With the help of antiretroviral (ART) therapy treatments, an HIV diagnosis is no longer a death sentence. In fact, patients who are tested for the disease and begin treatment at an early stage now have a similar life expectancy to those without the infection. However, while HIV is now referred to as a chronic, manageable illness, it still has no cure.
Researchers are working hard to change this and a safety study published today in Molecular Therapy represents an important step forward in the hunt for an effective treatment. Scientists from the University of North Carolina successfully demonstrated the safety of a cell therapy involving the ex vivo expansion of T cells and their infusion in HIV positive patients in combination with antiretroviral drugs in a phase I clinical trial. We talked to co-senior study author David Margolis to find out more.
Morressier: Briefly explain the findings of your study and their significance
David Margolis: The focus of this safety study was to find a way to re-educate the body’s immune system to better fight HIV infections that, despite ART treatment, remain in the body within a latent reservoir that is hidden from the immune system. This study is the required fist step to show that HXTC cells can be administered safely and to provide some preliminary evidence about how long the cells might last in patients or if they might work.
Morressier: What was the method of your study?
Margolis: Adoptive T-cell -therapy has already successfully been used against viral antigens in other populations, mostly patients with cancer. Because of this, the safety data needed for this study was thought to be relatively small, hence our small sample size. The protocol of our study was simply to administer an infusion of cells into the patients and take note of the safety parameters with clinical observations and routine laboratory observations. The procedure itself involved collecting T cells from a patient, growing them in the laboratory to increase their numbers, and then giving them back to the patient to help the immune system fight disease. We administered two infusions of HXTCs over a 2 week period to six HIV-infected participants whose viral load had been reduced to an undetectable level by ART.
Morressier: How confident are you that we are close to finding a cure for HIV?
Margolis: This is a question that I am asked all the time. One can’t be completely confident that a cure for HIV can ever be found. We have to have the patience and dedication to work in a logical way, step by step, to try and find a cure for HIV. I’m hopeful this approach will result in a cure for AIDs at some point in the not-distant future.
Morressier: If further research proves your technique of re-educating immune cells and re-infusing them in HIV patients to be successful, could this be a valid treatment for a significant number of HIV patients or would its cost and/or accessibility be prohibitive?
Margolis: We think this specific kind of therapy as its done at the moment would certainly be too costly and complicated to apply to the millions of people across the world who would need such a therapy. On the one hand, this kind of therapy could teach us how to clear latently infected cells, so would provide a proof of concept and give us some form of direction in our search for a cure, however the other thing to remember is that technology is always advancing and things we thought of as impossible ten or even five years ago are now possible. So I wouldn’t rule out the possibility that cellular therapies could be used on a broader basis across the world in the years to come, just not right now.
Morressier: What are the limitations of your study?
Margolis: They are relatively few as this was a safety study. The major limitation is that the sample size was quite small and additional safety risks could arise – we would need to treat many more people for a significantly longer period of time to establish this. However, we feel this evidence means we are safe to move forward to the next step, which again would be a study that looks at the possibility that these kinds of cells can have an anti reservoir effect when given in combination with a latency reversing agent.
Image courtesy of Hans Reniers