The MDS Beacon™

The combination therapy of Vidaza (azacitidine) and thalidomide (Thalomid) did not lead to any unexpected side effects in myelodysplastic syndromes (MDS) patients according to a study performed by Australian researchers.

The findings were presented as a poster at the American Society of Hematology meeting and exposition in December 2009.

The Australian study followed results published in 2008 which showed that treating MDS and AML patients with Vidaza and thalidomide was as effective as treating high-risk patients with Vidaza alone (see related Beacon news). 

The Australian researchers stated that since there had been limited experience with this combination treatment so far, they investigated the combination treatment further to see if side effects impacted its tolerability.

For their study, the researchers enrolled a total of 80 MDS patients. Fourty one of these patients received treatment between July 2008 and July 2009 and have been evaluated for results.  Participants were required to be first-time recipients of thalidomide or any of its derivatives and Vidaza or any other demethylating agents. 

Of the 41 MDS patients evaluated, 12 percent were identified as low-risk, 37 percent as intermediate-1, 34 percent as intermediate-2, and 12 percent as high-risk.

Each patient received 50 mg thalidomide daily for four weeks at which point the dose was increased to 100 mg per day, and administered continuously for a maximum of 12 months. In addition, patients received 75mg/m² Vidaza per day for seven consecutive days every four weeks.  Treatment was stopped or reduced if patients experienced disease progression or excessive side effects due to toxicity. 

Fourteen patients, or 34 percent, remained on the thalidomide and Vidaza throughout the entire treatment period. These patients experienced median exposure times of 209 days to thalidomide and seven cycles of Vidaza.

Sixty six percent of patients discontinued thalidomide during treatment after a median of 49 days, while 59 percent discontinued Vidaza after a median of two cycles. 

During the first treatment cycle, 13 patients experienced severe side effects, most of which were infection-related. The risk of developing infections was increased in patients older than 65 years, patients with low white blood cell counts, and patients with restricted physical activity.

Researchers did not observe severe peripheral neuropathy (nerve damage in the limbs), a common side effect of thalidomide, in any of the 41 patients.

The study authors concluded that the combination therapy of Vidaza and thalidomide can be used to treat MDS without unexpected side effects altough infections were common in the first cycle of combination therapy. The study authors pointed out that infections are a recognized risk associated with MDS and Vidaza as a single-agent treatment and were therefore not unexpected. 

For more information, see abstract 1749 on the 2009 ASH meeting Web site.