with active acromegaly. Methods LANTERN was a phase 3, randomized, open-label, non-inferiority study. Patients with active acromegaly who had undergone surgery >= 3 months prior, or were unlikely or unable to undergo surgery, were treated with lanreotide autogel 60/90/120 mg (monthly deep subcutaneous injection) or lanreotide 40 mg PR (intramuscular injection every 7, 10, or 14 days) for 32 weeks. Primary endpoint was mean change-from-baseline in age-adjusted insulin-like growth factor-1 (IGF-1) standard deviation scores (SDS) at the end-of-study. Secondary endpoints included: growth hormone (GH) levels <= 2.5 mu g/L or <= 1.0 mu g/L, >= 20% reduction in tumor volume (TV) and safety. Results In total, 128 patients were randomized and received study treatment. Lanreotide autogel was non-inferior to lanreotide 40 mg PR: treatment difference (95% CI) for IGF-1 SDS between groups was - 0.32 (- 0.74, 0.11; per protocol population) and - 0.27 (- 0.63, 0.09; intention-to-treat [ITT] population), respectively. Reductions in IGF-1 (- 6.453 vs - 7.003) and GH levels (- 9.548 mu g/L vs - 13.182 mu g/L), and the proportion of patients with >= 1 acromegaly symptom (- 20.3% vs - 32.5%) were observed from baseline to end-of-study in lanreotide autogel and lanreotide 40 mg PR groups, respectively. In the lanreotide autogel group, 45.5% (25/55) patients achieved >= 20% reduction in TV compared with 50.9% (25/53) in lanreotide 40 mg PR group (ITT). Safety profiles were similar in both treatment groups. Conclusions Lanreotide autogel was non-inferior to lanreotide 40 mg PR in Chinese patients with active acromegaly after 32 weeks of treatment.