Tumor response in the CLARINET study of lanreotide depot vs. placebo in patients with metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

Abstract

434 Background: In the CLARINET study, significant improvement in progression-free survival (primary endpoint) was reported in patients (pts) treated with lanreotide depot (LAN), a long-acting somatostatin analog, for moderately- or well-differentiated, nonfunctioning, locally advanced or metastatic GEP-NETs. A favorable safety profile was also observed. This retrospective analysis presents tumor response from CLARINET. Methods: Pts were randomized to LAN 120 mg (n=101) or PBO (n=103) once every 28 days for 96 weeks. Tumor response was evaluated centrally using RECIST version 1.0. Pts’ tumors were measured by sum of the longest diameter (SLD) of target lesions (TLs). Change was calculated for each pt’s SLD from baseline to last available post-baseline assessment. Tumor response was classified as complete response (CR): disappearance of all TLs and non-target lesions (NTLs) and no new lesions; partial response (PR): ≥30% decrease in SDL and no progressive disease (PD); stable disease (SD): not meeting criteria for CR/PR or PD; PD: ≥20% increase in SLD from baseline or nadir, unequivocal progression of NTLs or appearance of new lesions. The remaining pts were not evaluable (NE) for response. Results: 101 pts treated with LAN and 103 pts treated with PBO were assessed for tumor response. Among pts receiving LAN, 64% (65/101) demonstrated SD compared to 43% (44/103) of pts receiving PBO (Table). An additional 2 pts in the LAN group achieved a PR. Similar trends were observed in pts with pancreas and midgut origin tumors. Conclusions: A clinical benefit (defined as CR+PR+SD) of 66% (67/101) was observed with single agent LAN vs 43% (44/103) with PBO in the CLARINET population, further supporting the clinical efficacy of LAN. Clinical trial information: NCT00353496. [Table: see text]