Think of it as a biological nuclear export ban: A combination of the nuclear export protein inhibitor selinexor and dexamethasone was associated with relatively good objective response rates and clinical benefit rates among some patients with relapsed or refractory multiple myeloma (MM).
In the dose-expansion portion of a phase 1 dose-finding trial, the objective response rate (ORR) among 12 patients treated with selinexor 45 mg/m2 and 20 mg dexamethasone twice weekly was 50%, and the clinical benefit rate – a composite of complete responses, very good partial responses, partial responses and minimal responses – was 58%, reported Christine Chen, MD, of Princess Margaret Cancer Centre in Toronto, and her colleagues.
“Selinexor is an oral agent with a completely novel mechanism of action and anti-MM activity in combination with dexamethasone that could provide a new option for patients suffering from this incurable disease,” wrote Dr. Chen and her colleagues. The report was published in Blood.
Selinexor is a selective oral inhibitor of the cellular nuclear export protein exportin 1 (XPO1). Inhibition of this protein causes tumor suppressor proteins to accumulate in the nuclei of malignant cells, leading to programmed cell death (apoptosis) of malignant cells, but with minimal effects on normal cells.