FDA warns of new malignancies with multiple myeloma treatment

FDA recently issued a warning about an increased risk of developing new cancers for patients taking lenalidomide (Revlimid, Celgene) for the treatment of multiple myeloma.

FDA reviewed clinical trials published after lenalidomide was approved, which found that newly-diagnosed patients with multiple myeloma had a significantly increased risk of developing second primary malignancies compared to patients who received a placebo. The studies showed an increased risk of developing acute myelogenous leukemia, myelodysplastic syndromes, and Hodgkin's lymphoma.

"Take into account both the potential benefit of Revlimid and the risk of second primary malignancies when considering treatment....[and] encourage patients to read the Medication Guide when they receive their Revlimid prescription," FDA stated in its safety announcement.

FDA reviewed 3 prospective, randomized trials in which patients with newly-diagnosed multiple myeloma received initial chemotherapy or chemotherapy plus blood stem cell transplantation followed by treatment with lenalidomide or a placebo.

A pooled analysis of the 3 ongoing trials showed 65 primary malignancies among 824 patients in the lenalidomide treatment arms compared to 19 second primary malignancies among 665 patients in the treatment group that did not include lenalidomide maintenance. "This difference is almost a 3-fold increase in new malignances for the groups receiving Revlimid versus the groups that did not receive Revlimid," FDA stated.

FDA also conducted a retrospective pooled analysis of second primary malignances from 2 clinical trials that supported FDA's initial approval of lenalidomide for relapsed multiple myeloma. The multicenter, parallel-group trials examined lenalidomide plus high-dose dexamethasone therapy versus dexamethasone alone in the treatment of patients with relapsed or refractory multiple myeloma. The incidence rates of developing a second primary malignancy during the treatment phase of these trials were 3.98 per 100 person-years for patients in the lenalidomide/dexamethasone group and 1.38 per 100 person-years for those in the placebo-dexamethasone groups.