Preclinical Evaluation of RMS Therapies

(Preclinical Phase I) Non-tumor bearing athymic nude mice were used for tolerability testing of the following combinations: VCR + IRN, AZD1775 + VCR + IRN, and panobinostat + bortezomib. Mice were given 4 cycles of chemotherapy with 21 days per cycle. The chemotherapeutic drug combinations and schedule used were designed to mimic potential human clinical trials. Each treatment group contained 3 mice. Vincristine was dosed by intraperitoneal injection once a week on days 1, 8, and 15. Irinotecan was dosed by intraperitoneal injection once daily on days 1–5 and 8–12. AZD1775 was dosed by oral gavage twice daily on days 1–5. Panobinostat was dosed by intraperitoneal injection once daily on days 1, 3, 5, 8, 10 and 12. Bortezomib was dosed by intraperitoneal injection once daily on days 1, 4, 8 and 11. Mouse weight and standard complete blood counts were monitored for each treatment group. The health of the animals was monitored daily throughout therapy. (Preclinical Phase II) RMS orthotopic xenografts were created by injecting luciferase labeled cells from SJRHB000026_X1 (ERMS), SJRHB012_Y (ERMS), and SJRHB013759_X1 (ARMS) into recipient CD-1 nude mice using the intramuscular injection technique previously described. Mice were screened weekly by Xenogen and the bioluminescence was measured. Mice were enrolled in the study after achieving a target bioluminescence signal of 10⁶ –10⁷ photons/sec/cm² or greater for 2 weeks or a palpable tumor, and chemotherapy was started the following Monday. The following preclinical phase II trials were performed (Table S10):