An open-label, single-group, multicenter phase II study of lanreotide autogel (LAN) in Japanese patients (pts) with neuroendocrine tumors (NET).

Abstract

471 Background: LAN is a long-acting somatostatin analog indicated in EU for the treatment of carcinoid syndrome and in the US and EU as antiproliferative treatment in pts with gastroenteropancreatic (GEP) -NET. The antitumor efficacy of LAN in pts with GEP-NET was evaluated in the phase III CLARINET study. No study to date has reported the antitumor effects of somatostatin analog in Japanese pts with NET. Methods: In this open-label, single-arm study, Japanese pts with Grade 1 or 2 unresectable metastatic or locally advanced NET received 120 mg once every 4 weeks for 48 weeks. Pts who completed the study were subsequently enrolled in the long-term extension study. The primary endpoint was the clinical benefit rate (CBR: the ratio of pts with a complete response, a partial response (PR), or stable disease over 24 weeks). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR) (RECIST 1.1, central review), serum chromogranin A (CgA) level and quality of life using the EORTC QLQ-C30. The results of the CLARINET study cohort were compared with those from a matched population. Results: 32 pts were recruited in 10 sites. Mean age was 61.7 years. 67.9% were male. The primary tumor sites were pancreas (n = 14), foregut (2), midgut (2), hindgut (8), and unknown (6). Four pts had gastrinoma, and 3 of them had multiple endocrine neoplasia type 1. In the Full Analysis Set (n = 28), 39.3% of pts had progressive disease at baseline according to RECIST criteria. The CBR at 24 weeks was 64.3% (18 of 28 pts) and the median PFS was 36.3 weeks. A PR was confirmed in 1 patient during the 60 weeks of the extension study (ORR: 3.6%). For PFS, the subgroup analysis showed that the results of pts with no progressive disease at baseline or prior treatments for NET were similar to the results of pts in the CLARINET study. LAN decreased serum CgA by at least 50% in 15 of 17 pts (88.2%) who had elevated CgA levels at baseline. Frequent adverse reactions included injection site induration (28.1%), pale stools (18.8%), flatulence (12.5%), and diabetes (12.5%). Conclusions: The efficacy and safety of LAN in this study clearly show that LAN will be a useful treatment option for Japanese pts with NET. Clinical trial information: 132375,142698.