Interleukin-12 and Trastuzumab in Treating Patients With Cancer That Has High Levels of HER2/Neu

OBJECTIVES: I. Determine the maximum tolerated dose of interleukin-12 (IL-12) when combined with trastuzumab in patients with HER2-Neu overexpressing malignancies. II. Determine the safety of this regimen in these patients. III. Analyze any expression of interferon-inducible genes in tumor tissues of these patients after receiving this regimen. IV. Characterize natural killer cytokine production in patients treated with this regimen. V. Determine serum interferon gamma levels in patients treated with this regimen. OUTLINE: This is a dose escalation study of interleukin-12 (IL-12). Patients receive an initial loading dose of trastuzumab IV over 90 minutes on day 1 of the first week and a maintenance dose of trastuzumab IV over 30-90 minutes on day 1 of each subsequent week. Patients receive IL-12 IV on days 2 and 5 beginning on week 3. Treatment with maintenance trastuzumab and IL-12 repeats weekly for 14 weeks in the absence of disease progression or unacceptable toxicity. Patients with stable or responding disease continue treatment for up to 38 additional weeks. Cohorts of 3-6 patients receive escalating doses of IL-12 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients experience dose limiting toxicity. Patients are followed every 3 months for 1 year and then every 6 months thereafter for survival. PROJECTED ACCRUAL: A total of 15 patients will be accrued for this study within 6 months.