Prominent USC scientist goes on leave amid research misconduct allegations

A prominent neuroscientist at USC is on leave nearly a year after allegations of research misconduct cast doubt on his published work and derailed trials for an experimental stroke treatment.

USC Keck School of Medicine Dean Carolyn Meltzer sent an email to faculty in the department of physiology and neuroscience on Oct. 22, disclosing that professor Berislav V. Zlokovic was on leave “for an indefinite period.�

In the email, Meltzer said that professor Steve Kay would serve as acting director of both the Zilkha Neurogenetic Institute and the department of physiology and neuroscience, positions that Zlokovic formerly held.

A spokesperson confirmed Zlokovic’s leave and Kay’s acting appointments on Monday but declined to provide further details, citing confidentiality surrounding personnel matters. Zlokovic didn’t immediately respond to requests for comment Monday.

Late last year, a group of whistleblowers submitted a report to the National Institutes of Health questioning the integrity of Zlokovic’s research and the safety of an experimental stroke treatment developed by ZZ Biotech, the company he co-founded.

The report identified allegedly doctored images and data in 35 research papers in which Zlokovic was the sole common author. It also questioned findings in the Phase II clinical trials of 3K3A-APC, a drug intended to reduce post-stroke brain bleeds.

The whistleblowers’ findings and news of Zlokovic’s leave were first reported in the journal Science.

On Sept. 26, Houston-based ZZ Biotech officially canceled 3K3A-APC’s clinical trial, according to a notice of withdrawal filed on the government’s database of clinical research studies.

“Any decisions on the future development pathway of 3K3A-APC in stroke will need to wait until the investigations of Dr. Zlokovic are complete,� ZZ Biotech Chief Executive Kent Pryor said Monday. Zlokovic no longer has any managerial or scientific affiliation with the company but remains a minority equity holder as co-founder, Pryor said.

NIH paused the trial in November 2023. It also launched an investigation into Zlokovic and instructed USC to return $1.9 million in funding already supplied for the study, Science reported.

“USC has been cooperating fully with the National Institutes of Health in this matter,� a spokesperson said in response to questions about the trial’s funding. “Now that the study has ended, we will be submitting a final financial report to the NIH.�

Zlokovic is a leading researcher on the blood-brain barrier, with particular interest in its role in stroke and dementia. After joining the USC faculty in 1989, he left and spent 11 years at the University of Rochester before returning to USC in 2011. He was appointed director of USC’s Zilkha Neurogenetic Institute the following year.

He retained his department chair and institute director titles as USC launched an investigation after the whistleblower report.

Since the allegations became public, three of Zlokovic’s hundreds of published research papers have been retracted. Eight more have been issued corrections or expressions of concern, a note journals append to articles when they believe there may be a problem with a paper but have not proved so.

Dr. Matthew Schrag, an assistant professor of neurology at Vanderbilt who co-authored the whistleblower report independently of his work at the university, previously told The Times that he and his colleagues did not find evidence of manipulated data in the drug trial. But given the degree of concern surrounding Zlokovic’s earlier work, he said, a clinical trial relying on his research to treat patients in life-threatening situations deserved further scrutiny.

“When you’re seeing a red flag or a trend in the clinical trial, I would tend to give that more weight in the setting of serious ethical concerns around the pre-clinical data,� Schrag said this year. Schrag didn’t immediately respond to requests for comment Monday.