Research investigating the use of thalidomide
in multiple myeloma report that 34% of patients treated with the drug
experienced a reduction in tumor burden. Some patients experienced
more than a 7,500-fold reduction in tumor growth, including three who
approached a near complete response. In total, 89 patients
participated in the trial, all of whom had exhausted conventional
forms of therapy, including chemotherapy and bone marrow transplantation.
The data were presented at the 40th annual meeting of the American
Society of Hematology by Seema Singhal, MD, of the Myeloma and
Transplantation Research Center (MTRC) of the Arkansas Cancer
Research Center (ACRC), part of the University of Arkansas for
Medical Sciences, Little Rock.
All of the study participants had end-state refractory
(nonresponsive) multiple myeloma, said Dr. Singhal, and each one had
previously relapsed following treatments with other therapeutic
modalities, including 75 who had received one bone marrow transplant
and 56 who had had two prior transplants.
Findings Consistent With an Earlier Analysis
These recent findings are consistent with the results of an earlier
analysis of 26 patients, which determined that over half of all
patients with advanced disease developed either stable disease or
improved with thalidomide therapy. Current clinical trials at MTRC,
under the leadership of Bart Barlogie, MD, address the usefulness of
adding thalidomide to primary induction therapy for newly diagnosed
patients with myeloma, followed by tandem transplant and
Dr. Barlogie, the principal investigator of the thalidomide projects,
added: We are extremely pleased with the efficacy of
thalidomide in these patients that had failed all other
therapies. He also noted that thalidomide was also
effective in patients with high grade myeloma, including those who
had chromosome 13 deletion, which is usually refractory to high-dose
chemotherapy and transplantation. In addition, preliminary
results indicate that the combination of thalidomide and chemotherapy
appears to be effective in treating plasma cell leukemia and
fulminant multiple myeloma.
Studies are continuing at the ACRC to evaluate the potential role of
thalidomide in the treatment of multiple myeloma. Although
researchers have not identified the mechanism by which thalidomide
treats multiple myeloma, they suspect several actions are involved,
including the possibility that thalidomide suppresses tumor necrosis
factor-alpha production, and that it increases the bodys
production of interleukin-10. Dr. Barlogie also believes that
thalidomide works through antiangiogenesis, by preventing the growth
of vessels that nourish the malignant cells, especially since myeloma
is associated with increased blood vessel formation in the bone marrow.
Dr. Barlogie added that additional studies are beginning at the
MTRC, to evaluate the role of thalidomide in the treatment of acute
leukemia, amyloidosis, and Waldenströms macroglobulinemia,
a cancer closely related to multiple myeloma.