Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically or cytologically proven limited stage small cell
lung cancer (SCLC) Must have completed adequate first-line combined modality treatment
comprising at least 4-6 courses of a 2-drug chemotherapy regimen and chest radiotherapy No
evidence of disease progression or relapse Disease response (complete or partial) after
treatment

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life
expectancy: Not specified Hematopoietic: WBC greater that 3,000/mm3 Platelet count greater
than 100,000/mm3 Hepatic: AST less than 1.5 times upper limit of normal Hepatitis B
negative Renal: Not specified Cardiovascular: Adequate cardiac function Other: HIV
negative Not pregnant or nursing Fertile patients must use effective contraception No
prior malignancy within 5 years except adequately treated nonmelanomatous skin cancer or
carcinoma in situ of the cervix No history of tuberculosis No grade 3 local skin toxicity
reaction (ulceration) to 5 IU or greater of PPD test No active infections requiring
systemic antibiotics, antiviral, or antifungal treatments No serious unstable chronic
illnesses No psychological, familial, sociological, or geographical condition that would
preclude study

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior therapy with proteins of murine
origin At least one month since prior immunotherapy No other concurrent immunotherapy
Chemotherapy: See Disease Characteristics No concurrent chemotherapy Endocrine therapy: No
concurrent chronic use of systemic corticosteroids Radiotherapy: See Disease
Characteristics No concurrent radiotherapy including prophylactic cranial irradiation No
prior spleen radiotherapy Surgery: No prior surgery for SCLC No prior splenectomy Other:
No prior second-line therapy for SCLC At least one month since prior investigational
agents No concurrent chronic use of systemic antihistamines or nonsteroidal
anti-inflammatory drugs No concurrent immunosuppressive therapy