HIV shown to be promising as a treatment for cancer

A couple of months ago, a group of French scientists reported that they found a way to use HIV as a means to treat cancer. They showed some promising results in the lab, indicating that the virus could be a lot more effective than conventional treatments. Now, the first clinical trial has been performed with a similar technique, and it appears as if HIV may indeed be useful in the development of a decent cancer treatment.

Remission
A total of 12 patients suffering from leukaemia were included in the study, that was conducted by the University of Pennsylvania. Among them were two young children that had no other treatment options left. The researchers report that two out of the three patients that had previously received the treatment are in remission, which basically means that the signs and symptoms of their disease are gone. This comes pretty close to a cure, but there is always a chance that the cancer comes back. So far, these patients have managed to stay alive for more than 2 years already, after they had received treatment. Hopefully, the therapy will be equally successful for the patients that have been enrolled in the clinical trial.

Kill
Being in remission means that the cancer cells found in the body are killed. To achieve this goal in the aforementioned patients with leukaemia, the scientists modified cells of the body's immune system. In this specific form of leukaemia, so-called B cells, also part of the immune system, are growing uncontrollably and this forms a treat. Other immune cells, so-called T cells, are supposed to kill these malicious B cells, but they are not well-equipped to do so.

Modification
To get the T cells the 'weapons' they need, the scientists modified them with a 'vector' that infects the cell. This little shell contains genes that are inserted into the genome of the cell, and this mechanism of action is very similar to how a virus normally works. The Pennsylvania scientists used HIV as their vector, because this virus is known to specifically infect T cells and thereby destroy our immune system. However, the vector they used is pretty harmless and only modifies the T cell to make it start producing a certain protein that renders them able to specifically target the B cells that cause the leukaemia.

Therapy
Patients that undergo this new form of treatment have to 'donate' blood, after which the T cells, that normally roam our circulatory system, are reprogrammed in the lab with the newly developed vector. After that, the cells are given back to the patient, ready to go kill malicious B cells. Normally, patients would receive a full bone marrow transplant, which means their original bone marrow, responsible for producing all kinds of immune cells, is destroyed and replaced with new marrow, that does not produce the malicious B cells. However, it is much better to let the body's own immune system do its job and eradicate those cells that do not behave.

Outlook
Because the therapy works on patients that basically had no other options, it seems to be a promising new weapon in the battle against cancer. It is not the first time scientists try to recruit the body's own immune system by means of viral modification, but this study is pretty far up in the development process. Hopefully this study will be followed up by a large-scale clinical trial showing efficacy in a large number of patients. The necessary pharmaceutical tools to bring this to the clinic will be marketed by Novartis, a big pharma company.

An artist impression of HIV.