December 18, 2020
The U.S. FDA has approved a new indication for Xpovio® (selinexor), manufactured by Karyopharm. The drug is now indicated for use in combination with bortezomib and dexamethasone to treat multiple myeloma in adults who have received at least one prior therapy.
Multiple myeloma is a cancer that begins in plasma cells. As cancerous plasma cells build up in the body’s bone marrow, they leave no room for the healthy plasma cells that are needed to fight infections. The cancerous cells also produce abnormal proteins that can cause kidney damage and other problems over time. Multiple myeloma has an overall five-year survival rate of 52%.
In a clinical study, patients treated with Xpovio, bortezomib, and dexamethasone (SVd therapy) had a median progression free survival time of 13.9 months compared to 9.5 months for patients who received bortezomib and dexamethasone only (Vd therapy). SVd therapy produced a significantly higher rate of deep responses, defined as very good partial response or better, compared to Vd therapy (44.6% vs. 32.4%). It also had a longer median duration of response at 20.3 months compared to 12.9 months for Vd therapy. A higher proportion of patients on SVd therapy (17%) achieved a complete response or a stringent complete response compared to patients on Vd therapy (10%).
Recommended dosing under the new indication is 100mg taken by mouth once weekly, on the first day of each week, until disease progression or unacceptable toxicity occur.
First FDA approved in 2019, Xpovio is also indicated to treat relapsed or refractory multiple myeloma in certain adults who have received at least four prior therapies, and to treat relapsed or refractory diffuse large B-cell lymphoma (DLBCL), not otherwise specified, after at least two lines of systemic therapy.