N4's 'nuvec' has no systemic toxicity, study shows

Specialist pharmaceutical company N4 Pharma announced the latest research results for its ‘nuvec’ nanoparticles, which it was developing as a delivery system for DNA and mRNA vaccines and therapeutics, on Friday.

The AIM-traded firm said the objective of the study - funded via a biomedical Catalyst grant - was to assess the systemic tolerability of the nuvec silica nanoparticles when administered as a single dose via subcutaneous injection to rats, a standard non-clinical species for such studies.

Animals were dosed once with 50, 150, 400 or 900 mg/kg nanoparticles, and then observed for 14 days.

Clinical observations, body weights and food consumption were recorded, blood plasma samples were analysed for clinical pathology and selected common target organs were examined microscopically, the board explained.

It said the nanoparticles did not cause any systemic toxicity, and all organs examined microscopically were normal - including at the highest dose - which was likely to be “many times” in excess of the concentrations that might be administered to humans, it added.

While there was “some mild to moderate inflammation” observed at the injection sites, at all doses, these were said to be nonspecific, and generally indicative of local inflammation.

According to the board certified pathologist used in the study, the inflammation was similar to that which would be expected following implantation of a medical device or as a result of injecting a vaccine, and would “almost certainly” resolve over time.

“A single subcutaneous administration of the nuvec nanoparticles to rats did not cause any toxicological effects considered likely to be of long term concern,” the board confirmed.

ApconiX - the company's partner in the studies - approved that was an “accurate reflection” of the results observed.

Following the results, further in vivo studies to demonstrate the transfection capability of nuvec particles was planned.

“We continue to make good progress demonstrating the capability of our nuvec vaccine delivery system,” said N4 CEO Nigel Theobald.

“We have already demonstrated its transfection capability compared to standard industry in vitro techniques - lipofectamine - and it is important we undertake studies to further show we can achieve transfection in an in vivo environment.

“Whilst there remain several important steps before we can demonstrate the suitability of our nuvec system to our potential commercial partners, the fact that we can show there is no systemic toxicity is a very important hurdle to overcome.”