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Fighting Cancer with HIV
Posted on Jul 02, 2013 by Ailee Slater (G+)
What does two pounds look like? Two pounds is a large chocolate cake. Two pounds is a 10-week-old kitten. Two pounds is eight sticks of butter. Two pounds is a substantial amount, so it's no surprise that the international medical community takes note when researchers announce they've found a method to kill two pounds of cancer cells - by injecting the body with HIV.
The first attempt to treat cancer using the human immunodeficiency virus (HIV) occurred in 2010. William Ludwig, a 65-year-old American man suffering from the blood and bone cancer leukemia, had experienced no results from chemotherapy treatment. Desperate, he volunteered himself to cancer researchers at the University of Pennsylvania. These scientists had been investigating the possibility of using HIV to modify a patient's T-cells and instruct them to destroy malignant, cancerous cells.
The results of this first patient-trial were astounding - within a few weeks, over two pounds of cancerous cells had been destroyed, and William Ludwig was completely cancer free. After one year, he was golfing and performing yard work with ease. In 2013, his treatment is still holding strong - the leukemia has not reemerged.
But how can HIV, a virus associated with more than 1 million deaths every year, cure cancer?
The key is a type of white blood cell known as a T-cell. HIV evolved to become extraordinarily proficient at invading a body's T-cells and genetically modifying them. When a person contracts HIV, the virus attacks and commandeers his T-cells. Whereas before these healthy cells were responsible for performing various immune-protection functions, the HIV-infected, now-malignant T-cells will multiply, increasing the strength of the virus and destroying the body's ability to fight off infections.
However, during the past decade, researchers at the University of Pennsylvania realized that HIV's ability to invade and alter T-cells could have a use in curing cancer. The research team came up with a method to collect a patient's T-cells and infuse them with a modified form of HIV - a virus that is powerful, but unable to overrun the body and cause diseases such as AIDS. Instead, this synthetic HIV is engineered to enter healthy T-cells and genetically rewire them to find and destroy any cell with the antigen CD-19; a marker of cancer. Once a patient's T-cells have been exposed to the virus, they are injected back into the patient, where these modified T-cells quickly get to work destroying malignant, cancerous cells.
Although it's odd to imagine doctors introducing HIV into perfectly healthy cells, the as-of-yet limited studies indicate that fighting cancer with HIV has great, great potential. Of the 12 patient trials which have occurred, starting with William Ludwig in 2010, nine patients appear to have fully recovered. All of these patients were in the later stages of cancer, had not responded to traditional treatments, and agreed to undergo an HIV trial as a last resort. Now, in 2013, all nine are healthy and show no signs of remaining cancerous cells, nor of any cancer cell regeneration.
One of these successful trials which has seen a great deal of recent press coverage is the case of Emma Whitehead, aged 7. Diagnosed with leukemia at the age of 5, Emma's illness worsened in the spring of 2012. With little hope of their daughter's survival, Emma's parents decided to go forward with the experimental HIV treatment. As with William Ludwig, the University of Pennsylvania team extracted Emma's T-cells, infused them with the HIV variant and injected them back into her body.
At first, Emma became quite ill - she had a high fever, chills, and difficulty breathing. Especially frightening was Emma's blood pressure; so low that she nearly died. However, the fever eventually broke, her blood pressure stabilized, and the HIV treatment began to work. Now, Emma is cancer-free, whereas a little over one year ago she was not expected to live past the end of the month.
Emma's experience of fever and low blood pressure are common in patients recently injected with the HIV-modified T-cells. When T-cells are activated en masse, the immune system goes into overdrive and releases a flood of cytokines, causing fever, chills and blood pressure changes. In Emma's case, these side effects might have been fatal, if it weren't for the University of Pennsylvania research team leader. Dr. Carl June suggested giving Emma an arthritis drug known to lower cytokine levels - and luckily, his idea worked. Emma's body normalized, and the same drug is now given to other patients experiencing cytokine-related side effects after the HIV treatment.
Besides the immediate physical effects of receiving the HIV/T-cell injection, there are other safety worries regarding this type of treatment. Along with destroying cancerous cells, modified T-cells will also attack the body's healthy B-cells, meaning that a patient who has received HIV therapy will need to undergo frequent intravenous immune therapy to keep the body's immune system fighting off disease as normal. What's more, the HIV treatment could be deadly to some patients - one of the twelve people who underwent the initial HIV trial died 15 minutes after receiving the first injection. Her death was due to severe breathing problems, possibly because cells in the patient's lungs carried the same markers as the cancerous cells, causing the modified T-cells to attack her lungs.
However, there is plenty of evidence that HIV-infused T-cells hold many possibilities for safely treating and even permanently curing cancer. To begin, the HIV treatment works very quickly, making it effective for patients who want to attempt traditional options (such as chemotherapy or bone-marrow transplant) first. Also, the powers of modified T-cells are enormous - each modified T-cell will kill more than 1,000 cancerous cells. HIV injections also appear to be a long term solution. Whereas after chemotherapy cancer will often return, HIV therapy modifies T-cells in such a way that they will continually reproduce: once a patient has received the modified T-cell injection, her body will forever be equipped with a supply of these tiny cancer fighters. Researchers have even indicated that their work might be applicable to a cure for AIDS in the future.
With so many stories of success, HIV treatment for cancer will no doubt receive more attention, more research and more funding in the future. Indeed, the pharmaceutical corporation Novartis recently announced that it will be giving $20 million to the University of Pennsylvania researchers to continue with their work. Treating cancer with HIV - it appears that, in this case, two wrongs may very well make a right.