The MDS Beacon™

Combination therapy of Revlimid (lenalidomide) and Vidaza (azacitidine) was effective and well tolerated in high-risk myelodysplastic syndromes (MDS) patients, according to a Phase 1 study performed by United States researchers.

Vidaza is approved in the U.S. for all types of MDS patients, generally delays progression of MDS to acute myeloid leukemia, and improves overall survival. Revlimid is typically used to treat certain low- or intermediate-1 risk MDS patients.

The Phase 1 study results represented attempts by researchers to determine the maximum tolerated dose and the tolerability of the combination treatment in high-risk MDS patients by testing different dosing schedules.

Researchers described the study results of the combination therapy as “encouraging clinical activity.”

However, researchers did not initially expect such a positive response by patients to the therapy.

“We were surprised for 2 reasons: We anticipated that the combination might be more toxic than either agent used alone. As it turns out, it was not. And we were surprised that the efficacy appeared to be at least as good, if not better than either agent used alone in higher-risk MDS,” said Dr. Mikkael Sekeres, lead author of the study.

Researchers also concluded that the most effective “go-forward” dosage regimen was 75 mg/m² on days 1 through 5 for Vidaza and 10 mg on days 1 through 21 for Revlimid.

The study included 18 patients with a median age of 68. Patients received treatment on a 28 day cycle, with patients receiving a maximum of seven cycles. Patient response was evaluated at a follow-up length of seven months.

The overall response rate was 67 percent, with 44 percent experiencing a complete response, 17 percent experiencing hematological improvement, and 6 percent experiencing complete response in the marrow.

This compares to a response rate of 45 percent for Vidaza alone and 20 percent for Revlimid alone in higher-risk MDS patients.

During the study, there were no hematological side effects that limited dosage, and a maximum-tolerated dose was not reached. Non-hematological side effects included severe or life-threatening febrile neutropenia (temporarily lowered white blood cell levels) in five patients, cardiac toxicity in two patients, and central nervous system hemorrhages in two patients.

Several other Phase 1 and Phase 2 trials are also investigating the combination of Vidaza and Revlimid for the treatment of MDS.

For more information, please see the study in the Journal of Clinical Oncology.