Selinexor, in addition to bortezomib and low-dose dexamethasone, is in clinical development for the treatment of adults with relapsed or refractory multiple myeloma (RRMM) who have received 1 to 3 prior therapies. MM is a rare, incurable cancer of the plasma cells in the bone marrow where large amounts of abnormal plasma cells are produced and interfere with the production of red and white blood cells and platelets. People with MM will experience periods of time without symptoms followed by periods when the illness comes back (‘relapsed’ MM). Eventually, the periods without symptoms will shorten and the illness will become immune to the drugs given to treat it (‘refractory’ MM).
Selinexor is the first in a new family of drugs known as selective inhibition of nuclear export (SINE) compounds that blocks a protein called XPO1. By blocking XPO1, Selinexor blocks the nuclear export of tumour suppressor, growth regulatory, and anti-inflammatory proteins, leading to accumulation of these proteins in the nucleus and enhancing their anti-cancer activity in the cell. Bortezomib and low-dose dexamethasone are already currently used in progressive MM. If licensed, the addition of Selinexor to bortezomib and low-dose dexamethasone would increase the treatment options for RRMM, a patient group with clear unmet need.