Table 1.
Summary of current methods being researched in Clostridium-based cancer therapies.
| Method | Premise | Target/drugs | Clostridium species being used | Reference |
|---|---|---|---|---|
| Clostridium directed enzyme prodrug therapy (CDEPT) | Clostridium is genetically engineered to express an enzyme which cleaves a prodrug into its cytotoxic form. | CD/F-FU |
C. sporogenes
C. beijerinckii C. acetobutylicum |
[39] [49] [41] |
| NTR/CB1954 |
C. beijerinckii
C. sporogenes |
[37] [40] |
||
| NTR/PR-104 | ||||
|
| ||||
| Administration of cytokines/cytotoxic agents | Clostridium is used to deliver agents (cytokines) to either act directly cytotoxic to cells or enhance immune system response to tumour cells. | murine TNFα | C. acetobutylicum | [41, 50, 51] |
| IL-2 | C. acetobutylicum | [42] | ||
|
| ||||
| Clostridium directed antibody therapy (CDAT) | Clostridium is modified to produce highly specific antibodies against tumour antigens. | VHH against HIFα | C. novyi-NT | [45] |
|
| ||||
| Combined bacteriolytic therapy (COBALT) | Clostridium which demonstrate direct antitumour effects are administered in conjunction with other known cancer therapies to increase oncolysis. | Clostridium/ mitomycin C and cytotaxin Clostridium/vinorelbine or docetaxel |
C. novyi-NT
C. novyi-NT |
[47] [52] |
|
| ||||
| Release of liposomal encapsulated drugs | Species of Clostridium which secrete lipid-degrading enzymes are used for the targeted release of liposome-encapsulated drugs at the tumour site. | Clostridium/Doxil | C. novyi-NT | [48] |