High-dose glucocorticoid treatment of resistant myeloma.

Intermittent, high-dose dexamethasone treatment was given to 49 consecutive patients with refractory multiple myeloma. In patients who were unresponsive to previous treatment, the response rate of 27% was similar to that achieved with the VAD regimen, which combines the same schedule of dexamethasone with vincristine and doxorubicin given by continuous infusion. Among patients with relapses, VAD chemotherapy induced remissions in 11 of 17 patients (65%), whereas dexamethasone alone induced remissions in 4 of 19 (21%). The median survival of all patients responding to either treatment, 22 months, was longer than that from any previous program for treatment of resistant myeloma. These findings indicate the value of frequent dexamethasone administration in patients unresponsive to standard therapy and show the major role of vincristine and doxorubicin given by continuous infusion in patients with relapses. They also suggest different mechanisms for primary and secondary resistance to chemotherapy.