In 2005 Dr. Kenichiro Hasumi, a Japanese physician and researcher who has dedicated 40 years of his life to cancer immunotherapy research stumbled upon the right protocol, one that is scientifically sound. He found that dendritic cells when injected into tumours can locate the cancer cells for killer T-cells to neutralise. He has named the protocol Human Initiated Therapeutic Vaccine Therapy.
Immunology, which harnesses our immune system’s innate and adaptive ability to combat diseases, adds another dimension to the mainstays of cancer treatment, i.e. surgery, radiotherapy and chemotherapy.
Human Initiated Therapeutic Vaccine (HITV) Therapy
HITV therapy is a new weapon to use in the long drawn battle with cancer. It is an autologous (patient derived) active cell-based immunotherapy for patients with metastatic or late-stage cancer that has been found to be highly effective when used in combination with radiotherapy. The treatment is able to annihilate microscopic and tiny nests of cancer cells thereby preventing any future cancer occurrence.
The efficacy of HITV Therapy is greater in the following patient’s conditions:
· Solid lumps – applicable for any type of solid cancers at any stage as long as they are accessible by needle. However HITV Therapy is not suitable for leukaemia and brain tumours.
· Tumours localised in treatable sites – as intra-tumoural injection of dendritic cells is the hallmark of HITV, it is important that the tumour is located in parts of the body that are accessible by needle.
· Tumour size of less than 3 cm in diameter – this limitation is due to the standard beam diameter of Tomotherapy which is 3 cm. Dendritic cell vaccine is also ineffective when injected into the necrotic (dead tissue) centre of large tumours.
· Less than five metastatic tumour lesions – again, the limitation is due to the adverse reactions to radiotherapy that may occur when multiple sites have to be treated in one sitting. However, Dr. Hasumi has experience in treating up to 15 lesions in one go.
· No pleural or peritoneal ascitic effusion – pleural and peritoneal ascitic effusion are typical signs of extensive cancer dissemination and the chances of success in such cases is greatly diminished.
How does HITV Therapy work?
The protocol involves the harvesting of peripheral blood mononuclear cells from the patient and culturing them in the laboratory to differentiate into immature dendritic cells and then introducing them back into the patient’s body through injections into the tumour(s). In round 1, the cultured immature dendritic cells that have been injected into the tumour act as the reconnaissance soldiers that will hunt out the cancer cells and gather information for the infantry. Once the information is passed on to the infantry, the soldiers or killer T-cells will launch specific attacks to destroy the enemies (cancer cells).
Round 2 involves a combination of Tomotherapy, an advanced form of intensity modulated radiation therapy (IMRT) and another intra-tumoural injection of immature autologous dendritic cells. Tomotherapy precisely targets all the tumours in one sweep to kill off the cancer cells while reducing radiation exposure to the surrounding normal tissues. The second round of HITV Therapy does the final cleansing.
The success of the treatment
Dr. Hasumi has treated over 350 patients with metastatic cancer since 2008 at his clinic in Tokyo (ICVS Tokyo Clinic) and he has a success rate of 70 per cent.
Direct injection of dendritic cells into the tumour allows for adequate numbers of such cells to reach the tumour site where they generate therapeutic cancer vaccine, causing the regression of the tumour and at the same time enhancing immune response dramatically. Through intra-tumoural injection, dendritic cells also have the benefit of an ideal in vivo (occurring in a living organism) environment in the patient’s body so there is less chance of antigenic difference.
HITV Therapy used in combination with radiotherapy achieves two goals – that of damaging the cancer cells to kill them and wiping out the regulatory T-cells (T-cells that suppress the activation of other T-cells like the killer T-cells) within the tumours. The second round of HITV treatment will wipe out the newly mutated cancer cells that have moved outside the treated sites enroute to new sites which will later show up as new tumour lesions.
Treatment found to be safe
Patients who have undergone HITV treatment have not shown any adverse effects at all. As the dendritic cells are harvested from the patient’s own body for culturing in the laboratory, then introducing them back into the patient’s body, there is no harmful reaction. There are few side effects; at worst, some patients experienced mild fever or flu-like symptoms.
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