Results Loss of MLH1 was observed in 18/47 (38.3%) patients. Age of patients did not differ between MLH1-negative and MLH1-positive tumors (61.2±11.0 years and 61.4 ±10.4 years, respectively). The comparison of characteristics of the tumors with and without MLH1 loss is summarized in table 1.Conclusions Loss of MLH1 was associated with bigger tumors, MELF pattern of myoinvasion, and positive lymph nodes. Tumors with MLH1 loss presented more myometrial infiltration, more LVSI, and more TILs, although it did not reach a statistical level of significance. The presence of higher percentage of TILs, as well MLH1 loss itself, may indicate immunotherapy susceptibility.

Background: TNBC often exhibits activation of PI3K/Akt signaling, associated with loss of PTEN expression, low INPP4B expression, and/or increased AKT3 amplification. Inhibition of the PI3K/Akt pathway in diverse cancers leads to radiosensitization and/or chemosensitization. Ipat is an oral, potent ATP-competitive small molecule inhibitor of all three isoforms of Akt. The combination of ipat with taxanes in preclinical models resulted in enhanced efficacy relative to either ipat or chemotherapy alone. In a Phase Ib clinical study, the combination of ipat with diverse chemotherapy regimens was well-tolerated and resulted in RECIST responses, particularly pts with tumors having PI3K/Akt activation. Methods: FAIRLANE is a randomized, double-blind, placebo controlled, multicenter, neoadjuvant Phase II study designed to estimate the efficacy of ipat combined with pac versus placebo combined with pac in women with Stage Ia  IIIa TNBC. Approximately 150 pts (Pts) will be enrolled, randomized in a 1:1 ratio, and stratified by PTEN status, node involvement, and tumor size. Pts will receive 3 cycles of ipat 400 mg or placebo orally once daily on Days 1 to 21 of each 28-day cycle, along with pac 80 mg/m2 every 7 days for a total of 12 doses. All pts will undergo pretreatment and Day 8 tumor tissue acquisition to evaluate pathway biomarkers. Following three cycles of treatment, pts will undergo surgery. The primary efficacy endpoint, pCR within the breast and axilla (ypT0/Tis ypN0) in all pts and in pts with PTEN low tumors, will be assessed by local pathology evaluation following completion of neoadjuvant therapy and surgery. Additional endpoints include objective response rate, safety, BCS rate, pharmacokinetics, and pathway biomarkers. Following surgical resection of primary tumor, pts are expected to continue post-operative treatment with a standard adjuvant chemotherapy regimen at physician's discretion. The study is open for accrual. Clinical trial information: NCT02301988. Citation Format: Saura C, Isakoff SJ, Calvo I, Patt D, Andersen J, Gonzalez-Martin A, Fisher J, Ciruelos E, Gil-Gil M, De la Peña L, Choi Y, Jia S, Singel S, Patel PH, Baselga J, Oliveira M. FAIRLANE: A phase II randomized, double-blind, study of the Akt inhibitor ipatasertib (Ipat, GDC-0068) in combination with paclitaxel (Pac) as neoadjuvant treatment for early stage triple-negative breast cancer (TNBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT1-03-09.