Table 2.
Pros and cons of suicide gene technologies.
| Category | Example | Clinically validated | Pros | Cons |
|---|---|---|---|---|
| Metabolic | HSV-TK | ✓ (safe) | Gradual onset | Immunogenic in immunocompetent pts; unwanted elimination of modified T-cells with tx use of GCV |
| Eliminates alloreactive cells | ||||
| Dimerization inducing | iCasp9 | ✓ (safe) | Rapid onset | Incomplete elimination, although of ≥90% of cells |
| Eliminates alloreactive cells | ||||
| Non Immunogenic | ||||
| Use non-therapeutic agent | ||||
| Therapeutic mAb mediated | Surface molecule (e.g. CD20) | ✘ (not validated) | Rapid onset | On-target toxicity from mAb |
| Non immunogenic | ||||
| No additional selectable marker required |
Legend: HSV-TK, herpes simplex virus thymidine kinase; GCV, ganciclovir; iCasp9, inducible Caspase9; tx, therapeutic.