Meiji Seika Pharma to supply Japan with self-amplifying mRNA Covid-19 vaccine in fall/winter of 2024

Mei­ji Sei­ka Phar­ma an­nounced Tues­day that it plans to ap­ply in Japan to sell its self-am­pli­fy­ing mR­NA vac­cine for Covid-19 and sup­ply it for the fall/win­ter sea­son.

An in­ter­im analy­sis of a Phase 3 clin­i­cal tri­al of the vac­cine ARCT-2301, or Kostaive, showed non-in­fe­ri­or­i­ty in im­muno­genic­i­ty com­pared to Pfiz­er and BioN­Tech’s pre­vi­ous­ly ap­proved bi­va­lent mR­NA vac­cine Comir­naty. Kostaive is a self-am­pli­fy­ing mR­NA vac­cine cre­at­ed based on the tech­nol­o­gy of Arc­turus Ther­a­peu­tics. ARCT-2301 is a bi­va­lent vac­cine based on the orig­i­nal strain and Omi­cron BA.4-5.

The sub­jects were healthy adults aged 18 and old­er who had re­ceived 3-5 dos­es of the ap­proved mR­NA vac­cine, with at least three months hav­ing passed since the last dose. In the tri­al, 927 sub­jects were ran­dom­ized to the ARCT-2301 group (463 sub­jects) or the Comir­naty group (464 sub­jects), and re­ceived an ad­di­tion­al 0.5 mL (5 μg) dose of ARCT-2301 or 0.3 mL (30 μg) dose of Comir­naty.

The pri­ma­ry im­muno­genic­i­ty end­points were the non-in­fe­ri­or­i­ty ver­i­fi­ca­tion of the geo­met­ric mean titer (GMT) and serore­sponse rate (SRR) of neu­tral­iz­ing an­ti­bod­ies against Comir­naty at day 29. The ob­ser­va­tion pe­ri­od was ap­prox­i­mate­ly 180 days. Side ef­fects, as well as the ef­fi­ca­cy based on the in­ci­dence of Covid-19, were al­so eval­u­at­ed.

In this in­ter­im analy­sis, ARCT-2301 demon­strat­ed sig­nif­i­cant­ly high­er im­muno­genic­i­ty, in­clud­ing GMT and SRR of neu­tral­iz­ing an­ti­bod­ies against the Omi­cron BA.4-5 and orig­i­nal strains, com­pared to Comir­naty. The in­ci­dence of spe­cif­ic ad­verse events with ARCT-2301 was com­pa­ra­ble to Comir­naty, and all events were mild or mod­er­ate in sever­i­ty. The in­ci­dence rates of all ad­verse events were al­so sim­i­lar be­tween the groups.

“It has been con­firmed that high im­muno­genic­i­ty and safe­ty can be re­pro­duced even if the man­u­fac­tur­ing strain serv­ing as the ba­sis for the vac­cine is changed due to the emer­gence of a new SARS-CoV-2 vari­ant. We be­lieve this es­tab­lish­es the Kostaive plat­form,” said Dai­kichi­ro Kobayashi, the CEO Mei­ji Sei­ka’s phar­ma­ceu­ti­cal di­vi­sion. “We ex­pect this plat­form to be ap­plic­a­ble even in cas­es where the preva­lent strain un­der­goes a ma­jor mu­ta­tion or its path­o­genic­i­ty changes sig­nif­i­cant­ly.”

Based on the tri­al re­sults, the com­pa­ny plans to de­ter­mine the man­u­fac­tur­ing strain in line with the vac­cine strain (preva­lent strain) se­lec­tion by the World Health Or­ga­ni­za­tion, Min­istry of Health, La­bor and Wel­fare, and Na­tion­al In­sti­tute of In­fec­tious Dis­eases, and ap­ply for par­tial change ap­proval for Kostaive in prepa­ra­tion for the 2024 fall/win­ter sea­son.

“From fall 2024 on­ward, we will sup­ply a vac­cine based on the new preva­lent strain. Ap­prox­i­mate­ly 28 mil­lion peo­ple in Japan re­ceived vac­ci­na­tions that start­ed in fall 2023, so we ex­pect around 30 mil­lion peo­ple to re­ceive vac­ci­na­tions an­nu­al­ly go­ing for­ward,” said Kobayashi.

The com­pa­ny plans to man­u­fac­ture and sup­ply 4 mil­lion dos­es of Kostaive for the 2024 fall/win­ter sea­son. It is an­tic­i­pat­ed that the vac­cine will be kept un­der frozen con­di­tions un­til it reach­es vac­ci­na­tion sites or hos­pi­tals, where it will be switched to re­frig­er­at­ed stor­age.

The com­pa­ny is con­sid­er­ing a price that falls with­in the range en­vi­sioned by the Min­istry of Health, La­bor and Wel­fare.

The com­pa­ny has al­ready be­gun man­u­fac­tur­ing prepa­ra­tions af­ter se­lect­ing mul­ti­ple preva­lent strains. It ap­pears that, at this time, it is un­de­cid­ed whether the Kostaive vac­cine will be mono­va­lent or bi­va­lent for the par­tial change ap­pli­ca­tion, but ac­cord­ing to the com­pa­ny spokesper­son, “The pos­si­bil­i­ty of it be­ing a bi­va­lent vac­cine con­tain­ing the orig­i­nal strain is con­sid­ered quite low.”