A friend who was not a physician once told me drug companies were “stupid” since most therapies fail in advanced clinical trials after spending lots of money. I responded that given the complexity of human biology, it is almost impossible to anticipate the bad effects that cause most drugs to fail!
Therefore, it is not surprising that two COVID-19 vaccine trials and one therapeutic antibody trial have now been stopped over potential safety concerns.
The vaccine trials that were stopped include AstraZeneca (which was placed on formal clinical hold by the FDA) and Johnson & Johnson, which paused its vaccine trial due to “an unexplained illness in a study participant” as first reported by Stat News.
In addition, a US-government-sponsored trial for Eli Lilly’s antibody therapy against COVID-19 was paused due to a “potential safety concern,” according to emails sent to testing sites on Tuesday. This antibody was hoped to neutralize the virus to help patients survive the infection.
Unlike the AstraZeneca vaccine trial, where a patient suffered a severe neurological inflammatory syndrome after the second dose of the vaccine, the situations surrounding the other two clinical trial suspensions have not been disclosed.
Of interest, the Johnson & Johnson vaccine is similar to the AstraZeneca vaccine, as both are modified adenoviruses that have been given the gene for the spike protein from SARS-CoV-2. AstraZeneca’s vaccine is a chimpanzee adenovirus while Johnson & Johnson’s vaccine is based on human adenovirus type 5.
Johnson & Johnson and Eli Lilly stated that their trials were stopped by internal review boards and not by the FDA. These review boards monitor the trial to make sure that any questionable problem is addressed immediately. Johnson & Johnson made a statement that it was “learning more about this participant’s illness, and would gather all the facts before sharing additional information.” Eli Lilly had no further comment.
The stoppages are not surprising given that these trials were testing approaches to COVID-19, an essentially new disease where there is no FDA-approved vaccine or therapy. Added to this, most of the approaches for vaccines against this disease supported by “Operation Warp Speed” are entirely new and have not been used in prior vaccines for human beings.
The potentially more serious stoppage is with the Eli Lilly trial, which was launched in August, to test a monoclonal antibody against the COVID-19 virus on 300 patients hospitalized with Covid-19. (Note: this approach is similar to the two monoclonal antibodies in Regeneron’s antibody cocktail, although no issues have been reported in that company’s trials).
Results released last month from another trial of the Eli Lilly antibody in 450 patients suggested patients receiving the treatment had a 72% lower risk of being hospitalized or admitted from an emergency room, compared to those taking the placebo. Eli Lilly filed for emergency use authorization (EUA) from the FDA last week. This will certainly put that application on hold.
Again, it is not surprising that these trials will generate safety concerns. The good news is that they are being recognized and the trials halter no matter what the stakes are for the companies. The FDA trial system is working.