Ruxolitinib in Patients With Breast Cancer

Objectives: Primary * The primary objective of this two-stage, phase II study is to estimate the objective response rate to ruxolitinib in patients with metastatic or unresectable locally advanced breast cancer which is pStat3+ and which has progressed on at least one line of chemotherapy for advanced disease, and/or has recurred within 12 months of completion of neoadjuvant/adjuvant chemotherapy. Secondary * To describe the toxicity profile * To evaluate clinical benefit rate (CR + PR + SD \>/= 24 weeks) * To estimate progression-free and overall survival Exploratory * To explore whether baseline hs-CRP level higher than the group median is associated with objective response * To explore whether baseline IL-6 level higher than the group median is associated with objective response * To describe hs-CRP level over time, and to describe the proportion of patients with a) hs-CRP \> 3mg/L at baseline, on treatment, and at time of progression, and b) hs-CRP \> 1mg/L at baseline, on treatment, and at time of progression * To describe IL-6 level over time, and to describe the proportion of patients with IL-6 level above the upper limit of normal at baseline, on treatment, and at time of progression * To describe pStat3 status by IHC in baseline metastatic biopsies * To describe pStat3 status by IHC in on-study biopsies * To describe pStat3 status by IHC in the time of progression biopsy samples * To characterize archival and metastatic biopsy samples using triple immunofluorescence for CD44, CD24, and pStat3 * To characterize archival and metastatic biopsy samples using a previously characterized pStat3 gene signature * To characterize circulating tumor cells (CTCs) for CD44, CD24, and pStat3 at baseline and time of progression