NCIt definition : A prodrug of netupitant, a selective neurokinin 1 receptor (NK1R; TACR1) antagonist,
with potential antiemetic activity. Upon intravenous administration, fosnetupitant
is converted by phosphatases to its active form netupitant. Netupitant competitively
binds to and blocks the activity of NK1Rs in the central nervous system (CNS), by
inhibiting binding of the endogenous tachykinin-derived neuropeptide substance P (SP)
to NK1R. This prevents delayed emesis, which is associated with SP secretion. This
may prevent chemotherapy-induced nausea and vomiting (CINV).;