ViewPoints: Dubious disclosures for Inovio's COVID-19 vaccine

The latest data from Inovio Pharmaceuticals' COVID-19 vaccine programme haven’t won over any new converts to the value of its vaccine offerings- just as the FDA stepped it to say that it doesn't plan on letting sloppy results advance too quickly in the pandemic fight.

What happened

Inovio's first blush at COVID-19 vaccine data seemed to come up short, with the company's shares dropping as much as 20% after it disclosed that INO-4800 produced "overall immunological responses" in 34 of 36 patients, based on "preliminary data assessing humoral (binding and neutralising) and T cell immune responses."

There were no serious adverse events in the study, which evaluated two doses of INO-4800 administered as two treatments received four weeks apart. There were 10 total adverse events, all of which were Grade 1 and most associated with injection site redness.

The company says it plans to publish the complete results in a medical journal.

What it means

Inovio is only the latest COVID-19 player to follow up on investor enthusiasm with a scant data release; Moderna released top-line Phase I results from its mRNA vaccine programme back in May, and while it has yet to release detailed results from the trial, a Phase III study is expected to start in July now that 300 patients have been enrolled in a Phase II study.

For Inovio, the data disclosure seemed to produce even greater confusion over the company's DNA vaccine candidate, as analysts struggled to make sense of what an "overall immunological response" means in terms of neutralising antibody production and humoral versus T-cell responses.  

The bigger picture

Inovio has already committed to pursuing an emergency use authorisation (EUA) for INO-4800 by the end of the year- where if approved, it would be the first ever company to secure an EUA for a vaccine. (See ViewPoints: Inovio takes preclinical vaccine data to the bank)

However, on top of its troubles with the incomplete data disclosure, new guidance from the FDA may have lowered confidence in an easy path forward for the sector's vaccine aspirations. A guidance document released on June 30 emphasised the agency's interest in vaccine candidates that have run through all the necessary paces for full approval. According to the guidance, "the goal of development programmes should be to pursue traditional approval via direct evidence of vaccine efficacy in protecting humans from SARS-CoV-2 infection and/or disease."

The agency also stipulated that both SARS-CoV-2 infection and severe COVID-19 disease should be included as either primary or secondary endpoints, and "the primary efficacy endpoint point estimate for a placebo-controlled efficacy trial should be at least 50%"- a bar which Jefferies' Michael Yee notes is higher than often seen with influenza vaccines.

The inclusion of both disease and infection prevention as clinical endpoints could be a key factor for some vaccine products in development; animal data from a joint effort between the University of Oxford and AstraZeneca has suggested that the partners' vaccine may produce a reduction in disease severity, rather than total disease prevention. (See ViewPoints: After Moderna vaccine reveal, attention shifts to Oxford and Sinovac)

Next steps

The more-stringent-than-expected attitude from the FDA could be viewed as a refreshing change, where some have feared that early endorsement of treatments like hydroxychloroquine undermined public confidence in drug development- now with the extra political pressure of a US Presidential election in November, perceived by some as a rationale to rubber-stamp treatment and vaccine options in the US.

At the same time, the idea that the agency may not be as flexible as initially thought seemed to trickle through the biotech sector; Jefferies' Michael Yee wrote that the agency was framing a relatively "high bar given the urgency," noting that the FDA "even suggests it will not reduce standards or cut corners."

That said, an EUA would likely to be necessary to hit benchmarks set by the administration's Operation Warp Speed, which has a stated goal of providing 300 million of a safe and effective vaccine by January 2021- a lofty goal even with the use of an EUA.

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