According to a recent press release, pharmaceutical company Karyopharm Therapeutics Inc. (“Karyopharm”) achieved a milestone in the NEXPOVIO (selinexor) drug development process. The Committee for Medicinal Products for Human Use (CHMP), part of the European Medicines Agency (EMA), assigned a positive opinion to NEXPOVIO, in conjunction with dexamethasone, for patients with multiple myeloma. Specifically, NEXPOVIO is designed for patients with refractory multiple myeloma who have had their condition progress despite at least four previous treatments, including proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies.

NEXPOVIO

Marketed in the United States as XPOVIO, NEXPOVIO is an orally-administered, Selective Inhibitor of Nuclear Export (SINE) compound. It works by binding to exportin 1 (XPO1) and preventing the protein from properly functioning. Through this inhibition, it assists with tumor suppressing and anti-inflammatory measures, prompting a more effective anti-cancer response.

Although NEXPOVIO received a positive opinion, there is still work to do before the Marketing Authorization Application (MAA) is officially approved in Europe. However, a decision should be made by the end of April 2021. The MAA includes data from a Phase 2b STORM clinical trial. During the trial, researchers analyzed NEXPOVIO for patients with previously treated multiple myeloma. 122 patients enrolled. Patients had a median 7 prior treatments. Overall response rate was 26%, with a median overall survival (OS) rate of 15.6 months in patients who reached any response.

While the drug reached its endpoints, 58% of participants experienced severe reactions; these reactions were fatal in 9% of patients. Common side effects included:

• Diarrhea or constipation
• Nausea and vomiting
• Appetite loss
• Unintended weight loss
• Fatigue
• Hyponatremia (low sodium levels)
• Thrombocytopenia (low platelet counts)
• Anemia (low red blood cell count)
• Neutropenia and leukopenia (low white blood cell count)
• Shortness of breath
• Upper respiratory tract infections

Outside of the STORM trial, researchers are also evaluating NEXPOVIO as a potential treatment for liposarcoma and endometrial cancer.

Multiple Myeloma

While researchers are not sure exactly what causes multiple myeloma, a rare form of cancer developing in plasma cells, some believe a missing or damaged chromosome 13 could play a role. Normally, plasma cells create antibodies that help fight infection. But in multiple myeloma, unhealthy cancer cells crowd out healthy blood cells. They also produce M proteins, abnormal antibodies. Symptoms of multiple myeloma include:

• Appetite loss
• Fatigue
• Frequent infections
• Bone pain and weakness, which can be localized to the spine or chest
• Nausea and constipation
• Confusion
• Unintended weight loss
• Excessive thirst
• Low platelet and red/white blood cell counts
• Leg numbness and weakness
• Hypercalcemia (high levels of calcium in the blood)
• Kidney damage
• Spinal cord compression

Learn more about multiple myeloma.