A Study of Ruxolitinib in Combination With Capecitabine in Subjects With Advanced or Metastatic HER2-negative Breast Cancer

Inclusion Criteria:

- Histologically or cytologically confirmed HER2-negative adenocarcinoma of the breast

- Locally advanced (Stage 3B) or metastatic (Stage 4) disease

- Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2

- Received up to 2 prior chemotherapy regimens (not including neoadjuvant/adjuvant
therapy) for advanced or metastatic disease

- Participants with hormone-receptor positive tumors must have failed available lines of
hormonal therapy unless hormone therapy was not tolerated or not clinically
appropriate

- ≥ 2 weeks elapsed from the completion of previous treatment regimen and must have
recovered or be at a new stable baseline from any related toxicities

- Radiographically measurable or evaluable disease

- An mGPS of 1 or 2 as defined below:

- Criteria:

1. modified Glasgow prognostic score (mGPS) of 1: CRP > 10 mg/L and albumin ≥
35 g/L

2. mGPS of 2: C-reactive protein (CRP) > 10 mg/L and albumin < 35 g/L

Exclusion Criteria:

- Received prior treatment with capecitabine or fluoropyrimidine for advanced or
metastatic disease

- Received more than 2 prior regimens for advanced or metastatic disease (not including
hormonal therapy in the metastatic setting or neoadjuvant or adjuvant therapies)

- Unknown hormone-receptor status

- Ongoing radiation therapy or radiation therapy administered within 2 weeks of
enrollment

- Concurrent anticancer therapy

- Inadequate renal, hepatic or bone marrow function

- Another current or previous malignancy within 2 years of study entry unless approved
by the sponsor