An overview of the Japan Breast Cancer Research Group (JBCRG) activities

Safety and pharmacokinetics of ramucirumab in combination with docetaxel in Japanese patients with locally advanced or metastatic breast cancer: a Phase Ib study

OBJECTIVE

The primary objective of this study was to investigate the safety and tolerability and to confirm the recommended dose of the anti-vascular endothelial growth factor receptor 2 monoclonal antibody ramucirumab in combination with docetaxel in Japanese patients with metastatic/locally advanced breast cancer.

METHODS

In this multicenter, single-arm, Phase Ib trial, eligibility criteria included: 20 years or older, Eastern Cooperative Oncology Group performance status of 0/1 and confirmed diagnosis of human epidermal growth factor receptor 2-negative metastatic/locally recurrent inoperable breast adenocarcinoma. Patients received docetaxel (75 mg/m2) followed by ramucirumab (10 mg/kg) on Day 1 of 21-day cycles. Recommended dose was defined as <33% dose-limiting toxicities in dose-limiting toxicity-evaluable patients in Cycle 1. The safety, pharmacokinetics, immunogenicity and antitumor activity were examined.

RESULTS

Seven patients were treated. Most adverse events were mild to moderate. Two patients during Cycle 1 experienced a dose-limiting toxicity; one patient each experienced Grade 3 febrile neutropenia and Grade 3 gingivitis. Both dose-limiting toxicities subsequently resolved. No patients discontinued study therapies during Cycle 1. Four serious adverse events were possibly related to ramucirumab in combination with docetaxel. Anti-ramucirumab antibodies were not detected. Pharmacokinetic analysis revealed low total body clearance and long apparent terminal elimination half-life (~7-12 days). Partial response was reported in four patients.

CONCLUSIONS

The combination of ramucirumab and docetaxel was tolerable in female Japanese patients with breast cancer. Ramucirumab 10 mg/kg in combination with docetaxel (75 mg/m2) was confirmed as the recommended dose among Japanese patients, supporting its use in future studies.

Prognostic significance of subtype and pathologic response in operable breast cancer; a pooled analysis of prospective neoadjuvant studies of JBCRG

PURPOSE

In the past decade, JBCRG has conducted three studies of neoadjuvant chemotherapy which have examined sequential combination of fluorouracil, epirubicin and cyclophosphamide, and docetaxel. The present study is a pooled analysis of these studies performed to determine the prognostic significance of pathologic complete response (pCR) and predictive variables for pCR.

METHODS

A total of 353 patients were included. pCR was defined as the absence of invasive cancer or only a few remaining isolated cancer cells in the breast (quasi-pCR, QpCR).

RESULTS

Disease-free survival (DFS) and overall survival (OS) were not significantly different among studies, and patients who achieved a QpCR had significantly better prognosis (DFS, p < 0.001; OS, p = 0.002). Patients with triple-negative (TN) tumors had worse prognosis than patients with the other subtypes (DFS, p = 0.03; OS, p = 0.10). A Cox proportional hazards model showed node-positive, TN, and QpCR were the significant predictors for DFS and OS among study, age, tumor size, nuclear grade, nodal status, subtype, clinical response, and pathologic response (DFS; node-positive, HR = 2.29, p = 0.001; TN, HR = 3.39, p < 0.001; QpCR, HR = 0.27, p < 0.001: OS; node-positive, HR = 3.05, p = 0.003; TN, HR = 4.92, p < 0.001; QpCR, HR = 0.12, p < 0.001). In a logistic regression analysis, subtype and clinical response before surgery were the significant predictive variables for QpCR (luminal/Her2-positive, odds ratio (OR) = 4.15, p = 0.002; Her2-positive, OR = 6.24, p < 0.001; TN, OR = 4.24, p < 0.001; clinical response before surgery, OR = 2.41, p = 0.019).

CONCLUSIONS

This study confirmed the prognostic significance of QpCR and nodal status and the predictive and prognostic significance of subtype in neoadjuvant chemotherapy.