At least one outside expert said the approach could pose security risks. Paul Knoepfler, a stem cell researcher at the University of California at Davis, said that patients with coronaviruses can develop severe reactions where their immune system goes too far by attacking cells in their lungs, causing damaging inflammation. Other cell therapies tested in China are designed to suppress the immune response. He said that one risk with natural killer cells is that they could go the other way, exacerbating respiratory problems “by massively killing patients’ respiratory cells.”
Despite the scarce evidence, Mr. Giuliani became an early recall, interviewing Dr. Hariri on a podcast posted on his website on Saturday, and praising the treatment on Twitter, saying that “this therapy has real potential.” In a tweet on Saturday, he added, “Hopefully F.D.A. may recognize that their cumbersome process designed to keep us safe, if not changed dramatically in times of need, can result in an unimaginable loss of human life. “
Around the same time, Twitter deleted a message from Mr. Giuliani who he said was breaking his rules. The tweet, dated March 27, made unfounded claims about hydroxychloroquine, one of the treatments Mr. Trump supported.
Dr. Hariri said that he had known Mr. Giuliani for years and that the appearance on his podcast was “a friendly conversation between people who know each other and who share a common interest in this particular response to this disease. “
He said he had no business relationship with Mr. Giuliani and that Mr. Giuliani did not represent him in any way, whether he was paid or not. “I have nothing to do with what the mayor tweets or anything else, and I don’t agree or disagree with anything,” he said.
Dr. Hariri said the company would follow the established process to test whether a drug works. “We waited for the F.D.A. to finish their exam, which they did heroically and quickly, “he said.
Wednesday evening – the same day, the F.D.A. approved his trial – Dr. Hariri welcomed the appearance of agency commissioner Dr. Stephen Hahn in the Fox News conservative “The Ingraham Angle”. ” We are fortunate to have Dr. Hahn at the helm“, He tweeted.