Cancer-killing viruses
MediGene is developing cancer-killing viruses (oncolytic viruses) for the treatment of various types of cancer. The basis for this is specifi c herpes simplex viruses, or HSVs, generally known as the cause of cold sores. MediGene uses these viruses, however, in a modifi ed and »disarmed« form in order to make them utilizable as a therapeutic agent in humans. This has been achieved by switching off certain viral genes that normally enable the virus to multiply in specifi c healthy cells, thereby destroying these cells. As a result of this genetic modifi cation, the oHSVs are able to reproduce in tumor cells solely, since only these degenerated cells are able to compensate for the loss of the removed viral genes. Consequently, MediGene’s herpes simplex viruses are able to replicate specifi cally in the tumor cells, destroying them (oncolysis) without harming healthy tissue. This mechanism was verifi ed in comprehensive laboratory experiments. If it also turns out to be effective in the ongoing trials with tumor patients, oncolytic HSVs may act more selectively and effi ciently than conventional cancer therapies. In particular, they could provide a therapeutic option for the treatment of tumors that are inoperable or have developed a resistance to chemotherapy, radiotherapy, or antibody therapy. Possible synergistic effects in combining oncolytic HSV and standard therapies are also possible. Preliminary phase I clinical trials with cancer patients have already yielded positive results.
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Outlook
In January 2009, on the occasion of the ASCO GI meeting, MediGene presented positive results obtained in a phase I/II trial in the indication advanced colorectal cancer metastatic to liver. In the course of its strategic focusing, MediGene is planning to spin off or to sell a license for this program.
| Oncolysis by means of HSV |
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Oncolytic virus is applied to the tumor |
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Tumor cells support virus replication |
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Tumormass is selectively destroyed (>> oncolysis <<) |
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Complete destruction of the tumor. |
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