Transfusional dependence has been associated closely and independently with low survival in patients with myelodysplastic syndrome (MDS), especially in patients at low risk according to IPSS. Treatment of patients with hydralazine + valproic acid as an alternative to treatment with 5-azacytidine has lower cost and possibly as effective with fewer side effects. The objective of this phase II study is to determine the effectiveness of combination therapy with hydralazine + Ac. Valproic compared with best supportive care. The investigators will select 42 patients per group, and after 14 weeks of treatment the investigators will study in both groups the hematological response (transfusion-dependent, hemoglobin, cytogenetics and morphology) and treatment safety (adverse reactions and vital signs) to 1 year after starting treatment. The concentration of hemoglobin, the number of transfusions, platelets, neutrophils and other continuous variables in both groups will be compared by Student t or Mann-Whitney, as appropriate. For comparison of cytogenetic and morphological response and other categorical variables between groups Chi square will be used. And within each group the investigators will compare each of these variables before and after treatment by t-test for paired data or Wilcoxon test.

Inclusion Criteria:

1. Ability to understand and voluntarily sign the consent form.
2. Age ≥ 18 years at the time of signing the informed consent form.
3. Ability and willingness to meet the schedule of study visits and other protocol requirements.
4. Documented diagnosis of SMDs according to the criteria of disease risk IPSS intermediate-2, high risk or any risk with transfusion requirements.
5. Transfusion-dependent anemia erythrocytes defined as the absence of a period of 56 consecutive days without transfusion of red blood cells for at least 112 days prior (16 weeks).
6. Engage both women and men to use highly effective contraception.
7. Patients are not candidates for treatment with azacitidine or chemotherapy

Exclusion Criteria:

• Patients who have any of these exclusion criteria may not be included in the trial:

  1. Pregnant or breastfeeding.
  2. After hematopoietic stem cell transplantation.
  3. Patients with vitamin B12 deficiency, Folic Acid and Iron
  4. Any severe psychiatric illness or condition that prevents the patient sign the consent form for the patient or involves an unacceptable risk in case of participating in the study.
  5. Hypersensitivity to hydralazine and / or AC. Valproic