Sontra Announces Promising Initial Human Clinical Results from Transdermal Vaccination Study

FRANKLIN, Mass. -- Sontra Medical Corporation announced promising initial human clinical results from a twenty patient study conducted by Daniel H. Libraty, MD at the University of Massachusetts Medical School that evaluated the immune response induced by using the SonoPrep skin permeation device to facilitate the transdermal delivery of the antigenic proteins, tetanus toxoid and candida albicans (yeast).

In this study, 10 patients in the treatment group first received a fast (10-30 seconds) SonoPrep skin pretreatment on their forearm creating an imperceptible window for drug delivery through the skin. Then the antigenic proteins, tetanus toxoid and candida albicans were applied topically to the treated skin sites. A 10-patient control group received the standard intradermal injection of the same antigenic proteins. The immune responses induced by these antigenic proteins were evaluated by measuring the extent and duration of the skin reaction, known at the delayed-type hypersensitivity response (DTH). A DTH skin immune response was induced in 90 percent of the SonoPrep treated patients and the duration of the DTH skin reaction was similar in the treatment group versus the control group.

"I think this is an innovative technology with interesting potential in vaccinology and modulation of immune responses to infectious pathogens" stated Libraty, an assistant professor of medicine at the Center for Infectious Disease and Vaccine Research at the University of Massachusetts Medical School in Worcester.

Following the completion of this first study, Sontra had initially planned to complete a second human study at the University of Massachusetts Medical School using SonoPrep to facilitate the transdermal delivery of an influenza vaccine. Due to the current shortage of flu vaccines and concern by public health officials, Sontra has decided to donate its existing supply of flu vaccine to the medical school's clinical partner, UMass Memorial Health Care and will instead commence a second vaccine study later this fall with a hepatitis A vaccine.

"We are very pleased with the promising results from our first transdermal vaccination study" stated Shikha Barman, PhD, director of transdermal drug development at Sontra. "We believe that our SonoPrep skin permeation technology can facilitate transdermal vaccination and improve clinical outcomes. Because SonoPrep controls the actual permeability of the skin surface, antigens can be precisely delivered and a powerful immune response can be induced by activating the Langerhan cells in the epidermis. To date the majority of vaccines are delivered by needle injection. Not only does SonoPrep have the potential to improve the efficacy of vaccines, transdermal vaccines also eliminate the risk of inadvertent needle generated disease transmission and patients always prefer pain-free therapy."

Source: Sontra Medical Corporation