TAS-116, an oral HSP90 inhibitor, in combination with nivolumab in patients with colorectal cancer and other solid tumors: An open-label, dose-finding, and expansion phase Ib trial (EPOC1704)

Autor: Yasutoshi Kuboki, Miki Fukutani, Daisuke Kotani, Hiroyoshi Nishikawa, Kenichi Harano, Noboru Yamamoto, Hikari Shima, Mitsuko Suzuki, Masashi Wakabayashi, Kohei Shitara, Tsukiko Higuchi, Akihiro Sato, Yoichi Naito, Akihito Kawazoe, Shogo Nomura, Hiroya Taniguchi
Rok vydání: 2020
Předmět:
Zdroj: Journal of Clinical Oncology. 38:4044-4044
ISSN: 1527-7755
0732-183X
DOI: 10.1200/jco.2020.38.15_suppl.4044
Popis: 4044 Background: Regulatory T cells (Tregs) potentially induce the resistance of anti-PD1/PD-L1 inhibitors (A-PD1). TAS-116, a novel HSP90 inhibitor, enhanced antitumor immunity via reducing Tregs in vitro and in vivo. Combination of TAS-116 plus A-PD1 showed a superior tumor growth suppression compared with either treatment alone in vivo. Based on the above, we investigated safety and efficacy of TAS-116 in combination with nivolumab in patients with solid tumors. Methods: Enrolled patients received TAS-116 plus nivolumab in a dose-finding part to estimate the maximum tolerated dose and the recommended phase 2 dose (RP2D). Additional patients were enrolled in a dose-expansion part. TAS-116 monotherapy (orally once daily, 80mg on level 1, 120mg on level 2, and 160mg on level 3) was administrated for 2 weeks followed by the combination with nivolumab (intravenously every 2 weeks, 3 mg/kg). The primary endpoint was dose-limiting toxicities (DLTs) during the first cycle (4 weeks). PD-L1 combined positive score (CPS) and tumor mutation burden (TMB) were assessed. We also conducted biomarker research using paired samples from repeated tumor biopsies and blood collections. Results: A total of 44 patients with colorectal cancer (CRC, n = 29), gastric cancer (GC, n = 8), sarcoma (n = 5), non-small cell lung cancer (NSCLC, n = 1) and melanoma (n = 1) after standard of cares were enrolled. One patient had MSI-H CRC, but all other patients had MSS tumors. No DLTs were observed at all levels and TAS-116 160 mg was determined as RP2D. The common grade 3 or worse treatment-related adverse included AST/ALT increased (7%), creatinine increased (5%) and platelet count decreased (5%). Objective tumor response was observed in 6 patients including 4 MSS CRC, 1 MSI-H CRC and 1 sarcoma, resulting in objective response rate (ORR) of 16% in MSS CRC without prior A-PD-1. PD-L1 CPS and TMB could be evaluated in 18 and 17 MSS CRC without prior A-PD-1, respectively. ORR was 27% in patients with CPS ≥1 and 0% in patients with CPS < 1. ORR was 33% with TMB-high (median as the cut-off) and 12% with TMB-low. Analysis of tumor-infiltrating lymphocytes before treatment and after TAS-116 monotherapy demonstrated reduction of FoxP3hiCD45RA−Tregs fraction in the tumor microenvironment. Conclusions: The combination of TAS-116 160mg plus nivolumab had manageable safety profiles and anti-tumor activity especially for MSS CRC patients, which warrants further investigations in a large cohort. Clinical trial information: UMIN000032801 .
Databáze: OpenAIRE
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