SGS Clinical Research announces results of FiH studies using novel virus as experimental challenge agent

Strain represents one of the common current circulating strains of influenza of a pandemic origin.

The study, carried out by SGS at their purpose-built human challenge unit, used a GMP-manufactured, non-hemagglutinating, wild-type strain of Influenza A H3N2 in humans at single, ascending titers to determine attack rate (AR), viral area under curve (vAUC) and symptoms following nasal inoculation. Attack rates were defined as two consecutive, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) or quantitative culture (TCID50) positives. The First-in-Human trial demonstrated that the novel challenge agent had high attack rates of up to 100%, no ‘blipping’ at the highest titer and strong symptoms consistent with a non egg-adapted, wild-type influenza virus.

Other highlights of the study, which were presented by Adrian Wildfire, Project Director for Infectious Diseases and the Human Challenge Unit at the recent World Vaccine Congress in Washington DC, included the successful use of the microneutralisation test (MNT) in place of the haemagglutination inhibition assay (HAI) to estimate serosusceptibility prior to challenge. The new assay gave a high degree of predictability regarding infection rates following inoculation. H3N2 (A/Belgium/4217/2015) was shown to cause symptoms consistent with a mild episode of flu in healthy volunteers with no serious adverse events observed during the study or at follow-up.

The SGS challenge agent has lineage from the seasonally epidemic, non-haemagglutinating, H3N2 viruses that arose in the 2010-2011 influenza season and have come to predominate since 2014-2015. This strain represents one of the common current circulating strains of influenza of a pandemic origin. A/Belgium, therefore, offers the potential for testing the H3N2 portion of prospective prophylactic and therapeutic vaccines.

“The outcome of this trial and validation of the virus strain for human challenge trials means future research will not be reliant upon seasonal incidence of influenza, and efficacy of developmental vaccines can be determined directly by measuring multiple clinical endpoints,” commented Mr. Wildfire. “This approach is safer for study participants, and informed go/no go decisions can be made sooner to avoid potentially costly late phase failures.”

Challenge agent manufacture has been undertaken by SGS in strict accordance with Good Manufacturing Practice to ensure that regulatory guidelines in both the US and EU (FDA and EMA) are met