Abstract 3000
Background
High deoxyuridine triphosphatase (dUTPase) in tumor tissue, as a gatekeeper enzyme for 5-fluorouracil (5-FU), is associated with 5-FU resistance. TAS-114 is an oral dUTPase inhibitor which enhance antitumor activity with 5-FU or fluoropyrimidines. Phase I study of TAS-114 in combination with S-1 showed its tolerability and preliminary antitumor signals for patients (pts) with non-small cell lung cancer and advanced gastric cancer (AGC). This phase II study has been conducted to evaluate efficacy and safety of TAS-114 and S-1 combination in pts with AGC.
Methods
The main eligibility criteria is pts with AGC after two or more previous chemotherapy regimens containing fluoropyrimidines, platinum agents, and taxanes or irinotecan. The primary endpoint is objective response rate (ORR) by investigators’ judgement. Using Simon’s optimal two-stage design, 29 pts were required, with one-sided a = 5% and power=80%. The threshold and expected ORRs were 5% and 25%. Protein expression levels of dUTPase and BRCA1 in tumor samples were determined by immunohistochemistry.
Results
The accrual was terminated in June 2018. Of all 20 enrolled pts, the ORR and disease control rate were 5.0% (95% confidence interval [CI], 0.1-24.9%) and 70.0% (95% CI, 45.7-88.1%), respectively. The median progression-free survival (PFS) and overall survival were 2.4 months (95% CI, 1.2-3.3 months) and 7.1 months (95% CI, 5.2-9.4 months), respectively. The median PFS in the groups with high and low dUTPase protein expression in the cytoplasm was 2.8 months (95% CI, 1.4–3.9) and 1.6 months (95% CI, 0.6–2.4), respectively (hazard ratio, 0.40 [95% CI, 0.16–1.04], P = 0.047). Grade 3 or higher treatment-related adverse events were anemia (20%), leucopenia (15%), neutropenia (10%), rash (10%), thrombocytopenia (5%), and Iymphopenia (5%).
Conclusions
TAS-114 with S-1 showed modest antitumor activity with acceptable safety profiles for heavily pretreated pts with AGC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Taiho.
Disclosure
D. Takahari: Research grant / Funding (self): Taiho Pharmaceutical Co; Research grant / Funding (self): Ono Pharmaceutical Co; Honoraria (self): Eli Lilly Japan; Honoraria (self): Bristol-Myers Squibb; Honoraria (self): Yakult Honsha Co; Honoraria (self): Chugai Pharmaceutical Co., Ltd. A. Kawazoe: Honoraria (self), Research grant / Funding (institution): Taiho. K. Shitara: Honoraria (self): Novartis; Honoraria (self): AbbVie; Honoraria (self): Yakult; Advisory / Consultancy: Astellas Pharma; Advisory / Consultancy: Lilly; Advisory / Consultancy: Bristol-Myers Squibb; Advisory / Consultancy: Takeda; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Ono Pharmaceutical; Advisory / Consultancy: MSD; Research grant / Funding (institution): Astellas Pharma; Research grant / Funding (self): Lilly; Research grant / Funding (institution): Ono Pharmaceutical; Research grant / Funding (institution): Dainippon Sumitomo Pharma; Research grant / Funding (institution): Daiichi Sankyo; Research grant / Funding (institution): Taiho Pharmaceutical; Research grant / Funding (institution): Chugai Pharma; Research grant / Funding (institution): MSD; Research grant / Funding (institution): Medi Science. All other authors have declared no conflicts of interest.
Resources from the same session
1619 - Meta-analysis of KRAS Mutation as prognostic factor in patients (pts.) with resection of colorectal (CRC) liver metastases: Tumor burden and Sideness analysis.
Presenter: Maria Romina Luca
Session: Poster Display session 2
Resources:
Abstract
2104 - Clinical implications of regorafenib-induced hypothyroidism in metastatic colorectal cancer refractory to standard therapies: A prospective evaluation
Presenter: Jwa Hoon Kim
Session: Poster Display session 2
Resources:
Abstract
2143 - Clinical impact of BRAF V600E mutations in patients (pts) with resectable solitary colorectal liver metastases (CRLM)
Presenter: Shin Kobayashi
Session: Poster Display session 2
Resources:
Abstract
3136 - Trifluridine/tipiracil in metastatic colorectal cancer: an updated multicentre real-world analysis on efficacy, safety and predictive factors.
Presenter: Chara Stavraka
Session: Poster Display session 2
Resources:
Abstract
4234 - Correlation between p53 expression and clinical outcome in RAS/BRAF wild type metastatic colorectal cancer patients receiving later-line irinotecan-cetuximab
Presenter: Eleonora Lai
Session: Poster Display session 2
Resources:
Abstract
4287 - Safety and effectiveness of aflibercept + FOLFIRI for the treatment of patients with metastatic colorectal cancer (mCRC): OZONE secondary analyses
Presenter: Ian Chau
Session: Poster Display session 2
Resources:
Abstract
1820 - A Phase Ib study of the safety and efficacy of atezolizumab (atezo) + bevacizumab (bev) + cobimetinib (cobi) in patients (pts) with metastatic colorectal cancer (mCRC)
Presenter: Johanna Bendell
Session: Poster Display session 2
Resources:
Abstract
5644 - Development and validation of a metastasis-associated immune prognostic model for concurrent metastatic colorectal cancer
Presenter: Zhiwen Luo
Session: Poster Display session 2
Resources:
Abstract
5697 - Prognostic role of blood cell count-based immuno-inflammatory parameters in the Valentino trial
Presenter: Giovanni Fuca
Session: Poster Display session 2
Resources:
Abstract
4704 - Evaluation of safety, immunogenicity and preliminary efficacy of PolyPEPI1018 vaccine in subjects with metastatic colorectal cancer (mCRC) with a predictive biomarker
Presenter: Joleen Hubbard
Session: Poster Display session 2
Resources:
Abstract