Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed non-small cell lung cancer (NSCLC)
Locally advanced or metastatic disease Received a prior first-line taxane (as a single
agent or component of a combination regimen) as the only chemotherapy for locally advanced
or metastatic disease Any amount of prior adjuvant chemotherapy allowed Bidimensionally
measurable disease outside the field of prior radiotherapy Amenable to radiologic imaging
techniques No clinically apparent CNS metastases or carcinomatous meningitis

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life
expectancy: At least 12 weeks Hematopoietic: Absolute neutrophil count at least 1,500/mm3
Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 times upper
limit of normal (ULN) AST and ALT no greater than 3 times ULN Albumin greater than 2.5
g/dL No history of Gilbert's syndrome Renal: Creatinine no greater than 1.5 times ULN
Other: No other malignancy within the past 5 years except adequately treated basal cell or
squamous cell skin cancer or carcinoma in situ of the cervix No other severe disease,
infection, or comorbidity that would preclude study participation No known defect of
glutathione metabolism Not pregnant or nursing Negative pregnancy test Fertile patients
must use effective contraception during and for 3 months after study

PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent immunotherapy or therapeutic
biologic response modifiers No concurrent routine or prophylactic filgrastim (G-CSF) or
sargramostim No concurrent epoetin alfa Chemotherapy: See Disease Characteristics At least
4 weeks since prior chemotherapy (6 weeks for mitomycin or nitrosoureas) and recovered No
other concurrent cytotoxic chemotherapy Endocrine therapy: No concurrent hormonal therapy
for NSCLC Radiotherapy: See Disease Characteristics At least 2 weeks since prior
limited-field radiotherapy not involving the hematopoietic bone marrow and recovered At
least 4 weeks since prior radiotherapy to no more than 25% of the hematopoietic bone
marrow and recovered No prior wide-field radiotherapy to the pelvis No concurrent
radiotherapy (including palliative radiotherapy) Surgery: At least 4 weeks since prior
major surgery Other: At least 4 weeks since prior investigational agents No concurrent
anticonvulsants unless required for study drug-related toxicity No concurrent high-dose
acetaminophen (i.e., at least 4 g/day) No other concurrent investigational agents