UK-based Retroscreen Virology Limited has extended its model for challenge studies with human influenza and other respiratory viruses from quarantined ‘Flu Camps’ in hotels or new student accommodation to a Phase I unit, where the company has just completed a volunteer trial to characterise a new influenza A challenge virus.

A contract virology research company spun-out from Queen Mary, University of London, Retroscreen conducts around five clinical trials involving several hundred participants each year. Building on the concept of experimental challenge initiated at the Common Cold unit on Salisbury Plain in 1948, the Flu Camp studies have been a particular speciality, with volunteers recruited through word of mouth or advertising on the London Underground.

Using a Phase I unit allows Retroscreen to move into an earlier stage of development where less information is available on the treatment under investigation, noted Dr Robert Lambkin-Williams, managing director of Retroscreen Virology. The influenza A challenge study involved taking “a lot of blood samples” from volunteers, he commented.

The new set-up “works very, very well”, Lambkin-Williams said. In future, Retroscreen intends to continue its relationship with the (as yet unspecified) Phase I unit while retaining the Flu Camp model for situations in which a drug would normally be taken at home.

The latest trial looked at the infectious titre of the A/Wisconsin/67/2005 (H3N2) virus required to provoke mild illness in volunteers. The aim is that the virus will later be used in the evaluation of influenza vaccines and antivirals.

Retroscreen also obtained a variety of samples from the infected volunteers. These will contribute to the development of new diagnostic techniques and laboratory tests that “may be invaluable in the event of a Pandemic influenza outbreak”, it said.

Preliminary results of the influenza A challenge study are expected to be announced at a symposium on the 1918 ‘Spanish’ influenza pandemic, to be held by Retroscreen in London on 10 November.

The experimental challenge model removes the need to wait for natural outbreaks of influenza or other respiratory viruses of interest to Retroscreen, such as rhinovirus or respiratory syncytial virus. As such, Lambkin-Williams claims it can shave two to three years off the drug development cycle compared with traditional field-based approaches.

Retroscreen received a boost in August 2006 when IP Group, an intellectual property commercialisation company that specialises in technology sourced from universities, invested £1 million to take a 25% stake in the spin-out. Retroscreen now has a staff of around 60 and generated turnover of roughly £5 million in 2006/07.