Lometrexol Plus Folic Acid in Treating Patients With Stage IIIB or Stage IV Non-Small Cell Lung Cancer

You may be eligible if

• DISEASE CHARACTERISTICS:
• Histologically confirmed non-small cell lung cancer (NSCLC)
• * Stage IIIB or IV
• * Squamous cell carcinoma
• * Adenocarcinoma
• * Large cell carcinoma
• * Adenosquamous carcinoma
• Progressive disease after receiving 1 cisplatin- or carboplatin-containing regimen for stage IIIB or IV disease
• Measurable disease
• * At least 1 lesion at least 1 cm x 1 cm by CT scan either not in a previously irradiated field or showing clear evidence of disease progression after radiation
• No symptomatic or rapidly increasing, moderate or large amounts of pleural effusion or ascites
• No prior or concurrent CNS metastases (brain or meningeal)
• PATIENT CHARACTERISTICS:
• Age:
• 18 and over
• Performance status:
• Karnofsky 70-100%
• Life expectancy:
• At least 3 months
• Hematopoietic:
• Absolute neutrophil count at least 1,500/mm\^3\*
• Platelet count at least 100,000/mm\^3\*
• Hemoglobin at least 9.0 g/dL\*
• \*Without transfusions or growth factors in the previous 7 days
• Hepatic:
• Bilirubin no greater than 1.5 times upper limit of normal (ULN) (regardless of liver involvement secondary to tumor)
• AST and ALT no greater than 2.5 times ULN (5 times ULN if liver has tumor involvement)
• Renal:
• Calculated creatinine clearance at least 60 mL/min using Cockroft and Gault formula
• Gastrointestinal:
• No inflammatory bowel disease
• No radiation enteritis
• No malabsorption syndrome
• No inability to absorb folic acid
• Other:
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during study
• No known untreated vitamin B12 deficiency
• HIV negative
• No drug abusers
• No prior malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix
• No severe concurrent disease or major comorbidity that would preclude study participation
• PRIOR CONCURRENT THERAPY:
• Biologic therapy:
• At least 3 weeks since prior biologic therapy for NSCLC and recovered from acute side effects
• Prior treatment with an experimental vaccine allowed
• No concurrent routine or prophylactic filgrastim (G-CSF), sargramostim (GM- CSF), or epoetin alfa
• Chemotherapy:
• See Disease Characteristics
• At least 3 weeks since prior chemotherapy for NSCLC (6 weeks for mitomycin or nitrosourea) and recovered from acute side effects
• Prior adjuvant or neoadjuvant chemotherapy allowed
• Endocrine therapy:
• Not specified
• Radiotherapy:
• See Disease Characteristics
• Recovered from acute side effects of prior radiotherapy
• No prior radiotherapy to 25% or more of bone marrow
• No prior whole pelvic irradiation
• Surgery:
• At least 3 weeks since prior major surgery and recovered
• Other:
• At least 3 weeks since prior investigational agent
• No concurrent proguanil, trimethoprim, co-trimoxazole, or pyrimethamine