Why did J&J hit pause on its COVID-19 vaccine trial? Stay tuned, execs say

J&J
Pausing a trial due to unexpected illnesses is not uncommon, especially in large studies like this one, said Johnson & Johnson Chief Financial Officer Joseph Wolk. (Raysonho/CC0)

Johnson & Johnson has put its late-stage COVID-19 vaccine study on hold because a patient has fallen ill. The pause comes just weeks after the company kicked off the 60,000-patient study and about a month after AstraZeneca suspended its own COVID-19 study for similar reasons.

J&J paused the study due to an “unexplained illness in a study participant,” Stat reported Monday evening.

“Right now, we’re waiting for the independent drug safety monitoring board (DSMB) to do their analysis … We still don’t know whether it’s in the placebo arm or the vaccination arm,” J&J Chief Financial Officer Joseph Wolk said on CNBC Tuesday morning.

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Pausing a trial because of unexpected illnesses is not uncommon, especially in large studies like this one, Wolk said, a sentiment echoed by Mathai Mammen, M.D., Ph.D., the R&D chief at J&J’s Janssen unit, on the company’s third-quarter earnings call.

“We were informed of unexpected illness Sunday evening. DSMB was informed immediately,” Mammen said, adding that there's “a very defined and well thought through process at J&J that follows high standards,” and the company “followed all of that to the letter here.”

“It’ll be a few days at minimum for the right set of information to be gathered and evaluated,” Mammen said.

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AstraZeneca paused its own study early last month because a patient developed transverse myelitis, or inflammation of the spinal cord that can be triggered by infections. It restarted the trial in the U.K. a week later, with sites in other countries getting back on track soon after. It’s still on hold in the U.S.

Both J&J and AstraZeneca are part of Operation Warp Speed, the U.S. government's effort to deliver 100 million doses of a viable COVID-19 vaccine by January 2021. And that's not all they have in common—both are developing adenovirus-based vaccines, unlike Warp Speed peers Pfizer and Moderna, which are working on mRNA-based jabs.