Targeting Triple Negative BREAst Cancer Metabolism With a Combination of Chemoimmunotherapy and a FASTing-like Approach in the Preoperative Setting: the BREAKFAST 2 Trial

TNBC is the most aggressive subtype of breast cancer. TNBC patients who achieve pCR during neoadjuvant chemo-immunotherapy have significantly lower rates of disease recurrence or death. Preclinical studies indicate that combining nutrient starvation, in the form of cycles of FLA, with anthracycline- or platinum-based chemotherapy remarkably increases the therapeutic index of chemotherapy against murine and human models of breast cancer, including models of TNBC. In particular, the chemotherapy-fasting/FLA combination increases the anticancer activity of chemotherapy, while reducing treatment-related adverse events (AEs). Moreover, the FLA has demonstrated potent and desirable immunomodulatory effects both in in vivo studies and in patients with cancer, and the activation of antitumor immunity is a crucial mediator of the anticancer effects of the FLA, either alone or in combination with chemotherapy. Therefore, there is a strong biological rationale to combine cyclic FLA with ICIs in cancer therapy. Based on these data, we hypothesize that combining the FLA with standard-of-care, preoperative, anthracycline-taxane-carboplatin chemotherapy plus Pembrolizumab can increase the rate of pCR in a population of patients with stage II-III TNBC. This is an Italian, multicenter, open-label, two-arm, comparative, randomized phase II study. This study is designed to investigate if the addition if the experimental metabolic intervention consisting in cycles of FLA, as administered every three weeks up to a maximum of 8 consecutive cycles, is able to increase the anticancer activity of standard preoperative chemo-immunotherapy consisting of antracycline-taxane-carboplatin-based chemotherapy plus pembrolizumab in patients with treatment naïve, localized (tumor stage T1c AND nodal stage N1-2, or tumor stage T2-4 AND nodal stage N0-2) invasive Triple Negative Breast Cancer (HER2 negative, ER \<1%, PgR \<1%). Bilateral and/or multifocal primary tumor is allowed, as well as inflammatory breast cancer, and the tumor with the most advanced T stage should be used to assess the eligibility. If multi-focal/multi-centric disease, TNBC needs to be confirmed for each focus. The primary study endpoint is pathologic complete response (pCR). Patients will be randomly allocated to one of the following treatment arms: * Arm A (control arm): 12 consecutive cycles of weekly paclitaxel plus carboplatin (PCb) combined with 4 triweekly cycles of Pembrolizumab, followed by 4 consecutive cycles of triweekly anthracycline (doxorubicin or epirubicin)-cyclophosphamide (AC or EC) chemotherapy combined with 4 triweekly cycles of Pembrolizumab. This combination treatment will be further referred to as "standard treatment". * Arm B (experimental arm): standard treatment in combination with up to a maximum of 8 consecutive triweekly cycles of 5-day FLA. Enrolled patients will be randomized in a 1:1 ratio and stratified according to a) disease stage: stage II (T1N1, T2N0, T2N1, T3N0) vs. stage III (T3N1; any T4; any N2); b) patient body mass index (BMI ≥25 kg/m2 vs \<25 kg/m2). After completion of the experimental preoperative protocol, patients will undergo surgery between 14 and 28 days after the last chemotherapy administration. After surgery, patients will receive 9 additional triweekly pembrolizumab administration at the same dosage, and regardless of the pathologic tumor response (pCR yes vs. no). After surgery, patients may receive local radiotherapy, depending on the pathological stage and according to local and international guidelines.