| Ritlecitinib nitrosamine impurity 5 | NA | Ax-17601 |
| Ritlecitinib impurity 4 | 1792184-37-2 | Ax-17600 |
| Ritlecitinib impurity 3 | NA | Ax-17599 |
| Ritlecitinib nitrosamine impurity 4 | NA | Ax-17598 |
| Ritlecitinib impurity 2 | NA | Ax-17597 |
| Ritlecitinib nitrosamine impurity 3 | NA | Ax-17596 |
| Ritlecitinib nitrosamine impurity 2 | NA | Ax-17595 |
| Ritlecitinib impurity 1 | 1227917-63-6 | Ax-17594 |
| Ritlecitinib nitrosamine impurity 1 | NA | Ax-17593 |
| Ritlecitinib Dimer | 2374827-88-8 | Ax-17592 |