On March 31, 2021, the Food and Drug Administration (FDA) approved using the drug isatuximab-irfc to treat adult patients with relapsed or refractory multiple myeloma. The drug is approved for use in combination with two other drugs, carfilzomib and dexamethasone, and will be given to patients who have previously received one to three lines of therapy.
What is Myeloma?
Myeloma is a cancer of the plasma cells, the white blood cells in your bone marrow that create antibodies to protect you from infection. As with other cancers, the cells begin to reproduce abnormally and, in the process, crowd out normal cells in your bone marrow.
Causes, Risk Factors, and Symptoms
Research is still ongoing as to what causes myeloma to develop. However, it tends to be more commonly diagnosed in patients over 45. It is more common for men to be diagnosed with myeloma than it is for women. It is twice as common among black people as it is among white people.
Similar to many cancers, myeloma does not typically have any apparent symptoms. It is mainly diagnosed when higher than normal levels of protein are found in your blood. In more advanced cases, patients may experience bone pain, frequent infections, and bones that break easily, among other symptoms.
Myeloma remains an incurable disease, so any treatments are more about managing the cancer or remission. Treatment methods for myeloma might be based on several factors, including how and where the cancer has developed and its stage. These can range from radiation therapy to surgery to stem cell transplants.
Patients have also been prescribed various drugs to treat myeloma. These include chemotherapy drugs, steroids, immunomodulating agents, and antibody drugs, as well others. Doctors, however, often prefer to prescribe at least two or three different kinds of drugs as they believe the cancer responds better to this option than to single-drug treatment.
Isatuximab-irfc is a laboratory-made antibody drug designed to behave like a naturally occurring antibody, binding to a specific protein on targeted cells. With myeloma, the drug targets the protein CD38, which is more commonly found on myeloma cells than it is on normal cells. It is then able to kill the cells directly and recruit other immune system cells to assist it.
Until now, isatuximab-irfc was prescribed with pomalidomide, an immunomodulating drug, and dexamethasone, a steroid that is one of the most frequently used medications to treat myeloma. This combination is used to treat myeloma patients who have previously received at least two alternative treatments.
How the new drug combination will help treatment
As myeloma remains an incurable disease, any drug therapies are used until the cancer progresses or drug toxicity levels become too high. Therefore, adding new drug therapies to the treatment options is critical.
In the trial that led to its approval by the FDA, it was found that isatuximab-irfc plus carfilzomib and dexamethasone reduced the risk of the cancer either getting worse or a patient dying by 45%, compared with a treatment of just carfilzomib plus dexamethasone. The approval was made for myeloma patients whose cancer had returned or had not responded to treatment after one to three other therapies.