To keep the future of cancer clinical trials promise thanks to Oncolytic viruses

Chemotherapy has always and still is our first line of Defense, but is not for the faint of heart. Any form of chemotherapy is still routinely prescribed for most types of the disease. The treatment works fast-growing cells, such as those in the fast-growing tumors treatment approach. But during chemotherapy tumors can shrink, grow again and resistant, or to the treatment.

To combat this resistance is chemotherapy the various mechanisms for attack now often used in combination with other treatments, and kill cancer cells have. Doctors must be careful when mixing treatments to ensure that the therapy is non-toxic to tolerate for patients. Aim is to introduce drugs, to extend the synergistic not only life, but can be used to improve the quality of life in treatment with chemotherapy.

Known as Oncolytic Virotherapeutics is an approach that proved to be quite promising. Here are viruses to infect made usable, multiply within and then solve cancer cells; The virus targets tumors without impact on normal tissue.

Different types of Oncolytic so far developed viruses. The adenovirus include, Newcastle-disease virus and smallpox (Vaccinia Virus), the farthest, the advanced Jennerex JX-594 is probably, also in phase II liver cancer test is carried out and is a partnership with French biotechnology company transgene. The herpes simplex virus is also considering as an Oncolytic virus; many engineered versions are in clinical trials for the treatment of patients with cancer, the most advanced of which developed OncoVEX, of BioVex (now part of Amgen), and currently is phase III testing in melanoma and head & neck cancer. Two other varieties in previous studies are Picornaviruses and vesicular stomatitis virus.

Finally we come to what some look at the most promising form of Oncolytic virus: the Reovirus. This virus replicates this feature preferred in cancer cells a common mutation known as a "enabled RAS pathway," while sparing normal cells. This intrinsically tumor selective without the need for genetic manipulation.

Reovirus is a virus with no known associated disease. It replicates in the cytoplasm and therefore does not integrate the cell DNA. Reovirus is everywhere found in nature and was isolated from untreated sewage, River and stagnant waters. Exposure to Reovirus has been testing positive adulthood often in people with half of the children in the age of 12 exposed and up to 100%.

Tumors with an enabled RAS way can the anti virus response by the host cellular protein, PKR gives do not enable. Studies have shown that Reovirus actively replicated in transformed cell lines with an active RAS signaling pathway, eventually killing the host cell and infect and kill liberation of viral progeny more RAS enabled tumor cells, to go. Are infected with the normal cells with Reovirus, the immune system can neutralize the virus. About a third of the human cancer have mutations in the RAS-gen itself, and it is possible that more than two-thirds of cancer cells upstream signal an enabled RAS away due to the mutations in genes or activate downstream of RAS.

While it has been shown in animal studies, that Reovirus is in the location of the treatment of metastatic immune competent mice, it has also been found, that Reovirus used in conjunction with immunosuppressive drugs can extend effective animal survival.

This supports the development of clinical protocols where immune suppressive could be combined drugs with a systemically administered Reovirus for the treatment of cancer. The combination of Reovirus with different chemotherapy regimens in human colorectal cancer cell line showed synergistic cytotoxic activity. In addition to the modulation of the immune response, the use of chemotherapy with Reovirus treatment can improve intratumoral spread of the virus.

Calgary-based Oncolytics Biotech Inc. has a biologic agent, Reolysin, developed from naturally occurring Reovirus. The virus has shown impressive results in clinical trials on their own, but in particular in combination with certain chemotherapy drugs. In preclinical studies in a variety of be investigators, found that when used together, Reovirus and chemotherapy resulted in more efficient and synergistic anti-cancer activity than if each agent was used on its own.

These combinations shows very good results in human studies, in particular in refractory head and neck cancer patients. Cancer patients treated with a combination of Reolysin many head and neck and have so far experienced chemotherapy, dramatic and long-lasting tumor shrinking, without increasing side effects.

It is viruses a crystal clear economic forecast for Oncolytic difficult. However demand for new and effective agents in Oncology remains high, which are us confidence that Reolysin could also embraced when it performs well in the phase III trial. Global oncology-focused pharmaceutical company may interested, partner with Oncolytics Reolysin phase-III head and neck cancer data are available, if not before, and capital markets issue optimism in Reolysin's medical perspective.

As we have seen, there are a number of Oncolytic viruses, which have shown can be used in cancer therapy and demand for effective agents is strong. Future studies are still clear view on that type, if available, these viruses reliably and economically viable addition to chemotherapy offer the most effective way for oncologists and their patients.

Source: Oncolytics Biotech