CHS 828 inhibits neuroblastoma growth in mice alone and in combination with antiangiogenic drugs.

CHS 828 is a new chemotherapeutic drug, a pyridyl cyanoguanidine. CHS 828 has low toxicity and lacks known patterns of multidrug resistance. Here we report that oral, daily treatment with CHS 828 reduced the growth of SH-SY5Y human neuroblastoma tumors in male NMRI nu/nu mice by 82% without apparent toxicity. CHS 828 induced complete tumor regression for at least 5 weeks in four of nine animals (44%). Combination therapy with CHS 828 and the antiangiogenic drugs TNP-470 or SU5416 decreased neuroblastoma growth by a further 10 and 3%, respectively. Combination therapy induced tumor regression at d 4 with CHS plus TNP and d 6 with CHS plus SU5416, compared with d 14 with CHS 828 alone (p < 0.05), and complete tumor regression was seen in nine of 19 animals (47%). Combination treatment of CHS 828 and TNP-470 decreased the total viable tumor volume by 71% compared with treatment with CHS 828 alone. Our findings support CHS 828 as a promising new drug in treatment of childhood cancers. Furthermore, they imply efficiency of daily administration of nontoxic doses of chemotherapy, and a possible additive effect when chemotherapy is combined with angiogenesis inhibitors.