Inclusion Criteria:

- adult patients, >=18 years of age;

- diagnosis of MDS, according to IPSS criteria;

- low or intermediate risk, who are not candidates for treatment with growth factors,
or who have not responded to these treatments.

Exclusion Criteria:

- previous treatment with CellCept, or any erythropoietin-stimulating drug;

- diagnosis of proliferative chronic myelomonocytic leukemia;

- prior or concomitant malignancies other than MDS, with the exception of basocellular,
spinocellular or adequately treated in situ cervical cancer,in the past 3 years;

- biological antitumor and myelosuppressive treatment within 28 days before start of
study;

- bone marrow precursor cell transplantation previous to study.