Two preclinical studies which evaluated AVI-7100 against a fully virulent pandemic H1N1 (swine flu) virus had promising results, says AVI Biopharma Inc. Data from the studies revealed statistically significant reductions in average viral titer vs. a saline control (placebo) and a Tamiflu control.

(Pre-clinical studies means studies with animals, not humans)

J. David Boyle II, interim President and CEO of AVI BioPharma, said:

These H1N1 results build on the significant success we’ve had applying our RNA-based technologies and advanced proprietary chemistries, such as PMOplus(TM), to anti-infective therapeutic candidates. Based on these results, TMT continues to support AVI-7100, funding an accelerated IND enabling program and Phase 1 study, as well as expanded preclinical evaluation that explores AVI-7100’s potential as a broad spectrum influenza therapeutic. We look forward to continuing to work closely with TMT to support our national preparedness against biological threats.

AVI Biopharma says that the studies of AVI-7100, which used AVI’s proprietary PMOplus(TM) chemistry, were supported by the Transformational Medical Technologies program (TMT) of the U.S. Department of Defense to identify RNA-based drug candidates against pandemic H1N1 virus. The studies were undertaken as part of a rapid response exercise demonstrating TMT’s ability, in partnership with AVI, to rapidly respond to a real-world emerging viral threat.

AVI-7100, a saline solution and Tamiflu controls were evaluated against a fully virulent strain of pandemic H1N1 virus. AVI-7100 demonstrated “significant reductions in the average viral titer in the upper respiratory region”. In other words, AVI-7000 worked better than the saline solution (placebo) and Tamiflu against the swine flu H1N1 virus.

An analysis of these two studies revealed:

  • AVI-7100 administered intraperitoneally at 10 mg/kg resulted in statistically significant reductions in the combined daily average viral titer through peak viral load (days 1-3) versus saline control (p=0.0012) and Tamiflu control (p=0.0103) by up to 3.9 log.
  • Maximum reductions in the cumulative average viral titer of 5.1 log versus saline control and 4.52 log versus Tamiflu control were observed through day 5, but statistical analysis at this time point was not possible due to limited animal numbers.

Seven days after infection, microscopic examinations of the ferrets’ lungs were done to assess the extent of regional tissue damage.

Pathology scores in both studies revealed only mild damage in the AVI-7100 treated ferrets, while damage was severe in both Tamiflu and saline controls.

The trial researchers revealed that gross examination of the lung and spleens of the ferrets that had been treated with AVI-7100 appeared normal, while there was clear damage in these tissues in the saline and Tamiflu controls.

The total number of infiltrating macrophages in the bronchiolar space was much lower in the AVI-7100 treated ferrets, when compared to the saline or the Tamiflu controls, the study reported.

  • AVI-7100 is an experimental drug.
  • It is aimed at treating patients infected with H1N1 (swine) flu virus
  • Animal experiments showed this experimental drug reduced the total number of viruses in the upper respiratory regions, much more in other standards of care, including Tamiflu.

Influenza-infected ferrets are the closest animals to influenza-infected humans regarding symptoms and the development of the disease.

Source: AVI Biopharma Inc.

Written by Christian Nordqvist