Chemotherapy Without SCT for Myelodysplastic Syndromes

This content has been reviewed and approved by

Hagop M. Kantarjian, MD
Chairman & Professor, Leukemia Department
MD Anderson Cancer Center
University of Texas

Patients with myelodysplastic syndromes (MDS) who are unable or unwilling to undergo a stem cell transplant using donor cells or those planning to have their own stem cells collected for a future transplant can receive conventional chemotherapy without stem cell support. Although many patients have a remission with this type of treatment, most ultimately experience disease progression. While some patients may experience a long remission following therapy, remissions after conventional chemotherapy typically average less than 12 months. 

Because most patients with MDS are over 65 and cannot tolerate the side effects of conventional chemotherapy, lower doses of chemotherapy may be beneficial. 

Dacogen™ (decitabine) - A clinical trial has shown that patients treated with decitabine experienced significantly higher response rates and longer time to disease progression—defined as transformation AML or death—compared with patients who received supportive care. Patients who had not received prior treatment and those with intermediate 2 to high-risk disease received the most benefit from decitabine. Patients in this study only received three courses of decitabine. More recent findings, however, suggest that a better response may be possible with multiple courses of therapy. Decitabine was approved by the FDA for the treatment of MDS in 2006. 

Vidaza® (azacitidine) - In 2004, the FDA approved azacitidine for the treatment of MDS. Vidaza is the first drug to be approved specifically for the treatment of MDS. 

Results of a clinical trial that compared azacitidine to supportive care in the treatment of 191 patients with MDS demonstrated that the patients treated with azacitidine experienced more anticancer responses and were less likely to develop AML compared with patients who received supportive care. 

Among patients treated with azacitidine, 15.7 percent had an anticancer response whereas none of the patients who received supportive care had a response. Following treatment with azacitidine, all patients who responded to treatment and had previously required blood transfusions no longer required the transfusions to maintain appropriate hemoglobin levels. 

Patients who received azacitidine experienced an improved quality of life compared with those receiving supportive care. 

A recent study from Europe compared azacitidine  to best standard of care in 358 patients with intermediate 2 - high risk MDS. Azacitidine was associated with a significantly better survival (median survival 24 months with azacitidine versus 15 months for best supportive care; p = 0.0001).

Fludara®  (fludarabine) plus Cytosar®  (  cytarabine) - Chemotherapy regimen consisting of fludarabine and cytarabine with the white blood cell growth factor Neupogen® (filgrastim), produced remission in three-quarters of patients with advanced MDS.

Hycamtin® (topotecan) and cytarabine may be more tolerable than standard Idamycin® (darubicin) and cytarabine - A clinical study that involved 510 patients and compared four different chemotherapy combinations has revealed that anticancer responses and duration of survival were the same for all four treatments. However, treatment with topotecan and cytarabine resulted in fewer deaths than other regimens and may be considered an alternative to the standard idarubicin and cytarabine combination for the treatment of patients with progressive or high-risk MDS. 

Strategies to Improve Chemotherapy Without Stem Cell Transplant for MDS 

The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. 

Future progress in the treatment of MDS will result from the continued evaluation of new treatments in clinical trials. Participation in a clinical trial may offer patients access to better treatments and advance the existing knowledge about treatment of this cancer. Patients who are interested in participating in a clinical trial should discuss the risks and benefits of clinical trials with their physician. Areas of active investigation aimed at improving the treatment of MDS include the following: 

• Hycamtin® (topotecan) 
• Clofarabine and troxacitabine, among others.