Inclusion Criteria:

- World Health Organization (WHO) Performance Status of ≤ 2

- Patients with HER2+ breast cancer by local laboratory testing (immunohistochemistry
[IHC] 3+ staining or fluorescence in situ hybridization [FISH] confirmation for IHC
2+ and 1+)

- Documented tumor resistance to trastuzumab:

- Recurrence while on trastuzumab or within 12 months since the last infusion for
patients who received trastuzumab as adjuvant treatment

- Progression while on or within 4 weeks since the last infusion of trastuzumab
for patients who received trastuzumab for metastatic disease.

- Documented evidence of progressive disease per Response Evaluation Criteria in Solid
Tumors (RECIST) on trastuzumab-based therapy defined as:

- Phase Ib: at any time before study entry

- Phase II: within 16 weeks before date of first dosing

- Received at least 1 but no more than 4 prior anit-HER2 based regimens including at
least 1 regimen containing trastuzumab (adjuvant or neo-adjuvant trastuzumab will be
considered as one prior regimen). HER2 directed therapies are defined as comprising
trastuzumab, lapatinib, and trastuzumab-DM1 (T-DM1) only.

• Phase II only: trastuzumab, T-DM1 or lapatinib must be part of the most recent line
of therapy

- Previous lines of cytotoxic chemotherapy:

- Phase Ib: no more than 4 lines of cytotoxic chemotherapy

- Phase II: no more than 3 lines of cytotoxic chemotherapy

Measurable disease:

- Phase Ib: patient has at least one measurable lesion or non-measurable disease as
defined per RECIST

- Phase II: patient has at least one measureable lesion as defined per RECIST

// Specific Inclusion Criteria for patients in BM cohorts:

- Patient has evidence of progressing brain metastases and/or new metastatic brain
lesion(s) without leptomeningeal disease.

- Patient has received prior WBRT and/or SRS at at >28 and >/= 14 days, respectively,
prior to starting study drug and the patient must have recovered from the side
effects of the therapy

- WHO performance status of
- PT INR
- Any number of prior HER2-directed and cytotoxic regimens, and the most recent line
may be any type of anti-neoplastic therapy

// Exclusion Criteria:

- Patients with untreated brain metastases

- Patients with acute or chronic liver, renal disease or pancreatitis

- Patients with any peripheral neuropathy ≥ Common Terminology Criteria for Adverse
Events (CTCAE) grade 2

- Patients with a history of mood disorders or ≥ CTCAE grade 3 anxiety

- Patient with clinical manifest diabetes mellitus or steroid-induced diabetes mellitus

// Specific Exclusion Criteria for patients in BM cohorts

- Prior treatment with capecitabine

- Patient has known dihydropyrimidine dehydrogenase (DPD) deficiency

- Patient is currently receiving treatment with EIAED

- Other protocol-defined inclusion/exclusion criteria may apply