Arcturus Phase I/II corona vaccine trial results prove ‘underwhelming’

Israel signed with Arcturus only weeks after signing with Moderna. However, Moderna’s vaccine has already been approved for emergency use by the American Food and Drug Administration.

A scientist conducts research on a vaccine for the novel coronavirus (COVID-19) at the laboratories of RNA medicines company Arcturus Therapeutics in San Diego, California, U.S., March 17, 2020.  (photo credit: BING GUAN/REUTERS)
A scientist conducts research on a vaccine for the novel coronavirus (COVID-19) at the laboratories of RNA medicines company Arcturus Therapeutics in San Diego, California, U.S., March 17, 2020.
(photo credit: BING GUAN/REUTERS)
The results of a Phase I/II trial of the coronavirus vaccine being developed by Arcturus Therapeutics received tepid reviews on Tuesday, causing its stock to plummet.
 
Israel purchased four million doses of Arcturus’s messenger RNA (mRNA) vaccine candidate, LUNAR-COV19, back in July. The company’s CEO, Joseph Payne, told The Jerusalem Post in November that Israel is “first in line, or at least in the front position of that line” – along with Singapore – to receive the vaccine, if approved.
 
The California-based company has been conducting its Phase I/II study through Singapore’s Duke-NUS Medical School. Some 106 people participated in the trial that showed 100% immunogenicity, meaning antibodies were developed against the novel coronavirus, for the 78 people who received the vaccine – 28 people received a placebo. However, the levels of antibodies were largely below what the vaccines from Moderna and Pfizer were able to generate.
 
As such, some analysts referred to the results as “underwhelming.”
 
LUNAR-COV19 utilizes the company’s “Self-Transcribing and Replicating mRNA” technology and its LUNAR lipid-mediated delivery to produce the vaccine, making it similar to Moderna’s and Pfizer’s vaccines. But Payne said his company hoped to be able to produce a low- and one-dose vaccine, which would improve compliance and save money.
 
Israel signed with Arcturus only weeks after signing with Moderna. However, Moderna’s vaccine has already been approved for emergency use by the American Food and Drug Administration and is expected to arrive in Israel by March. Israel ordered six million doses of the Moderna vaccine, enough to inoculate three million Israelis.
 
Netanyahu rarely, if ever, refers to Israel’s deal with Arcturus.
 
Payne told the Post that the cost of the vaccines to Israel is expected to be around $275 million. He also noted that, unlike the Pfizer and Moderna vaccines that have been arriving in multiple smaller shipments, if Arcturus is approved for use, the vaccines would ship to Israel in at most two shipments.
 
Despite the lower level of antibodies, Arcturus received approval from Singapore Health Services to proceed with a Phase II study, which will evaluate both the hopeful single dose regime and a prime-boost regime that is similar to the Pfizer and Moderna models.
 
The Phase II trial will include 600 participants. The data from that trial should be available in early 2021. If successful, a phase III study would take place in Q2 2021.
 
Arcturus has been in the vaccine space for several years. It has close ties with Israel because it merged with Israel’s Alcobra Ltd. in 2017. There are still a handful of Israelis working among the company’s staff of 120.