Johnson & Johnson’s (NYSE:JNJ) late-stage coronavirus vaccine was paused after a participant reported an "adverse event" about 36 hours earlier, the company’s chief financial officer said Tuesday.
The pause will allow the data and safety monitoring board to thoroughly investigate the unexplained illness, the company said.
J&J confirmed to STAT News on Monday that a "pausing rule" in the 60,000-patient clinical trial had been met, but declined to provide further details on the patient.
J&J began its phase three trial testing of its potential coronavirus vaccine last month, becoming the fourth drugmaker backed by the Trump administration’s Covid-19 vaccine program Operation Warp Speed to enter late-stage testing.
J&J has said it is using the same technologies it used to develop its experimental Ebola vaccine. It involves combing genetic material from the coronavirus with a modified adenovirus that is known to cause common colds in humans. Preclinical studies have shown the potential vaccine can generate a promising response in nonhuman primates and hamsters.
J&J isn’t the first frontrunner in the race for a vaccine to halt a late-stage trial due to an unexplained illness.
AstraZeneca (NYSE:AZN) announced on Sept. 8 that its trial had been put on hold due to an unexplained illness in a patient in the United Kingdom. The patient is believed to have developed inflammation of the spinal cord, known as transverse myelitis. The trial has since resumed in the U.K. and other countries, but is still on hold in the United States.
JNJ shares slid $2.28, or 1.5%, to $149.57.
