Inovio Pharmaceuticals (NYSE MKT: INO) reported Monday that preliminary results from a phase I trial of its H1N1 universal flu vaccine in elderly patients showed a doubling of the response rate of subjects generating infection-preventing antibodies.
The company's H1N1 universal SynCon vaccine, followed by a dose of a seasonal flu vaccine, generated protective immune responses in 40 per cent of trial subjects, compared with a 20 per cent response rate in elderly patients who received the seasonal flu vaccine alone.
Inovio said the interim data is a significant step in developing a more effective flu vaccine for the "most vulnerable" segment of the population, as it noted that people over the age of 65 represent about 90 per cent of annual flu deaths in the U.S.
This is because immune systems of the elderly are weaker, with protective immune responses to seasonal vaccines often seen in just 10 to 20 per cent of this population. Inovio said that this compares to at least 65 per cent of the vaccine recipients in younger adults.
The phase I study is therefore testing the ability of Inovio's SynCon vaccine alone, as well as in combination with the 2012 seasonal flu vaccine, to generate protective levels of antigen-specific antibodies in a greater proportion of the elderly population.
The trial is also seeking to determine the potential for more universal protection against both matched and unmatched seasonal flu strains, Inovio said.
"Today's results provide evidence of the power of our DNA vaccine approach to generate protective antibodies in this vulnerable age group," said president and CEO, Dr. J. Joseph Kim.
"They also show how our vaccines can increase the potency and coverage of existing therapies."
During the trial, 50 healthy elderly patients were divided into three groups, to test the tolerability, safety and immune responses of the different vaccination regimens.
The interim results reported Monday are from the last two arms of the study, being the group of 20 patients receiving the SynCon vaccine followed by a seasonal flu shot 16 weeks later, and a group of 10 subjects getting placebo followed by the seasonal flu shot.
The study is ongoing at the University of Manitoba, in Winnipeg, Canada.
"With limited evidence of other innovations enhancing protection against influenza, this technology could potentially lead to a breakthrough vaccine," said a principal investigator of the study, Dr. Gary P. Kobinger, a professor at the University of Manitoba.
In addition to improving the immune response rate against the matched seasonal strain in the older population, all patient serum samples will also be analyzed against other "important H1N1 strains", Inovio said, to assess the prime-boost regimen's ability to generate universal cross-strain protection. Results of this will be reported next year.
Inovio's SynCon vaccines are designed to provide two capabilities not achievable with conventional vaccines: stimulation of T-cell immune responses to provide therapeutic capabilities, and universal cross-strain protection and treatment against known as well as newly emergent unmatched strains of pathogens. The company has clinical programs for cervical dysplasia, leukemia, the hep C virus, the flu and HIV.
During the third quarter, the company reported that its SynCon vaccine against cervical cancer, known as VGX-3100, achieved an "industry first" when T-cell immune responses induced by this vaccine were shown to generate a strong killing effect against cells changed by HPV into precancerous cervical dysplasias.
In other news Monday, Inovio also said that enrollment for a phase II trial testing a DNA vaccine for hepatitis C is now complete, with preliminary results due in the first quarter of next year.