Table 1.
In vivo activity of tazemetostat (EPZ-6438) against PPTP solid tumor lines.
| Line | Tumor Type | Estimate of Median Time to Event | P-value | EFS T/C | Median RTV/CD45 at End of Study | Tumor Volume T/C | Median Group Response | EFS Activity |
|---|---|---|---|---|---|---|---|---|
| KT-16 | Rhabdoid | > EP | <0.001 | > 5.6 | 3.7 | 0.48 | PD2 | Int |
| KT-14 | Rhabdoid | > EP | 0.008 | > 2.1 | 2.6 | 0.84 | PD2 | Int |
| KT-12 | Rhabdoid | > EP | 1 | . | 2.3 | 0.91 | NE | NE |
| NCH-RBD1 | Rhabdoid | > EP | 0.002 | > 1.4 | 3.4 | 0.82 | PD2 | NE |
| NCH-RBD2 | Rhabdoid | 10.4 | 0.486 | 0.9 | >4 | 1.17 | PD1 | Low |
| BT-16 | Rhabdoid (CNS) | 28.5 | 0.005 | 1.9 | >4 | 0.67 | PD2 | Low |
| G401 | Rhabdoid | > EP | <0.001 | > 4.4 | 1 | 0.7 | SD | High |
| KT-10 | Wilms | 14.9 | 0.203 | 1.1 | >4 | 0.85 | PD1 | Low |
| KT-13 | Wilms | 13.9 | 0.003 | 1.5 | >4 | 0.7 | PD2 | Low |
| EW5 | Ewing | 12.3 | 0.432 | 1 | >4 | 0.95 | PD1 | Low |
| EW8 | Ewing | 11.4 | 0.057 | 1.2 | >4 | 0.87 | PD1 | Low |
| TC-71 | Ewing | 14 | 0.104 | 1.1 | >4 | 0.78 | PD1 | Low |
| CHLA258 | Ewing | 12.5 | 0.12 | 1.1 | >4 | 0.95 | PD1 | Low |
| Rh10 | Alveolar RMS | 14.9 | 0.374 | 1.1 | >4 | 0.93 | PD1 | Low |
| Rh30 | Alveolar RMS | 12.7 | 0.131 | 1.1 | >4 | 0.81 | PD1 | Low |
| Rh41 | Alveolar RMS | 9.8 | 0.839 | 1 | >4 | 0.95 | PD1 | Low |
| Rh65 | Alveolar RMS | 29.1 | 0.024 | 0.8 | >4 | 0.77 | PD1 | Low |
| BT-50 | Medulloblastoma | > EP | 0.025 | > 1.6 | 3.5 | 0.9 | PD2 | NE |
| BT-36 | Ependymoma | 26.4 | 0.615 | 1 | >4 | 1.1 | PD1 | Low |
| BT-35 | Astrocytoma | 18.1 | 0.108 | 1.2 | >4 | 0.92 | PD1 | Low |
| BT-39 | Glioblastoma | 11.1 | 0.872 | 1.1 | >4 | 0.92 | PD1 | Low |
| BT-56 | Glioblastoma | 12 | 0.93 | 1 | >4 | 0.86 | PD1 | Low |
| NB-1691 | Neuroblastoma | 13.3 | 0.918 | 1.3 | >4 | 0.91 | PD1 | Low |
| NB-EBc1 | Neuroblastoma | 6.8 | 0.598 | 1 | >4 | 1.02 | PD1 | Low |
| NB-1643 | Neuroblastoma | 6.9 | 0.961 | 1 | >4 | 1 | PD1 | Low |
| NB-1382 | Neuroblastoma | 32.4 | 0.843 | 1.1 | >4 | 0.87 | PD1 | Low |
| OS-1 | Osteosarcoma | 23.8 | 0.036 | 1.2 | >4 | 0.87 | PD1 | Low |
| OS-2 | Osteosarcoma | 25.7 | <0.001 | 2 | >4 | 0.46 | PD2 | Low |
| OS-17 | Osteosarcoma | – | – | – | – | – | PD1 | Low |
| OS-9 | Osteosarcoma | – | – | – | – | – | PD1 | Low |
Tumor Volume T/C value: Relative tumor volumes (RTV) for control (C) and treatment (T) mice were calculated at day 21 or when all mice in the control and treated groups still had measurable tumor volumes (if less than 21 days). The T/C value is the mean RTV for the treatment group divided by the mean RTV for the control group. High activity = T/C ≤ 0.15; Intermediate activity = T/C ≤ 0.45 but > 0.15; and Low activity = T/C > 0.45.
EFS T/C value is defined by the ratio of the median time to event of the treatment group and the median time to event of the respective control group. High activity requires: a) an EFS T/C > 2; b) a significant difference in EFS distributions, and c) a net reduction in median tumor volume for animals in the treated group at the end of treatment as compared to at treatment initiation. Intermediate activity demonstrates criteria a) and b) above, but not having a net reduction in median tumor volume for treated animals at the end of the study. Low activity demonstrates EFS T/C < 2.
Objective response measures are described in detail in the Supplemental Response Definitions. PD1 = progressive disease with EFS T/C ≤ 1.5, and PD2 = progressive disease with EFS T/C > 1.5. Bold font, P-value <0.05.