Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed non-small cell lung cancer, meeting 1 of
the following criteria:

- Stage IV disease

- Stage IIIB disease with malignant pleural effusion

- Recurrent disease

- Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by
conventional techniques OR ≥ 10 mm by spiral CT scan

- Previously treated with 1, and only 1, cytotoxic chemotherapy regimen for Stage IIIB
or IV or recurrent disease

- Brain metastases allowed provided they are clinically and radiologically stable for 4
weeks after treatment with surgery and/or radiotherapy AND there is no requirement
for steroids

PATIENT CHARACTERISTICS:

Age

- Over 18

Performance status

- ECOG 0-1 OR

- Karnofsky 70-100%

Life expectancy

- More than 3 months

Hematopoietic

- WBC ≥ 3,000/mm^3

- Absolute neutrophil count ≥ 1,500/mm^3

- Platelet count ≥ 100,000/mm^3

Hepatic

- Bilirubin normal

- AST and ALT ≤ 2.5 times upper limit of normal

Renal

- Creatinine normal OR

- Creatinine clearance ≥ 60 mL/min

Cardiovascular

- No symptomatic congestive heart failure

- No unstable angina pectoris

- No cardiac arrhythmia

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception before, during, and for 3 months
after completion of study treatment

- No peripheral neuropathy > grade 1

- No other active malignancy within the past 5 years except nonmelanoma skin cancer

- No ongoing or active infection

- No psychiatric illness or social situation that would preclude study compliance

- No history of allergic reaction attributed to compounds of similar chemical or
biological composition of study drug

- No other uncontrolled illness

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Not specified

Chemotherapy

- See Disease Characteristics

- At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)

Endocrine therapy

- Not specified

Radiotherapy

- See Disease Characteristics

- At least 3 weeks since prior radiotherapy

- No prior radiotherapy to the only site of measurable disease unless there is
subsequent disease progression

Surgery

- See Disease Characteristics

Other

- At least 2 weeks since prior valproic acid

- No other concurrent investigational agents

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No other concurrent anticancer therapy