TPS1106 Background: Paclitaxel is a microtubule-stabilizing drug used for various cancers including breast cancer (BC) and gastric cancer (GC). DHP107 is an oral paclitaxel solution formulated with non-toxic excipients using DH-LASED technology, which doesn’t require pre-treatment. DHP107 demonstrated comparable efficacy and safety to IV paclitaxel for patients with advanced GC (Ann Oncol 2018), and was market approved as the first oral paclitaxel in 2016 for GC in Korea. In previous OPTIMAL phase II study, the primary endpoint objective response rate (ORR) was 54.5% in HER2 negative metastatic BC (MBC) patients and 44.4% in triple negative BC (TNBC) patients. Disease control rate (DCR) was 90.9% by the investigators’ assessment. Toxicity was manageable (2019 ESMO). OPTIMAL phase III is being conducted in Korea, China and Eastern Europe based on this result and another phase II study (OPERA) is being performed in USA. Methods: OPTIMAL 3 study is a multinational, multi-center, randomized and open-label trial enrolling HER2 negative (HR+/HER2- or TNBC) recurrent or metastatic BC patients. Patients are randomized to either study (DHP107) or control group (IV paclitaxel) in a 1:1 ratio and stratified by disease free interval (DFI≤48 weeks vs >48 weeks), visceral metastasis status (visceral vs non-visceral) and country. Patients are administrated with DHP107 (200mg/m2 p.o. bid) or IV paclitaxel (80mg/m2 infused) on D1, 8, 15, q4wks. Tumor assessments are performed on every 8 weeks (±7 days) from C1D1 until disease progression (RECIST V1.1). Key inclusion & exclusion criteria are hormone receptor (ER/PR) positive or negative, HER2 negative, ECOG performance status ≤1 and no prior chemotherapy in recurrent or metastatic disease. The primary endpoint is progression free survival (PFS). Secondary endpoints include ORR, overall survival (OS), time to treatment failure (TTF), DCR, quality of life (QoL) and safety. Total target number of patients is 476 with an estimated 10% drop-out rate. The test is based on non-inferiority hypothesis (HR=1.33) with 80% power. The primary endpoint will be analyzed using a one-sided test at a 2.5% significance level, and other endpoints will be analyzed using a two-sided test at a 5% significance level, with 95% confidence interval. The first subject was enrolled in Jan 2019 and recruitment is ongoing and is expected to be completed in Dec 2020. Final results of this study will be announced by the end of 2022. Clinical trial information: NCT03315364 .
A multicentre phase II study of the efficacy and safety of docetaxel as first-line treatment of advanced breast cancer: Report of the Clinical Screening Group of the EORTC