PRIMARY OBJECTIVE:
I. Determine the efficacy of bortezomib, in terms of tumor response rate, in patients with metastatic papillary or follicular thyroid cancer unresponsive to prior radioiodine therapy.
SECONDARY OBJECTIVE:
I. Determine the clinical activity of this drug, in terms of progression-free survival, in patients treated with this drug.
OUTLINE: This is an open-label, multicenter study. Patients receive bortezomib IV over 3-5 seconds on days 1, 4, 8, and 11. Treatment repeats every 21 days for at least 4 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed periodically.