Moderna Finalizes Plan, Dose for Phase 3 Test of mRNA COVID Vaccine

Xconomy Boston — 

Less than a month after reporting preliminary early-stage data for its experimental vaccine for the novel coronavirus, Moderna has finalized the plan for a Phase 3 test.

The study, set to begin next month, is targeting enrollment of about 30,000 volunteers, Moderna (NASDAQ: MRNA) announced Thursday. Those patients will be randomly assigned to receive either the vaccine candidate, mRNA-1273, or a placebo. The main goal of the study will be preventing the symptoms of COVID-19 disease. Secondary goals include prevention of a severe form of the disease—defined as the need for hospitalization—as well as prevention of infection by the novel coronavirus. The Cambridge, MA-based biotech said this clinical trial plan is based on feedback it received from the FDA.

Moderna says it expects the study will be done in partnership with the National Institute of Allergy and Infectious Diseases (NIAID). The company’s announcement comes one day after the Wall Street Journal reported that the federal government’s “Operation Warp Speed” program plans to conduct late-stage tests of COVID-19 vaccine candidates from Moderna, AstraZeneca (NYSE: AZN), and Johnson & Johnson (NYSE: JNJ).

The federal plan puts government backing behind three different vaccine approaches. Moderna’s vaccine uses messenger RNA (mRNA) to deliver the genetic instructions that get a person’s cells to make the spike protein found on the surface of the novel coronavirus. That protein by itself won’t cause COVID-19 infection but it’s hoped that it will prompt an immune response sufficient to give a patient immunity.

AstraZeneca’s vaccine candidate, AZD1222, is based on research from the University of Oxford. That vaccine is made from a weakened version of a virus that causes the common cold. This virus has been engineered to carry genetic material from the novel coronavirus intended to elicit an immune response. Last month, AstraZeneca and the Biomedical Advanced Research and Development Authority (BARDA) announced a partnership under which the federal agency will provide up to $1.2 billion to support the company’s research and development of its vaccine candidate.

The Johnson & Johnson COVID-19 vaccine candidate, Ad26.COV2-S, recombinant, uses the same technology that the company used to develop its Ebola vaccine. J&J conducted its COVID-19 vaccine research in partnership with BARDA. On Wednesday, the company announced an accelerated timeline for Phase 1/2a tests of its vaccine candidate, which is now expected to start in the second half of July.

Anthony Fauci, director of the NIAID, told attendees of the Biotechnology Innovation Organization’s annual meeting this week that he expects that the race for a COVID-19 vaccine will produce “more than one winner.” That’s because the global need for vaccination requires billions of doses. An additional vaccine contender is coming from BioNTech (NASDAQ: BNTX), which is developing mRNA vaccine candidates under a partnership with Pfizer (NYSE: PFE). The Wall Street Journal reported a candidate from that partnership could start Phase 3 testing in July.

Moderna’s Phase 3 clinical trial for mRNA-1273 will proceed even as the Phase 2 testing is ongoing. Two weeks ago, Moderna dosed the first patient in the mid-stage study, which is targeting enrollment of 600 volunteers. Participants will be randomly assigned to receive a 50 microgram dose, a 100 microgram dose, or a placebo. Patients will receive two doses given 28 days apart. Following the second vaccination, the study will follow patients for 12 months. Moderna on Thursday said that the first group of 300 adults, age 18 to 54, is fully enrolled.

Speaking last month on a conference call last month to discuss the Phase 1 results, Moderna Chief Medical Officer Tal Zaks acknowledged that Phase 3 would proceed before Phase 2 finished. He said that the mid-stage test would substantiate safety data produced from the Phase 1 study and better quantify the immune response that was observed. The Phase 3 study will test the 100 microgram dose of mRNA-1273 vaccine, which was the middle of three doses that were evaluated in Phase 1. Moderna says that this dose was chosen as the one best suited to maximize the immune response while minimizing side effects.

Moderna says it has completed manufacturing of vaccine required to start the late-stage test. The company expects to be able to produce about 500 million doses per year. The company’s manufacturing capability combined with that of partner Lonza is expected to boost the production capacity for mRNA-1273 to up to 1 billion doses per year starting in 2021.

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