Matrix metalloproteinases (MMPs) are a class of membrane bound enzymes that are involved in the degradation of the extracellular matrix. MMP-2 and MMP-9 have been associated with the progression of cancer. It is hypothesized that an imbalance between MMPs and MMP inhibitors allows the destruction of the extracellular matrix and enhances the ability of the tumor cells to grow and metastasize. By inhibiting MMPs, it is thought that angiogenesis and metastasis can be inhibited. This is a phase I study of COL-3, an oral matrix metalloproteinase inhibitor, in patients with refractory metastatic cancer. COL-3 is a chemically modified tetracycline derivative. Patients must have clinically progressive disease documented within 1 month prior to entry to be eligible for treatment. Patients must have also failed therapy of proven efficacy for their disease and have an ECOG performance status of less than or equal to 2. Patients must be willing to travel from their home to the NIH for follow-up visits. Patients with brain metastases or primary CNS malignancies are not eligible. Concurrent therapy for their cancer (i.e., radiation therapy, chemotherapy, etc.) will preclude participation. We will be defining the maximum tolerated dose, the toxicity profile, characterizing the pharmacokinetics, and evaluating the effect of COL-3 on several biological endpoints.