JPH203 (KYT-0353) selectively inhibits L-type amino acid transporter LAT1-dependent L-leucine uptake and growth in HT-29 and human LAT1-expressing S2 murine renal proximal tubule cell cultures, but not human LAT2-expressing S2 cells (IC50/GI50 = 0.06/4.1, 0.14/16.4, and >10/>1000 μM, respectively). When administered via intravenous injection (6.3-25 mg/kg/d from d0 to d13), JPH203 effectively inhibits HT-29-derived tumor growth in mice in vivo.
