This study is set up to determine whether soluble beta-glucan (SBG) has

• unfavourable side effects
• beneficial treatment effects when given in combination with standard antibody and chemotherapy to patients with breast cancer.

Inclusion Criteria:

1. Women with histologically/cytologically confirmed locally advanced or metastatic breast cancer
2. Primary tumor or metastases are HER2-ICH3+ or FISH+
3. Measurable or non-measurable disease
4. The patients must not have received treatment with the combination trastuzumab and vinorelbine previously
5. Expected lifetime of more than 12 weeks
6. Age ≥ 18 years
7. Performance status ≤ 2 according to World Health Organization (WHO) scale
8. The patient must be able to comply with the protocol
9. Verbal and written informed consent

Exclusion Criteria:

1. Women who are pregnant or breast-feeding. A negative pregnancy test must be provided during the screening period for fertile women. Fertile women must use effective contraceptive methods
2. Clinical symptoms indicating central nervous system involvement
3. Other current or former malignant disease, with the exception of adequately treated and cured carcinoma in situ cervicis uteri and basocellular skin carcinomas
4. Left ventricular ejection fraction (LVEF) < 50% of normal range
5. Reduced bone marrow function defined by leukocyte counts < 3.0 x 109/l and neutrophil counts < 1.5 x 109/l, or thrombocyte counts ≤ 100 x 109/l
6. Reduced liver function defined by bilirubin > 3 x upper normal limit and/or ASAT/ALAT > 3 x upper normal limit and/or alkaline phosphatase > 3 x upper normal limit.
7. Reduced renal function defined by serum creatinine > 2 x upper normal limit