reports of the efficacy of thalidomide (Thalomid) as initial therapy for
multiple myeloma have been confirmed by researchers at The University of Texas
M.D. Anderson Cancer Center, Donna Weber, MD, reported at a symposium sponsored
by the University of Pennsylvania and the Multiple Myeloma Research Foundation.
As sole therapy, thalidomide brought about partial
remissions in one third of patients with asymptomatic, previously untreated
multiple myeloma at high risk of progression. A combined thalidomide/dexamethasone
regimen resulted in responses in more than 70% of patients with symptomatic,
previously untreated multiple myeloma, including some
complete remissions. These M.D. Anderson results are virtually identical to
those previously reported by researchers at the Mayo Clinic.
Remissions produced by either single-agent or combined
regimens have been long lasting, and the regimens have the additional advantage
of not interfering with subsequent stem cell collection, said Dr. Weber,
assistant professor, Department of Lymphoma and Myeloma.
Although final conclusions must await completion of a
randomized, controlled trial, combined thalidomide/dexamethasone appears to be
among the most active regimens in previously untreated multiple myeloma, she
said. Its efficacy approaches that of VAD (vincristine/Adriamycin/dexamethasone)
chemotherapy regimens, whose delivery requires an indwelling catheter.
"I feel this oral regimen [thalidomide/dexamethasone] may
well be the treatment of choice for previously untreated patients with
symptomatic multiple myeloma," Dr. Weber said. A controlled trial of
thalidomide/dexamethasone is currently being conducted by the Eastern
Collaborative Oncology Group (ECOG).
Researchers studying thalidomide in untreated multiple
myeloma have applied many lessons learned in previous studies in refractory
disease. In these patients, research from multiple centers has shown fairly
uniform response rates of about one third for thalidomide regimens and 40% to
50% for thalidomide/dexamethasone (with response defined as a 50% or greater
reduction in serum monoclonal paraprotein, a disease marker).