Inclusion Criteria:

- Aged18 years and older.

- Histologically proven malignant solid tumors who were receiving their second, third
or fourth line of palliative chemotherapy and who showed at the second or third
course progressive disease as their maximum response according to the RECIST criteria
or to the IGCG CA125 criteria in case of ovarian cancer patients.

- Measurable disease defined by 1 of the following criteria: Any unidimensional
measurable lesion ≥ 10 mm by standard MRI or CT scan for solid tumors; or at least 1
non-measurable lesion that is evaluable by nuclear medicine, tumor markers, or other
reliable measures.

- Eastern Cooperative Oncology Group (ECOG) performance status ≤2; Absolute leukocyte
count (≥4000/mm3), platelets ≥100,000/mm3, hemoglobin ≥9.0 g/dL; total bilirubin,
aspartate amino transferase (AST) and alanine amino transferase (ALT) <1.5 the upper
normal limit (UNL), creatinine ≤1.2 mg/dL or a calculated creatinine clearance of ≥60
mL/min.

- Life expectancy of more than three months,

- Written informed consent.

Exclusion Criteria:

- History of allergy to hydralazine or valproate.

- Past or present condition of rheumatic disease, central nervous system disease, heart
failure from aortic stenosis and postural hypotension as diagnosed by a physician.

- Previous use of the experimental drugs (hydralazine and magnesium valproate)

- Pregnancy or breast-feeding.

- Uncontrolled systemic disease or infection.