Neoadjuvant Phase II Trial in Patients With T1c Operable, HER2-positive Breast Cancer According to TOP2A Status

In this phase II study, we propose a treatment strategy that not only takes advantage of the complementary action of trastuzumab and pertuzumab but also the relevance of an anthracycline-based regimen. Indeed, besides the cardiac toxicity that can be induced by these three agents, anthracycline chemotherapy may not confer benefit to all patients.

The underlying scientific hypothesis is based on data from the NEOSPHERE neoadjuvant trial showing that addition of pertuzumab to trastuzumab plus docetaxel improved the pCR rate (46% versus 29% without pertuzumab) in T2-T3 tumors. Therefore, we hypothesize that for smaller tumors (T1c), the pCR rate should be higher, on the order of 60% in patients with the coamplification (with anthracycline therapy) and 55% for the group without coamplification (without anthracycline therapy). The sample size of 90 patients (45 per group) planned for the phase II study will allow 15% precision with the expected pCR rates of 60% (95%CI: 45%-75%) for patients with coamplification and 55% (95%CI: 40%-70%) for those without coamplification. In addition, exploratory analyses will aim to identify predictive markers of pCR in order to target biologically defined subpopulations in which pCR rates might even be higher.

Inclusion criteria

• Women aged ≥ 18;
• Patient has histologically confirmed breast cancer, with a clinical tumour diameter of > 1 cm (cT1c, cT2-3 or T4a)-
• Any N status
• No clinically or radiologically detectable metastases (M0);
• HR negative (both ER and PR < 10% by IHC); for T1c status, otherwise HR negative or positive
• Her-2 positive (i.e. IHC score 3+ or FISH/SISH/CISH positive);
• Performance status ≤ 1 (according to WHO criteria);
• Patients not previously treated by surgery, radiotherapy, hormone therapy or chemotherapy;
• Hæmatology: Absolute neutrophil count (ANC) ≥1,500/mm³; Platelets ≥100,000/mm³; Total white blood cell count (WBC) ≥3.000/mm³; Hb> 9g/dl;
• Hepatic Function: Total bilirubin ≤1.5 time the upper normal limit (UNL); ASAT ≤ 1.5xUNL; ALAT ≤ 1.5xUNL; Alkaline phosphatase ≤ 2.5xUNL;
• Renal Function: Serum creatinine ≤1.5xUNL (and if Serum creatinine >1.5xUNL, Creatinine clearance ≥50 mL/min (MDRD formula);
• Metabolic Function: Magnesium ≥ lower limit of normal; Calcium ≥ lower limit of normal;
• Patient with not controlled heart disease and for whom anthracyclines are not contraindicated. Cardiac ejection fraction ≥50% measured by MUGA or ECHO done within 4 weeks before inclusion;
• Patient agreeing to use effective contraception during and for ≥ 7 months after completion of study treatment;
• Patient able to comply with the protocol;
• Patient must have signed a written informed consent form prior to any study specific procedures;
• Patient must be affiliated to a Social Health Insurance.

Exclusion criteria

• Bilateral or multifocal breast cancer;
• Non-measurable tumour;
• Any form of breast cancer other than those described in the inclusion criteria, particularly inflammatory and/or overlooked forms (T4b or T4d);
• HER2 negative status (i.e. IHC score 0 or 1+, or IHC score 2+ and FISH/SISH/CISH negative);
• RH positive (ER or PR ≥ 10% by IHC) ;
• Patient has a history of second cancer, with exception of in situ cervical cancer or basocellular skin cancer which is regarded as cured;
• Patient has already been treated for new breast cancer;
• Patients have already undergone surgery for their disease or have had primary axillary dissection;
• Prior docetaxel administration or anti-HER2 antibody therapy (e.g.: trastuzumab or pertuzumab);
• Patients with other concurrent severe and/or uncontrolled medical disease which could compromise participation in the study, such as, but not limited to:

• Heart or kidney failure, medullary, respiratory or liver failure, dyspnea
• Clinically significant cardiovascular disease (including myocardial infarction, unstable angina, symptomatic congestive heart failure, serious uncontrolled cardiac arrhythmia, poorly controlled hypertension) ≤ 1 year before enrollment
• Uncontrolled diabetes
• Significant neurological or psychiatric abnormalities
• Symptomatic or progressive disorder of the central nervous system (CNS) or metastasis at the initial check-up.
• Peripheral neuropathy > grade 2
• Acute urinary infection, ongoing hemorrhagic cystitis;
• Patients with a known history of HIV seropositivity;
• Sensitivity to any of the study medications or any of the ingredients or excipients of these medications;
• Patients receiving of the concomitant medications with phenytoin;
• Patients who received any other investigational drugs within 30 days of initiation of treatment and/or during the study;
• Must not have had a major surgical procedure within 30 days of initiation of treatment;
• Pregnant women, women who are likely to become pregnant or are breast-feeding;
• Patients with any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule; those conditions should be discussed with the patient before registration in the trial;
• Patients with history of non compliance to medical regimens or unwilling or unable to comply with the protocol;
• Individual deprived of liberty or placed under the authority of a tutor.