FDA Approves New Oral Drug Iberdomide for Multiple Myeloma Patients
The U.S. Food and Drug Administration (FDA) recently granted accelerated approval to a new oral medication, iberdomide, for treating multiple myeloma in adults who have received at least one prior therapy. Developed by Bristol Myers Squibb and marketed as Zynlonta, the drug is designed to target malignant plasma cells in the bone marrow, a hallmark of multiple myeloma, a cancer of immune system cells. Dr. Yulia Waksman, head of the myeloma and amyloidosis service at Davidoff Hematology Center in Beilinson Hospital, explained that the disease causes uncontrolled plasma cell growth leading to bone marrow damage, anemia, kidney failure, and bone lesions.
Iberdomide is administered in combination with daratumumab (Darzalex), an antibody that helps the immune system attack myeloma cells, and the steroid dexamethasone. The oral administration offers patient convenience. The drug works by binding to cereblon, a protein involved in marking other proteins for degradation, thereby disrupting proteins essential for myeloma cell survival. This mechanism is part of a new class called CELMoD (Cereblon-Modulating Protein Degraders).
The FDA approval was based on a phase 3 clinical trial involving 939 patients with relapsed or refractory multiple myeloma after one or two prior treatments, including 13 patients from Israeli medical centers. Among 207 patients receiving the new combination, 41% achieved a complete response with no detectable cancer cells in bone marrow by sensitive minimal residual disease (MRD) testing, compared to 21% in the control group treated with daratumumab, dexamethasone, and bortezomib. This MRD negativity is linked to longer disease control but does not confirm a cure. This is the first FDA approval based on MRD results, marking a significant step in treatment options.
However, the approval is accelerated and contingent on ongoing studies to confirm long-term benefits such as progression delay or survival extension. Side effects include high rates of neutropenia (90.2%), infections (78.9%), serious infections (40%), and risks of blood clots, which require preventive measures. The drug carries warnings against use during pregnancy due to risks of fetal harm and thromboembolic events. It is currently unclear when iberdomide will be available in Israel or if it will be included in the national health basket next year.
