J. Pierga (Paris, CE, France)

Institut Curie

Author Of 1 Presentation

 On-Demand ePoster Display

113P - Efficacy of oral etoposide associated with trastuzumab in HER2-positive metastatic breast cancer: results from the Institut Curie’s database.

Abstract

Background

The TOP2A (encoding topoisomerase II) and HER2 genes are co-amplified in about 40% of HER2 positive (HER2+) breast cancers. The topoisomerase-II inhibitor etoposide (oral VP16) has demonstrated clinical activity in metastatic breast cancer (MBC). However, the clinical benefit of trastuzumab combined with oral VP16 (T-VP16) in HER2+ MBC has not been evaluated.

Methods

Patients treated at Institut Curie Hospitals (Paris and Saint Cloud, France) with T-VP16 for HER2+ MBC were retrieved by an in-silico search. A waiver of informed consent was obtained from the local IRB. Clinical and pathological data were collected by trained medical oncologists. The primary study endpoint was progression-free survival (PFS) assessed by the Kaplan Meier method. Secondary endpoints were: overall survival (OS), long response rate (PFS>6 months), clinical benefit (defined as a PFS than 6 months AND longer than the PFS achieved by the previous line of treatment), response rate, and toxicity.

Results

From 2008 to 2016, 43 patients with HER2+ MBC who received T-VP16 were included. The median number of previous chemotherapy lines was 7 (range 1-13). The median PFS and OS were 2.9 months (95% CI [2.4-4.7]) and 11.3 months (95% CI [8.3-25.0]), respectively. Twelve patients (27.9%) had a long response to treatment including nine (20.9%) with clinical benefit. A complete response was obtained for 3 patients. Only 4 patients stopped treatment for toxicity.

Conclusions

The favorable clinical benefit, good tolerance and low cost suggest that T-VP16 is a relevant option for patients with heavily pretreated HER2-positive MBC. TOP2A and HER2 co-amplification data will be presented at the meeting.

Legal entity responsible for the study

Institut Curie.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.

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