Lanreotide, a Somatostatin Analogue, in Advanced Merkel Cell Carcinoma: A Prospective Single-Arm Phase II Study

Merkel Cell Carcinoma (MCC) is a rare, aggressive neuroendocrine and epithelial skin cancer. Somatostatin analogues, such as lanreotide, have shown efficacy in managing other neuroendocrine tumors. Retrospective studies suggest that lanreotide may induce partial response or disease stabilization in patients with advanced MCC. To test this hypothesis, we conducted a Phase II, non-randomized, open trial investigating lanreotide in MCC patients with advanced disease (ClinicalTrials.gov identifier: NCT02351128).

Patients with Stage IIIB-IV MCC received lanreotide monotherapy (120 mg every 28 days) at any line of systemic therapy, until disease progression or unacceptable toxicity. The primary endpoint was disease control rate (DCR) (defined as the proportion of patients with complete response, partial response, and stable disease) at 3 months. Secondary endpoints included progression-free survival (PFS), overall survival (OS), somatostatin receptor (SSTR) tumor expression, and treatment safety.

Between April, 2015, and November, 2016, 35 patients received lanreotide, with 12 evaluable at 3 months. The DCR at 3 months was 33.3% (4) among evaluable patients (all with stable disease) and 11.4% for the full cohort. Statistical analyses showed no significant difference from the expected 20% response rate (p = 0.205 for intention-to-treat; p = 0.939 for per-protocol). Kaplan-Meier analysis revealed median OS and PFS of 3.1 months (95% CI, 2-5.5) and 3.5 months (95% CI, 2.3-5.5), respectively. SSTR tumor expression did not correlate with treatment response.

Although limited by its implementation before the era of immunotherapy, this non-randomized study shows the limited effectiveness of lanreotide as monotherapy in treating patients with advanced MCC.

Identifier: NCT02351128.