LONDON – Immune Targeting Systems Ltd. (ITS) presented positive data on its universal influenza vaccine, Flunisyn, showing that it induced T-cell responses in 95 percent of subjects in an elderly population, ages 65 to 74, in a Phase IIa trial.

The results pave the way for a challenge study of the vaccine, which is designed to be effective against all strains of influenza A. That would, for example, include influenza A (H7N9), the avian influenza virus that is the source of the current outbreak of human flu infections in China.

The results for Flunisyn in the elderly population are significant not only because of the potential to deal with the threat from influenza viruses jumping the species barrier and causing pandemics, but also because of the limitations of current attenuated viral vaccines against seasonal influenza. In February, the Centers for Disease Control and Prevention reported that the current seasonal flu vaccine was only effective in 9 percent of the older-than-65 population.

"The immune response is compromised in older people, yet we've demonstrated that by using Flunisyn in an elderly population, we can induce a robust T-cell response," Benjamin Chen, CEO of London-based ITS, told BioWorld Today. A response was seen against all six of the synthetic peptide antigens that are included in the vaccine. There was a good safety profile and the cell-mediated immune response to Flunisyn did not inhibit the antibody response to a conventional influenza vaccine in subjects who received both.

On the basis of those results, Chen now expects a Phase II challenge test in healthy volunteers to begin in June. While two previous Phase I studies in healthy volunteers demonstrated that Flunisyn generated T-cell responses against multiple subtypes of influenza A, this will be the first opportunity to test whether that translates through to providing protection against the virus. "With the challenge trial, we will be able to demonstrate for the first time that [Flunisyn] provides protection against infection and that there is a reduction in viral shedding," Chen said.

Assuming a successful outcome, the next stage will be a Phase II field trial. However, Chen said London-based ITS will not go ahead with that until it has found a pharma partner. The company also is looking for nondilutive funding from health agencies, nongovernmental organizations and medical research charities, to support the research.

ITS claims to have overcome all the shortcomings of conventional live attenuated flu vaccines, including the need to prepare fresh vaccines for every flu season, the limited coverage, long manufacturing cycles and short shelf life. As a result, Flunisyn matches the wish list of the FDA, the European Medicines Agency and the World Health Organization for a vaccine that is effective against multiple strains of both seasonal and pandemic flu, provides coverage for immune-compromised groups, does not need to be reformulated for each flu season, can be manufactured in a low-cost, timely way and is stable enough to be stockpiled.

Rather than being produced in hen's eggs or in a cell line, the six antigens in Flunisyn are manufactured synthetically. They are then conjugated to fluorocarbon molecules, resulting in the formation of nanoparticles that are small enough to enter dendritic cells. As the Phase IIa data in an elderly population show, that enables Flunisyn to generate a T-cell immune response, without the need for an adjuvant.

Chen said the Phase IIa data, presented on Tuesday at the World Vaccine Congress in Washington, will assist in the search for a pharma partner, and also oil the wheels of a Series B funding round on which ITS currently is embarked. Chen did not want to say how much he aims to raise in the round. "We have committed investors, and we do have support from them, and we are in late-stage discussions with new investors," he said.

ITS' bioinformatics platform for identifying highly conserved antigens in the internal regions of a virus particle is applicable to the development of vaccines against other viral infections, and the company also announced it has won a £2 million (US$3.1 million) grant to take one program forward. The money from the UK's Biomedical Catalyst Fund will support an 18-month project to advance a vaccine that protects against all subtypes of hepatitis B, for treating chronic infections, to the point where it is ready for clinical development.

In addition, ITS received a second Biomedical Catalyst grant for proof-of-concept work in applying its technology to the formulation of an oncology vaccine.

ITS was founded in 2004 as a spinout from the London School of Pharmacy at the University of London. It raised raised £13.7 million in the first tranche of its Series A round in July 2007 from Novartis Venture Fund, Truffle Capital and HealthCap, taking in a £8.65 million extension to the round in 2010.