Inclusion Criteria:

- Histologically or cytologically proven diagnosis of SCLC;

- Limited or extensive-stage disease in patients who have received a single
chemotherapy regimen or combined modality (chemotherapy + chest radiotherapy) regimen
and relapsed after completion of first-line chemotherapy (sensitive relapse);

- Age >/= 18 years;

- ECOG Performance Status 0-2;

- Life expectancy of at least 12 weeks;

- Measurable lesions according to RECIST criteria;

- Adequate cardiac, hepatic, renal, and bone marrow function;

- Written informed consent.

Exclusion Criteria:

- Prior treatment with an HDAC inhibitor;

- Symptomatic and/or unstable pre-existing brain metastases;

- Superior Vena Cava Syndrome;

- Spinal cord compression;

- Severe or uncontrolled medical diseases (Hypertension, diabetes, congestive heart
failure, myocardial infarction within 6 months of study, chronic renal disease, or
active uncontrolled infections);

- Other co-existing malignancies or malignancies diagnosed within the last 5 years with
the exception of basal cell carcinoma or cervical cancer in situ;

- Pregnant or breastfeeding women.