Patch-based travel vaccine looks good
after the announcement of Phase II results.
Iomai is developing a patch-based and needle-free vaccine for travellers' diarrhoea, which if approved would move into a travellers' diarrhoea vaccine market worth $750m (€528.9m). The Phase II study showed that vaccinated travellers were 75 per cent less likely to suffer clinically significant diarrhoea and 84 per cent less likely to suffer severe diarrhoea. Described as the "most robust" data ever shown in the prevention of travellers' diarrhoea, if successful, the patch vaccine will be targeted at the 55 million travellers who visit countries where the bacteria that causes travellers' diarrhoea is endemic. "Diarrhoeal diseases are a top priority in global public health and we believe that our approach has the potential to save the lives of many of the world's most vulnerable: infants, and children in the developing world," Iomai chief scientific officer Gregory Glenn said. "We have demonstrated that vaccinated travellers can dramatically cut their risk of diarrhoea by using our needle-free patch. Those who received the Iomai vaccination were much less likely to get sick, and those who were sickened had far milder illnesses that those who received a placebo. These are clinically significant results that suggest that the patch vaccine will address the most significant unmet need for travel medicine: prophylaxis for travellers' diarrhoea." Iomai's vaccine uses an Enterotoxigenic E. coli (ETEC) toxin delivered via a skin patch using the company's novel transcutaneous immunisation (TCI) technology. ETEC causes illness through the toxins it produces, including one known as heat-labile toxin or LT. Iomai's patch enables the safe administration of this potent immunogen into the skin. The toxin is delivered to a group of antigen-presenting cells called Langerhans, located on the skin's outermost layer, which in turn deliver the vaccines and adjuvants to the nearby lymph nodes to produce a sustained immune response. Needle-free benefits of the vaccine are one advantage, but the company also claims several vaccines could be formulated for the patch which are unable to be administered intramuscularly. The Phase II study followed 170 travellers to Mexico and Guatemala. Each volunteer received either two doses of the Iomai vaccine patch or a placebo, two to three weeks apart, with the last dose administered a week before travel. Besides travellers' diarrhoea, Iomai currently has three other product candidates in development using the patch-based formulation which target influenza and pandemic flu. The company plans to start Phase III trails for the travellers' diarrhoea vaccine next year.
