Patients receive gemcitabine IV over 30 minutes on days 1 and 8, carboplatin IV over 15-30 minutes on day 1, and bortezomib IV over 3-5 seconds on days 1, 4, 8, and 11. Treatment repeats every 21 days for up to 6 courses in the absence of disease progression or unacceptable toxicity. Patients with stable or responding disease may continue to receive bortezomib alone on the above schedule for up to 1 year at the discretion of the treating physician.