Pomalyst Plus Low-Dose Dexamethasone for Relapsed/Refractory Multiple Myeloma

The combination of Pomalyst® (pomalidomide) and low-dose dexamethasone was associated with significantly prolonged progression-free survival and overall survival compared with high-dose dexamethasone in patients with refractory or relapsed and refractory multiple myeloma, according to the results of a study published early online in the Lancet Oncology.

Multiple myeloma is a cancer of plasma cells, which are a special type of white blood cell that are part of the body’s immune system. Patients with multiple myeloma have increased numbers of abnormal plasma cells that may produce increased quantities of dysfunctional antibodies detectable in the blood and/or urine. Patients with multiple myeloma who have become refractory—or resistant—to the drugs Revlimid® (lenalidomide) and Velcade® (bortezomib) have limited treatment options. There is no standard treatment for these patients and they typically have a poor prognosis, with a median overall survival of 9 months.

Pomalyst is an immunomodulatory drug that has shown activity in multiple myeloma patients who have become refractory to Velcade®, Thalomid® (thalidomide), and Revlimid®. It works by directly inhibiting angiogenesis and myeloma cell growth. Pomalyst is delivered as an oral pill and it causes the body’s immune system to destroy cancerous cells and inhibit their growth. It is intended for patients who have received at least two prior therapies and whose disease did not respond to treatment and progressed within 60 days of the last treatment (relapsed and refractory).

Pomalyst alone has shown limited efficacy in patients with relapsed multiple myeloma, but synergistic effects have been noted when combined with dexamethasone. Researchers compared the efficacy and safety of Pomalyst plus low-dose dexamethasone with high-dose dexamethasone alone in these patients. The multi-national open-label trial included 455 patients with refractory or relapsed/refractory multiple myeloma. Patients were randomly assigned to receive Pomalyst plus low-dose dexamethasone or high-dose dexamethasone alone. In order to be eligible, patients must have received at least two previous treatments of Revlimid® (lenalidomide) and Velcade® (bortezomib) that failed.

After a median follow-up of 10.0 months, median progression-free survival (PFS) was 4.0 months in the Pomalyst group versus 1.9 months in the control group. Subgroup analysis revealed that median PFS was significantly longer in the Pomalyst group regardless of previous treatment. Median overall survival was also significantly longer in the Pomalyst group, 12.7 months versus 8.1 months. The overall response rate in the Pomalyst/low-dose dexamethasone group was 31 percent, compared to 10 percent in the high-dose dexamethasone group.

The most common grade 3 or 4 hematologic adverse events in the Pomalyst versus high-dose dexamethasone groups were neutropenia (48% vs 16%), anemia (33% vs 37%), and thrombocytopenia (22% vs 26%). Grade 3 or 4 nonhematologic adverse events included pneumonia (13% vs 8%), bone pain (7% vs 5%), and fatigue (5% vs 6%); grade 3 or higher febrile neutropenia occurred in 10% vs < 1% of patients.

In the Pomalyst group, 67 percent of patients required dose interruptions and 27 percent required dose reductions, compared with 28 percent and 32 percent in the high-dose dexamethasone group, respectively.

The researchers concluded that Pomalyst plus low-dose dexamethasone should be considered a new treatment option for relapsed/refractory multiple myeloma.

 

Reference:

San Miguel J, Weisel K, Moreau P, et al. Pomalidomide plus low-dose dexamethasone versus high-dose dexamethasone alone for patients with relapsed and refractory multiple myeloma (MM-003): a randomised, open-label, phase 3 trial. Lancet Oncology. Published early online September 3, 2013. doi:10.1016/S1470-2045(13)70380-2

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