The usual treatment approach for patients with multiple myeloma who have had chemotherapy with a stem cell transplant—a procedure that uses a person’s own healthy blood stem cells to replace diseased or damaged bone marrow—is maintenance therapy with a drug called lenalidomide. Lenalidomide (brand name Revlimid®) stimulates the body’s immune system to recognize and destroy myeloma cells, and it prevents new myeloma cells from forming. Currently, it is the only myeloma treatment approved by the Food and Drug Administration (FDA) for maintenance therapy after a stem cell transplant. There is no set time for the ideal duration of maintenance lenalidomide. However, even with this treatment, the average length of time a patient lives before their cancer returns or grows is about four years.
One way doctors can tell if the lenalidomide is working is to look for minimal residual disease (MRD). MRD testing helps doctors see if a cancer treatment is effective and identify patients who may be at risk of their cancer returning. Doctors perform a biopsy to collect blood or bone marrow samples, then look at them under a microscope to find any remaining cancer cells. Typically, patients who do not have any remaining cancer cells (MRD negative) have longer remissions and potentially longer survival than those with remaining cancer cells (MRD positive).
The OPTIMUM clinical trial (EAA171) is for patients who are MRD positive after approximately one year of lenalidomide maintenance therapy following a stem cell transplant. OPTIMUM is exploring an additional treatment for these patients who are at higher risk of their cancer returning. By adding the drug ixazomib to lenalidomide maintenance therapy, researchers hope to improve outcomes for this group.
OPTIMUM uses MRD testing as a screening tool, which requires a bone marrow biopsy as the first step in the trial. Patients who are MRD negative will leave the study. Patients who are MRD positive will remain in the trial and be randomly assigned by a computer to one of two treatment groups. The first group will get the usual treatment, lenalidomide, plus the study drug, ixazomib. Both drugs are oral, meaning pills to take by mouth. The second group will get the usual treatment, lenalidomide, plus a placebo pill. A placebo is a capsule that looks like the study drug, but contains no medication. The use of placebos in clinical trials helps prevent bias. Placebos are never used in place of cancer treatment.
Doctors will look to see if the usual treatment plus the study drug increases the survival of patients compared to the usual approach. They will follow all patients for up to 10 years to watch for side effects and monitor overall health.
The FDA already approved ixazomib for use in combination with lenalidomide and dexamethasone for patients with multiple myeloma who have received at least one prior therapy.
This study is led by Shaji Kumar, MD of Mayo Clinic.
Learn more about OPTIMUM (EAA171) at ecog-acrin.org.