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LONDON (Alliance News) - N4 Pharma PLC on Tuesday said early in-vivo tests of its Nuvec delivery system did not match positive results from in-vitro tests, causing shares to slump.
Shares in N4 Pharma were down 43% at 4.54 pence in morning trade.
Nuvec is a delivery system for vaccines and cancer treatments and could make viral vaccines more effective. N4 Pharma is collaborating with the University of Adelaide, in Australia, to see if Nuvec can increase the efficacy of the university's vaccine.
Work on this collaboration began in February and testing has been conducted by the university. In-vitro testing, which takes place outside of a living organism, showed a positive response. However, during in-vivo tests - tests in living organisms - this positive response could not be replicated.
Further experiments are planned and the next phase of research can continue once the in-vivo and in-vitro test results are consistent.
Moreover, N4 Pharma has also had difficulties with in-vivo testing in its own studies using a standard test. As with the university's study, "there was an inconsistency in efficacy between the in-vitro data and the findings of the in-vivo studies."
Repeat tests have been recommended and the company is looking to find out what has caused the variation between in-vitro and in-vivo testing. The company's "immediate focus" is now on developing a series of experiments that can find the reason behind these variations.
N4 Pharma Chief Executive Nigel Theobald said: "As we begin working with new antigens, it is important to investigate the required optimisation work to make sure that the dose, vaccine regime and concentration of Nuvec is in the correct proportions to allow good in-vivo transfection. Each new antigen we work with will require this before we begin in-vivo studies. We need to ensure we can replicate the in-vitro successes and efficacy in-vivo before moving to the next stage of each study. Such findings are not unusual for any research and development work and it is important to get it right before more expensive in-vivo studies are commissioned.
Theobald added: "The board and its technical team are defining the experiments to achieve these objectives as we fully digest the data to date and expect to be in a position to set these out in the coming weeks."
