FDA Approves Zenbexus Combination for Multiple Myeloma

The FDA has approved Zenbexus (iberdomide) to treat adults with multiple myeloma. Multiple myeloma is a type of blood cancer that affects plasma cells in the bone marrow. It is used for people whose cancer has returned or stopped responding after they tried at least one other treatment. Zenbexus is given in combination with two other medicines called daratumumab and hyaluronidase-fihj, and dexamethasone.

This medicine works by targeting and breaking down specific proteins inside cancer cells. Lowering these protein levels helps stop cancer cells from growing and causes them to die. The medicine also helps boost your body’s immune system to fight the cancer cells better.

Why Was Zenbexus Approved?

The approval was based on a main clinical study involving 939 adults with multiple myeloma. Researchers looked at a main group of 420 people to see how well the treatments worked. Half of the group took Zenbexus with daratumumab and hyaluronidase-fihj and dexamethasone. The other half took a different combination treatment.

The main outcome looked at minimal residual disease, which measures whether tiny amounts of cancer cells remain after treatment. In the study, 41% of people taking the Zenbexus combination reached a complete response with no detectable cancer cells. In comparison, only 21% of people taking the other treatment combination reached this result.

The FDA granted accelerated approval based on these early cancer-clearing results. This pathway helps bring promising treatments to patients faster. Continued approval may depend on future study results confirming these clinical benefits.

What Do I Need to Know About Zenbexus?

Zenbexus comes as a capsule that you take by mouth once a day for 21 days of a 28-day cycle. Swallow the capsules whole with water. Do not open, break, or chew them. If you touch a broken capsule, wash your hands right away with soap and water.

This medicine carries serious risks and has a boxed warning for harm to a fetus and dangerous blood clots. Due to the risk of birth defects, you must not get pregnant while taking this drug. Zenbexus is only available through a special safety program called the Zenbexus REMS. Both women and men must follow strict birth control rules during treatment and for four weeks after the last dose. You must also avoid donating blood, sperm, or eggs during this time.

Zenbexus can cause serious blood clots in your legs, lungs, heart, or brain. Tell your healthcare provider right away if you have leg pain or swelling, sudden shortness of breath, chest pain, or sudden numbness. Zenbexus can also cause low white blood cell counts and severe infections. Contact your healthcare provider right away if you get a fever, chills, or other signs of an infection.

Other common side effects include upper respiratory infections, tiredness, muscle and joint pain, pneumonia, diarrhea, trouble controlling body movements, rashes, sleep problems, and constipation. Tell your healthcare provider about all medical conditions you have and all medicines you take. Certain medicines can interact with Zenbexus and change how it works. Do not breastfeed while taking this medicine.