Pre Operative Trastuzumab in Operable Breast Cancer

Background Information and Rationale:

Trastuzumab is a humanized monoclonal antibody that acts extracellularly on the erbB-2 receptor.Trastuzumab is a recombinant humanized IgG1 monoclonal antibody against the human epidermal growth factor receptor 2 (HER2/erbB-2),which has shown in both in vitro assays and in animals, to inhibit the proliferation of human tumour cells that overexpress erbB-2. Additionally, trastuzumab is a potent mediator of antibody-dependent cell-mediated cytotoxicity (ADCC). In vitro, trastuzumab-mediated ADCC has been shown to be preferentially exerted on erbB-2 overexpressing cancer cells compared with cancer cells that do not overexpress erbB-2. Trastuzumab has emerged as a widely accepted standard of care for erbB-2-positive disease. (Metastatic/ adjuvant/neoadjuvant.

Our current hypothesis suggests that the cells which are disseminated at the time of surgery will encounter an inhospitable environment which will be anti-HER in nature. Therefore combining the above mentioned streams of thought, we would like to assess the effect of a short pre-operative course of Trastuzumab on breast cancer relapse. The study is proposed in HER2 positive patients with operable breast cancer.

Objectives :

Primary

The primary objective of the study is to see the effect of short duration of peri-operative Trastuzumab on disease-free survival in comparison in all patients

Secondary

The safety of the pre-operative therapies including the early post operative morbidity

1. Overall survival (OS) in all patients and in pathologically node positive patients.
2. The level of circulating tumor cells (CTCs) in the peripheral blood assessed before starting pre-operative therapy and at the same time point in the control arm, level of CTCs 10 minutes prior to start of surgery, during surgery and 10 days after surgery on 40 consecutive consenting patients (20 in each arm). The levels of circulating chromatin will also be estimated at the same time points as CTC for these 40 patients.
3. Evaluation of the paraffin blocks for pTEN loss6-8 and p95ErbB2 truncated form of HER2 on 100 consecutive consenting patients (50 in each arm).9-11

Study Design :

This is phase 3, randomized Double blinded parallel group study of Trastuzumab in pre operative setting in operable breast cancer patients.

Approximately 1000 patients with Women with HER2neu positive, T1/T2/T3 and N0/N1. clinical T4 and/or N2 disease who are considered operable by the treating surgeon with histopathological diagnosis on core biopsies, will be included in the study. Patients with T4 or N2 (locally advanced and large operable for neo-adjuvant chemotherapy) will not be included. All node positive patients will receive single injection of Depot Inj. Progesterone 500 mg deep IM 4 -14 days prior to surgery

Patients will be stratified, before randomization for Tumor size, menopausal status, and affordability for Trastuzumab and centre of the study. These patients will then be randomized 1:1 to receive the following

Intervention arm: .A single dose of Trastuzumab (Herceptin, Hoffman La Roche) at 8 mg/Kg as a 90 minute intravenous infusion in 250 ml of normal saline, in the window period of 10-15 4 to 14 days (both days inclusive) prior to the planned date of surgery.

Control arm: A 90 minute intravenous infusion of saline as placebo

All patients will thereafter receive standard post-operative adjuvant therapy as per local institutional practice including hormonal therapy, chemotherapy and radiation therapy.