Inovio Pharmaceuticals (AMEX:INO) said Tuesday that it has achieved strong T cell immune responses in a phase one study of its Pennvax-B vaccine for the treatment of an HIV subtype prevalent in North America and Europe.
results from the study, which tested HIV-positive patients, were
presented by Inovio's chief operating officer, Dr. Niranjan Y. Sardesai,
at the Vaccine World Summit 2012 in Hyderabad, India.
particularly excited by the positive interim results of the HIV-001
study in HIV-positive subjects," said president and CEO, Dr. J. Joseph
"This data is a first for DNA vaccines by yielding robust T
cell immune responses in people chronically infected with HIV. Even
though the HIV viral load of these volunteers was suppressed and brought
under control by antiretroviral drugs, their immune systems are not
normal and would typically have difficulty generating strong T cell
responses to any immune stimulating approach.
positive data from two earlier trials, Inovio’s results demonstrate the
potency of our synthetic vaccine technology platform and raises the
potential for the development of therapeutic vaccines against HIV and
other chronic infections."
The HIV-001 open label, phase one
study enrolled 12 adult HIV-positive volunteers to assess safety and
levels of immune responses generated by Inovio’s vaccine delivered with
the company's Cellectra electroporation device.
consists of SynCon immunogens targeting HIV gag, pol, and env proteins
from HIV subtype B, which is commonly found in North America and Europe,
Overall, the company said significant
vaccine-specific T-cell responses were observed in 75 percent of
subjects against at least one of the three vaccine antigens (gag. pol,
or env) following vaccination.
Fifty percent of the subjects had
strong vaccine-induced antigen-specific responses above the
pre-vaccination levels to at least two of the antigens. Importantly, the
responses were predominantly antigen-specific CD8+ T-cells, Inovio
said, which are considered to be "paramount in clearing chronic viral
infections and an important measurement of the performance of a
"These results are in stark contrast to
previously reported studies with other DNA vaccines delivered without
electroporation that yielded poor overall T cell immune responses," the
company added in a statement.
In the study, 12 eligible subjects
were administered a four dose series of the vaccine containing 3
milligrams of DNA/dose via intramuscular electroporation. Inovio said
there were no significant adverse events reported, with the vaccine
found to be generally well-tolerated.
T-cell responses were
measured using a validated ELISpot assay at the University of
Pennsylvania Immunology Core Facility. The clinical study was sponsored
by Inovio Pharmaceuticals and conducted at the University of Pennsylvania Medical Center.
added: “Together with our HIV prophylactic vaccine programs in
collaboration with our partners at DAIDS and HVTN, this HIV therapy
trial highlights our commitment to addressing one of the foremost global
health issues of our time.”
According to the Joint United
Nations Programme on HIV/AIDS, nearly 30 million people have died from
HIV-related causes and roughly 34 million are living with HIV.
a HAART regimen has dramatically transformed the treatment of the
disease in developed countries, effective HIV vaccines can be used to
stop the spread of disease and perhaps reduce the need for
antiretroviral treatments, which generally have harsh side effects and
which in many cases lose their efficacy over time.
In a previous
trial, Inovio reported strong T-cell immune responses to the Pennvax-B
vaccine in health adults in a preventative setting. In that trial, over
89 percent of the vaccinated subjects mounted an antigen-specific T cell
response against at least one of the vaccine antigens.
SynCon vaccines are designed to provide universal cross-strain
protection against known as well as newly emergent unmatched strains of
pathogens such as influenza.
These synthetic vaccines, in
combination with the company's proprietary electroporation delivery,
have been shown in humans to generate strong immune responses with a
favorable safety profile.
Inovio's clinical programs include
phase two studies for cervical dysplasia, leukemia and hepatitis C virus
and phase one studies for influenza and HIV.