The FDA has warned Kimera Labs that it can't sell its exosome product for uses outside of its recently secured investigational new drug (IND) application.
In a that was posted to the FDA's website last September, then removed, and then posted again this month, the agency also told the Miramar, Florida-based company that none of its products are the subject of a biologics license application (BLA) -- which it would need to market a biological product like exosomes to treat various conditions.
FDA also pointed out that Kimera "failed to document an investigation into the positive sterility result" for one of its products, XoGloPro, found during a July 2022 inspection, adding that all of the vials had been distributed.
While Kimera was issued an IND for its XoGloPro product in May 2023, FDA acknowledged, the indication was for a phase I/IIa clinical trial evaluating the safety and efficacy of a single intravenous dose of the drug to treat COVID-19 in adults with mild-to-moderate illness, .
But just because the IND is in effect doesn't mean a company can "commercially distribute or test market an investigational new drug," the FDA warned.
"Just because you have one IND doesn't mean you can do all that other stuff," Paul Knoepfler, PhD, of the University of California Davis, who has long tracked stem cell products in the U.S., told . "Their exosomes are [marketed] for so many different things."
In its letter, FDA said Kimera makes two exosome products -- XoGlo and XoGloPro -- as well as an amniotic fluid product called Amnio2X.
The July 2022 inspection found "significant deviations" from current good manufacturing practice (CGMP) requirements, according to the FDA, including failure to establish written procedures to prevent microbiological contamination of its sterile products; failure to establish adequate cleaning procedures; and issues with its purity testing methodology.
That inspection also found the issue with the positive sterility result for a lot of XoGloPro.
"You would have thought those [issues] would have been ironed out before they got an IND," given that the inspection was in July 2022 and the IND was issued in May 2023, Knoepfler added.
The warning letter also noted that because investigators "had some difficulty obtaining unredacted records, including batch records, from you during the inspection," FDA "encouraged" the company to review the agency's policy on circumstances that constitute delaying, denying, limiting, or refusing a drug inspection.
In its October 2022 response, Kimera said it planned to continue to distribute existing inventory through a certain time, according to the warning letter. FDA responded in December 2022 saying it did not agree with that decision "to continue to distribute these products without a BLA or IND in effect."
Kimera said in its February 2023 response to the FDA that it would "cease all distribution of existing batches of XoGlo and XoGloPro by Friday, February 10, 2023" for use outside of its IND. FDA told Kimera that its "continued distribution of your products violates the [Food, Drug, and Cosmetic] FD&C Act and the [Public Health Service] PHS Act."
Kimera said in a press release emailed to that it conducted sterility tests of the XoGloPro lot in question, and that it was free from pathogens. It also shared those data with FDA, the release said.
"We provided FDA with a full response to these alleged pharmaceutical CGMP deviations and will soon file an update on the actions we have taken to conform to drug manufacturing standards," Duncan Ross, PhD, founder and CEO of Kimera Labs, said in the release.
To date, Kimera has not received any reports of adverse events tied to its products, and has recently been approved to conduct a 160-patient clinical trial in a non-hospital ambulatory setting, according to the press release.
This isn't the first letter FDA has sent to Kimera Labs. In April 2020, FDA sent an to Ross and to Douglas Spiel, MD, a "clinical consultant" to Kimera, stating that based on the company's claims on YouTube videos, its products would be regulated as drugs and biological products.
In its warning letter, the FDA also referenced its on exosome products, which it issued after "multiple reports of serious adverse events experienced by patients who were treated with exosome products."
Notably, an outbreak in Nebraska involved around five patients who became seriously ill, including some who developed sepsis. All were given an exosome product derived from C-sectioned placentas, according to a health alert sent by the state to clinicians. Ultimately, the culprit was found to be a product made by Las Vegas-based EUCYT Laboratories.
Exosomes are tiny packets secreted by stem cells, thought to carry proteins as well as RNA to build other proteins. On his stem cell blog, Knoepfler that Kimera makes exosomes from various kinds of cells, including mesenchymal stem cells from birth tissues.
Currently, no exosome products are approved by the FDA. The agency did not return a request for comment from .