PRIOR CONCURRENT THERAPY: Biologic therapy: Recovered from prior immunotherapy No concurrent prophylactic filgrastim (G-CSF) or sargramostim (GM-CSF) Chemotherapy: See Disease Characteristics At least 4 weeks since prior chemotherapy and recovered No other concurrent local or systemic chemotherapy Endocrine therapy: Not specified Radiotherapy: Recovered from prior radiotherapy No concurrent palliative or primary radiotherapy Surgery: Not specified Other: At least 30 days since other prior investigational drugs No other concurrent investigational drugs No concurrent participation in another clinical trial