The MDS Beacon™

European researchers have found during a Phase 2 study that Revlimid (lenalidomide) produces an improved chromosomal response in High-risk myelodysplastic syndromes (MDS) patients. The results were presented today at the 51st annual American Society of Hematology (ASH) meeting.

Revlimid has already been used with Low- or Intermediate-1 risk MDS subtypes, especially those who require red blood cell transfusions or have del-5q, as it produces a high rate of transfusion independence and improved chromosomal abnormalities.

Patients with del-5q are missing the ‘q’ arm of chromosome 5.

Although the exact mechanism of Revlimid has yet to be fully characterized, it relieves symptoms of MDS by stimulating the immune system, causing cell death, and inhibiting new blood vessel growth.

Twenty High-risk MDS and acute myeloid leukemia (AML) patients, the majority of whom had del-5q, received varying doses of Revlimid over a median of 13 weeks. Doses varied incrementally from 10 mg to 30 mg, and maximum doses were administered for 8 weeks.

Patients’ chromosomal responses were evaluated 8 and 16 weeks after beginning treatments, while bone marrow responses were assessed every four weeks.

Although only seven patients were able to complete the entire 16 weeks of treatment, six achieved greater than 50 percent reduction of chromosomal abnormalities and one patient’s blast count decreased from 9.5 percent to less than 5 percent.

Thirteen patients did not complete the study; ten experienced severe side effects, including hospitalization due to infection or low white blood count, while three encountered disease progression.

Results showed 30 percent of the participating MDS or AML patients achieved at least partial chromosomal response, while 67 percent also reported improvement in blood cell development.

In addition, 15 patients experienced serious adverse events that led to inpatient hospitalization. Although six patients died from these events, cause of death was determined to be unrelated to Revlimid.

These results are similar to a previous study in the journal Blood, which reported 10 mg Revlimid per day for 21 consecutive days every four weeks improved blood cell development in High-risk MDS patients with del-5q.

This Phase 2 study was conducted with 47 patients, 27 percent of whom achieved at least partial response. Seven patients experienced complete remission, and overall median survival was 272 days.

Patients in this study did experience side effects such as low white blood cell or platelet counts; however, researchers were unable to find a correlation to the treatment, due to the high number of patients who presented such symptoms before receiving Revlimid.

In conclusion, Revlimid is promising treatment for High-risk MDS patients with del-5q, despite the frequency of side effects and infection.

Future clinical trials will likely test Revlimid in combination with other agents, including cytostatic or hypomethylating agents, to further improve patient responses.

For more information, please see abstract 115 at the ASH Meeting Web site.