Inovio Pharmaceuticals (NYSE MKT:INO) (AMEX:INO) said this morning it has taken a "major stride" toward its universal flu vaccine, sending shares higher Thursday.
Shares were up more than 5.5 per cent in early morning trade, at 57 cents as of 10:00am ET. Its stock exceeded the 50-day average volume earlier Thursday.
The company said an interim analysis of its SynCon universal H1N1 flu vaccine from a phase I clinical trial showed that the vaccine generated protective HAI titers against some of the "most prevalent" strains of H1N1 flu from the past 100 years.
Because Inovio's SynCon approach incorporates sequence information from multiple divergent strains, the vaccine is not matched to any of the historical flu strains.
Protection against multiple unmatched strains represents a major step toward the company's ultimate goal of developing its universal flu vaccine - designed to protect against known and newly emerging strains of the flu, Inovio said.
The flu virus is ever-mutating, and it is a challenge each year for health officials to match the seasonal vaccine to the current circualting strain.
“With respect to influenza, our ultimate objective is to develop a universal vaccine capable of providing years of true preemptive protection across subtypes and strains,” said president and CEO, Dr. J. Joseph Kim.
“This is a challenging goal but this proof-of-principle H1N1 data demonstrates the potential of our SynCon approach to generate cross-protective HAI titers against multiple unmatched influenza strains.
The current open label phase I study tested two synthetic H1N1 hemagglutinin (HA) plasmids designed to broadly protect against unmatched flu strains within different branches of the H1N1 subtype.
These plasmids were given to healthy adults with Inovio’s Cellectra intradermal electroporation device up to three times.
The delivered vaccine was well tolerated, the company said, and reported adverse events and injection site reactions were mild to moderate, requiring no treatment.
"These results are an important addition to our previously reported H5N1 phase I data and a validating achievement on our ongoing effort to develop a safe vaccine that provides immunity against the ever-changing influenza virus," added Dr. Kim.
During the phase I study, researchers exposed blood samples from the vaccinated subjects to each of the nine key H1N1 viruses in circulation over the last 100 years, eight of which were used to formulate the seasonal vaccines of the last 25 years.
One of the viruses was the H1N1 strain that caused the 1918 Spanish flu, which killed more than 40 million people, the vaccine developer noted.
An HAI, or hemagglutination inhibition, titer of 1:20 is generally regarded as a positive vaccine response, while 1:40 is the level recognized as a protective immune response against influenza in humans.
The company said the results showed a "significant percentage" of subjects immunized with Inovio’s SynCon vaccine had an HAI titer of 1:40 or higher against each of the nine H1N1 strains tested, ranging from a 30 per cent response rate to a 100 per cent response rate.
The benchmark for the current licensed seasonal flu vaccines, which are based on matching the vaccine HA sequence to that of the circulating strain, is to have greater than 65 per cent of the vaccines generate an HAI titer of 1:40 or higher against the matched vaccine strain, Inovio said.
The phase I study is ongoing, with additional results from a higher dose group expected in 2013.
Inovio is also conducting optimization studies in animal models to further strengthen its H1N1 vaccine’s potency against all strains, especially the current circulating strain, as well as to reduce the number of injections needed to generate protective responses against a number of different strains.
The company's SynCon vaccines are designed to provide universal cross-strain protection against pathogens like the flu together with its electroporation delivery device. It has clinical programs in place for its synthetic vaccines for cervical dysplasia, leukemia, hepatitis C, and HIV, among other diseases.
Inovio said that when compared to the seasonal trivalent flu vaccine control group, those given the company's vaccine generated a higher or similar percentage of protective responses against all of the strains with exception to the current circulating one - to which the seasonal vaccine is matched.
The drug developer's development focus is on the elderly market, which it believes has the greatest unmet need. The goal is to develop a more effective flu vaccine for those over 65 years of age, who currently account for about 90 per cent of seasonal flu-related deaths, Inovio said.
The results today follow the company's recent announcement that its SynCon H5N1 plasmid construct generated high levels of antigen-specific antibodies and protective responses against six different H5N1 strains.
Its plans with this product is to access the pandemic stockpiling market, which is dominated by government buyers, the company noted.
Inovio also recently launched a third flu study, called Fluprime, using its H1N1 construct alone and in combination with the 2012 seasonal influenza vaccine. Immunogenicity data is expected next year.