Abstract CT115: Efficacy of surufatinib in Western patients with pancreatic neuroendocrine tumors

Introduction: Recently reported results from the SANET-ep study (NCT02588170) demonstrated superior efficacy of surufatinib (S) in Chinese patients (pts) with advanced extra-pancreatic neuroendocrine tumors (epNET) when compared to placebo (median progression free survival 9.2 vs. 3.8 months). S is an inhibitor of tyrosine kinases VEGFR1, 2, and 3, FGFR1, and CSF-1R. Trials in the US are ongoing, however genetic differences leading to disparate metabolism of S in different pt populations are unknown. We report a comparison of PK and safety across populations treated with S. Methods: A phase I/II study of S, (NCT02267967), conducted in Chinese pts, and a similar study, (NCT02549937), conducted in US pts are compared to evaluate potential effects of race to surufatinib exposure. Both trials enrolled pts at the recommended phase 2 dose (RP2D) of 300 mg QD in three tumor types including Biliary Tract Cancer, epNET, and pancreatic neuroendocrine tumors (pNET). Results: PK sampling was obtained on days 1 and 14 in 81 Chinese pts, and on days 1, 8, 15, and 29, in 39 US pts. Out of 39 US pts there were 29 Caucasian, 2 Asian, and 8 were not reported. Following a single dose of S 300 mg on day 1, geometric mean (percent coefficient of variation of geometric mean, %CV) Cmax and AUCtau were 376 (70%) ng/mL and 2770 (56%) hr*ng/mL, respectively, in Chinese pts, compared to 354 (61%) ng/mL and 3050 (56%) hr*ng/mL, respectively, in US pts. Following S to steady-state on day 14/15, Cmax and AUCtau were 487 (65%) ng/mL and 4810 (58%) hr*ng/mL, respectively, in Chinese pts, compared to 471 (59%) ng/mL and 5130 (50%) hr*ng/mL, respectively, in US pts. PK exposures on days 15 and 29 were similar. In 81 Chinese pts, 100% of pts experienced a treatment-related adverse event (TRAE), and 79.5% of 39 US pts reported a TRAE. The most common TRAEs reported were proteinuria (81% and 12.8%), diarrhea (72% and 23.1%), and hypertension (60% and 35.9%) in Chinese and US pts respectively. The most commonly reported ≥ Grade 3 TRAE9s were: hypertension (33% and 23.1%), proteinuria (12% and 2.6%) and diarrhea (6% and 7.7%), in Chinese and US pts, respectively. Serious adverse events were reported in 27% of Chinese pts and 23.7% of US pts. The safety profile in the two populations appear to be similar at the RP2D. In addition to a similar toxicity profile, the relative dose intensity in both trials were comparable. In Chinese and US pts, respectively, the relative mean dose intensity was 90%, and 84%, and the median intensity was 97% and 96%. Conclusions Given the similar PK and toxicity profiles of S between Chinese and US pts, it can be concluded that race has minimal effect on S exposure. Further evaluations of safety and efficacy are being conducted in ongoing global studies. Citation Format: John Kauh. Efficacy of surufatinib in Western patients with pancreatic neuroendocrine tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT115.