Oral administration of NXP900 in a KYSE70 xenograft mouse model with YES1 gene amplification, resulted in an average decrease of tumor volume of 71% while in the vehicle control group tumor volume increased by 472% (p ≤ 0.001), demonstrating significant tumor regression. On Day 27, a mean increase from baseline in body weight of 2.0% and 3.5% was seen in the NXP900 and control groups respectively, indicating good tolerability...NXP900 has marked antitumor efficacy in esophageal carcinoma models in vitro and in vivo...