Icon Genetics has published a second milestone paper further detailing the remarkable immune responses elicited by the novel norovirus vaccine candidate in a successfully completed phase i clinical study

Halle (Saale), 26 June 2023. Icon Genet­ics GmbH, a whol­ly owned sub­sidiary of Den­ka Co. Ltd, Tokyo, Japan, has pub­lished a sec­ond mile­stone paper in the renowned jour­nal “Fron­tiers in Immunol­o­gy” detail­ing on the remark­able immune respons­es elicit­ed by its norovirus vac­cine can­di­date dur­ing the suc­cess­ful­ly com­plet­ed Phase I clin­i­cal study.
Norovirus­es are respon­si­ble for approx­i­mate­ly 20% of all cas­es of acute gas­troen­teri­tis world­wide and are rec­og­nized as an impor­tant pub­lic health issue. There­fore, an effec­tive vac­cine is need­ed to reduce the glob­al bur­den of gas­troin­testi­nal dis­eases elicit­ed by it. Despite decades of inten­sive research in the field, no licensed vac­cine for pre­vent­ing norovirus dis­ease and ame­lio­rat­ing detri­men­tal health, soci­etal, and eco­nom­ic effects in all age groups is avail­able today.
The report­ed tri­al was a sin­gle-cen­ter, ran­dom­ized, dou­ble-blind, con­trolled study that has been approved by the Bel­gian Health Author­i­ties (Fed­er­al Agency for Med­i­cine and Health Prod­ucts-FAMHP) and run in the Cen­ter for Vac­ci­nol­o­gy (CEVAC) at the Ghent Uni­ver­si­ty Hos­pi­tal (Ghent, Bel­gium). To assess the poten­tial vac­cine, the clin­i­cal tri­al was con­duct­ed on 60 adults. The study vac­cine was a com­bi­na­tion of two dif­fer­ent types of norovirus anti­gens and adds no sub­stances (adju­vants) to increase or mod­u­late the immune response. The results for how well vac­ci­na­tion was tol­er­at­ed and ini­tial assess­ment of immune respons­es were pub­lished in Octo­ber 2022 in “Fron­tiers in Immunol­o­gy”. In the cur­rent pub­li­ca­tion, we focused on addi­tion­al and more detailed analy­sis of immune respons­es elicit­ed by the norovirus vac­cine can­di­date. Results showed that the vac­cine can­di­date elic­its sig­nif­i­cant immune respons­es, with no need for an adju­vant. The vac­cine elicit­ed the pro­duc­tion of IgA anti­bod­ies, which are impor­tant for mucos­al immu­ni­ty and pro­tec­tion from viral infec­tion in the gut were also norovirus infec­tion takes place. Fur­ther­more, the immune response was not only detectable for norovirus anti­gens present in the vac­cine but also for a vari­ety of anti­gens not includ­ed, a very impor­tant find­ing giv­en the com­plex norovirus epi­demi­ol­o­gy involv­ing many dif­fer­ent norovirus types. Final­ly, a sig­nif­i­cant cell-medi­at­ed immune response elicit­ed by the vac­cine can­di­date could be con­firmed which is described as rel­e­vant for pro­tec­tion from oth­er dis­eases elicit­ed by virus­es. The pro­vid­ed data show that Icon Genet­ics’ norovirus vac­cine is a very promis­ing prod­uct can­di­date for pre­vent­ing norovirus gas­troen­teri­tis. Immune respons­es ana­lyzed are on par or even exceed­ing results described for prod­ucts in clin­i­cal devel­op­ment by com­peti­tors. In con­clu­sion, fur­ther stud­ies of Icon Genet­ics’ norovirus vac­cine can­di­date are ful­ly sup­port­ed by the obtained results and need to eval­u­ate effi­ca­cy, opti­mal for­mu­la­tion, and anti­gen com­po­si­tion.
For its can­di­date norovirus vac­cine Icon Genet­ics pro­duces norovirus-like par­ti­cles (VLPs), that mim­ic the struc­ture of the virus but are not infec­tive, in high yield using the company’s mag­nI­CON® tech­nol­o­gy. The pro­pri­etary mag­nI­CON® tech­nol­o­gy uti­lizes tobac­co plants for the rapid, scal­able, and envi­ron­ment-friend­ly pro­duc­tion of diverse recom­bi­nant pro­teins to serve the diag­nos­tics and bio­phar­ma­ceu­ti­cals mar­kets. Unlike with old­er GMO tech­nolo­gies, Icon Genet­ics’ pro­duc­tion host plants are not genet­i­cal­ly mod­i­fied in a sta­ble man­ner but are rather tem­porar­i­ly instruct­ed to pro­duce a pro­tein of inter­est by treat­ment with a bac­te­r­i­al vec­tor car­ry­ing the genet­ic blue­print for the prod­uct. The tar­get pro­teins are pro­duced indoors and are sub­se­quent­ly extract­ed in pure form from the plants’ leaves. The norovirus vac­cine can­di­date for the cur­rent clin­i­cal study was pro­duced at Icon Genet­ics’ pilot-scale facil­i­ty in Halle/Saale, Ger­many.