Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed diagnosis of extensive-stage small cell lung cancer (SCLC)

- No mixed histology

- Presence of ≥ 1 neuroendocrine marker (synaptophysin, chromogranin, or CD56) in tumor
tissue

- Achieved partial response (PR), complete response (CR), or stable disease (SD) ≤ 12
weeks of completing 4-6 courses of platinum-based chemotherapy regimen for
extensive-stage SCLC

- Patients with PR or SD must have measurable disease, defined as ≥ 1 lesion whose
longest diameter can be accurately measured as ≥ 2.0 cm but < 10 cm by chest
x-ray OR as ≥ 1.0 cm but < 10 cm by CT scan, CT component of a PET/CT scan, or
MRI

- If CT scan is used, it must be used for both pre- and post-treatment tumor
assessments

- Measurable disease is not required for patients with CR

- Brain metastases allowed provided they have been stable for ≥ 4 weeks after
completion of prior radiotherapy

PATIENT CHARACTERISTICS:

- ECOG performance status 0 or 1

- Life expectancy of ≥ 8 weeks

- ANC ≥ 1,500/μL

- Platelet count ≥ 100,000/μL

- Hemoglobin ≥ 9 g/dL

- Total bilirubin ≤ 1.5 times upper limit of normal (ULN) OR direct bilirubin normal

- AST ≤ 3 times ULN (≤ 5 times ULN if liver has tumor involvement)

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use adequate contraception

- Able to comply with study procedures to minimize virus exposure to others

- Willing to provide required biologic specimens

- Willing to return to NCCTG/CTSU enrolling institution for follow-up

- Adequate lung function (i.e., not oxygen dependent)

- The patient is eligible if not on a 24-hour oxygen schedule

- No second primary malignancy within the past 5 years, except for the following:

- Carcinoma in situ of the cervix

- Non-melanomatous skin cancer

- History of low-grade (Gleason score ≤ 6) localized prostate cancer (even if
diagnosed < 5 years prior to study entry)

- Stage I breast cancer that was treated ≥ 5 years before study entry

- Transitional cell carcinoma of the bladder (in situ)

- No active hepatitis B or hepatitis C

- No clinically significant infection

- No significant traumatic injury within the past 4 weeks

- No concurrent uncontrolled illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situation that would limit compliance with
study requirements

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- More than 4 weeks since prior radiotherapy (2 weeks for palliative radiotherapy to
skeletal metastases)

- Other prior radiation therapy (including WBRT, PCI, or Gamma Knife) is permitted as
long as the following are true:

- Recovered from prior radiotherapy (alopecia allowed)

- No prior consolidation radiation therapy to the chest

- No prior radiotherapy to > 25% of bone marrow

- For patients without brain metastases, WBRT or standard of care PCI completed ≥
2 weeks before administration of NTX- 010/placebo

- More than 365 days since prior immunotherapy or biologic therapy

- More than 4 weeks since prior major surgery* (i.e., laparotomy) or open biopsy

- More than 2 weeks since prior minor surgery*

- No prior exposure to the Seneca Valley virus (NTX-010), as determined by negative
serum antibodies

- No concurrent combination antiretroviral therapy for HIV-positive patients NOTE:
*Insertion of a vascular access device is not considered major or minor surgery.