Inclusion Criteria:

- Histological or cytological diagnosis of small-cell lung cancer (SCLC)

- SCLC refractory to prior chemotherapy regimen including platinum derivatives
(cisplatin or carboplatin) and etoposide, either primary refractory (immediate
progression or recurrence less than 3 months after the end of previous chemotherapy)
or secondary refractory (sensitive patients to platinum plus etoposide in first-line,
progressing or recurring less than 3 months after reintroduction of the same
chemotherapy).

- At least one evaluable or measurable lesion

- Availability for participating in the detailed follow-up of the protocol

- Signed informed consent.

Exclusion Criteria:

- Patient who were previously treated with anthracyclin or vinca-alcaloid derivatives
or cyclophosphamide

- Performance status < 60 on the Karnofsky scale

- A history of prior malignant tumour, except non-melanoma skin cancer or in situ
carcinoma of the cervix or of the bladder or cured malignant tumour (more than 5-year
disease free interval)

- A history of prior HIV infection

- Polynuclear cells < 2,000/mm³

- Platelet cells < 100,000/mm³

- Abnormal coagulation tests (aPTT, PTT, prothrombin time) and/or decreased fibrinogen

- Serum bilirubin >1.5 mg/100 ml

- Transaminases more than twice the normal range

- Serum creatinine > 1.5 mg/100 ml

- Recent myocardial infarction (less than 3 months prior to date of diagnosis)

- Congestive cardiac failure (ejection fraction of the left ventricle < 50%) or
uncontrolled cardiac arrhythmia

- Uncontrolled infectious disease

- Active epilepsy needing a specific treatment

- Concomitant treatment with IMAO, carbamazepine, mefloquine, phenobarbital, primidone,
phenytoïn, lamotrigine, zidovudine

- Pregnancy or refusal to use active contraception

- A known allergy to valproic acid and/or doxorubicin, cyclophosphamide, vindesine

- Serious medical or psychological factors which may prevent adherence to the treatment
schedule.