AstraZeneca trial was stopped today. I thought I could give you some context…
The #1 priority of public health studies is safety. As you can imagine, a study lands on a spectrum of “less risky” to “very risky” for participants. A “less risky” study, for example, would be the survey I sent earlier today. We didn’t ask you to take a pill and didn’t even asking you to provide your name (which could then be hacked). There is a high likelihood that nothing will happen to you because you took the survey. A riskier study is a Phase III vaccine trial (like AstraZeneca).
Depending on the risk of a study, a scientist must get approval from 1 or 2 external review boards. These boards are made up of people that aren’t connected, in any way, with the study. Meaning… they aren’t affected by the success of a study (professionally or financially). This ensures that studies are “double checked” for safety without the influence of conflicts of interest. This is an essential process in science. The two boards are…
- Institutional Review Board. Every study needs this BEFORE a study starts. It’s usually made up of people with an ethics background or specialists in the field. Scientists HAVE to get this stamp of approval before they can start.
- Data Safety Monitoring Board (DSMB). Only “risky” studies need this. This board is typically made up of 4-10 people and are ethicists, statisticians, medical specialists, and even community members. This board checks for safety DURING the study. They make the rules on when to stop a trial. They also meet on a regular basis, have access to the data throughout the trial, and knows who got the placebo and who didn’t.
The AstraZeneca Phase III trial has both of these boards. Today, the #2 board (DSMB) decided to pause the study.
The DSMB can pause OR stop a study for three reasons:
- Overwhelming positive effect of a drug (They stop so the placebo participants can start getting the effective drug)
- A negative effect of a drug (adverse event, serious side effect, hospitalization, or death)
- Futility (the study can’t complete what it promised OR it isn’t working as well or better than existing approved drugs). This is what happened with a couple of the hydroxychloroquine studies that ended early.
The AstraZeneca trial was stopped because of reason #2. A participant had a serious adverse event or serious side effect while they were enrolled in the study. This could OR could not mean the vaccine caused the side effect. The DSMB needs more time to carefully investigate what happened and if it was, in fact, related to the vaccine. After the investigation, they could recommend to stop the Phase III trial altogether or continue the trial.
This is nothing to worry about yet, but rather an indication that the safety measures are properly in place and working (which is always reassuring). Remember, 42% of vaccines fail in Phase III for varying reasons. We won’t know about the success or failure of this one for a while.
PS this is probably a LOT more than you ever wanted to know. This is also a rapidly evolving event. As developments come out, I’ll try and update you from a scientific perspective. For those of you that are looking for the trial marker, here it is: https://clinicaltrials.gov/ct2/show/NCT04516746 Photo by KIRSTY WIGGLESWORTH/AP