Overview

Selinexor 20 mg is a first-in-class inhibitor of the nuclear export protein XPO1, a mechanism distinct from proteasome or IMiD drugs, which makes it valuable in combination regimens after multiple prior myeloma lines. Its novelty lies in blocking a trafficking step that other agents leave untouched.

How It Works

XPO1 (exportin 1) shuttles tumor-suppressor and growth-regulatory proteins out of the nucleus. Selinexor binds a cysteine residue in XPO1, trapping these proteins inside the nucleus where they can suppress proliferation and promote apoptosis. Because this exportin blockade is orthogonal to proteasome inhibition and immunomodulation, it retains activity in myeloma that has become refractory to those classes, enabling rational combinations.

Indications

Selinexor is indicated with dexamethasone for relapsed or refractory multiple myeloma after at least four prior therapies, and in combination with bortezomib and dexamethasone in earlier relapsed settings. Its role is therefore combination-based, targeting heavily pretreated disease where single agents fail. Given the heavily pretreated setting, cytopenias require monitoring that pharmacy should plan alongside the drug. Retaining nuclear tumor suppressors also sensitizes myeloma cells to partner agents, which is why Selinexor is scheduled around bortezomib rather than replacing it.

Dosage & Administration

The oral tablet strength is 20 mg, taken on specific weekly or twice-weekly schedules with food and antiemetic support, with each box containing 16 tablets. Combination cycles require alignment with partner drugs, so pharmacies should plan both Selinexor and the companion agent together to keep the regimen on schedule.

Storage & Sourcing

Store tablets below 30°C in the original blister, dry and away from light. As an oral agent it avoids cold chain, but humidity control and expiry rotation remain important because dosing is intermittent and stock may sit between cycles. Expiry-aware ordering prevents waste during the off weeks of the intermittent schedule and keeps the 16-tablet boxes aligned with real refill demand.

FAQ

Q: What is unique about the Selinexor mechanism? A: It inhibits XPO1 nuclear export, a step no proteasome or IMiD drug targets, so it works even when myeloma is refractory to those classes.

Q: Why is Selinexor given in combination rather than alone? A: In relapsed myeloma it is paired with dexamethasone or bortezomib to deepen response, since the exportin blockade complements their distinct mechanisms.

Q: How does the 20 mg strength fit intermittent dosing? A: The 16-tablet box supports the on-off weekly schedule with antiemetic cover, and pharmacies align it with the partner drug to keep combination cycles synchronized.