Inclusion Criteria:

- Histo-cytologically proven SCLC

- Limited disease at diagnosis

- Age greater than or equal to 18

- Patients with a clinical response of CR or PR to first line combined modality
therapy

- KPS greater than or equal to 60

- Adequate bone marrow, liver and heart functions

- Written informed Consent

Exclusion Criteria:

- Prior surgical treatment for SCLC

- History of tuberculosis

- NCIC CTG grade 3 local skin toxicity reaction (ulceration) to > IU PPD test > 5 IU

- HIV positive

- Splenectomy or spleen radiation therapy in medical history

- Prior therapy to proteins of murine origin

- Any second line therapy for SCLC

- Investigational agent or immune therapy within 4 weeks prior to study randomization

- Severe active infections

- Active infections requiring systemic antibiotics, antiviral, or antifungal treatments

- Serious unstable chronic illness

- The use of systemic anti-histamines, NSAID or systemic corticosteroids

- Any previous malignancy except adequately treated CIS of the cervix or non melanoma
skin cancer or if previous malignancy was more than 5 years prior and there are no
signs of recurrence

- Pregnancy or breast feeding or absence of adequate contraception for fertile patients

- Any psychological, familial, sociological or geographical condition potentially
hampering compliance with the study protocol and follow-up schedule; those conditions
should be assessed with the patient before randomization in the trial.