Elon Musk’s Nueralink won’t be testing its brain implant on humans any time soon — the U.S. Food and Drug Administration (FDA) has rejected the company’s application.
The agency outlined dozens of issues the company needs to address before human testing, a critical milestone for final product approval, Neuralink employees told Reuters.
Concerns include the device’s lithium battery; the potential for the implant’s tiny wires to migrate to other parts of the brain; and asking if and how the device can be removed without damaging brain tissue, the employees said.
Musk applied in early 2022, but staffers said the company’s co-founder hasn’t solved all the problems yet — even though the billionaire revealed that human trials would begin in November in six months.
Three employees said they were skeptical the company would be able to resolve the issues quickly.
Elon Musk applied for FDA approval to begin human trials of the Neuralink implant. Company employees told Reuters that his application has been rejected
During the hour-long presentation on Nov. 30, Musk said the company had submitted “most of our paperwork” to the FDA, without specifying any formal filings.
But he seemed confident about the six-month timeline.
Neuralink officials acknowledged that the FDA had asked safety questions in what they characterized as an ongoing conversation.
The sources declined to provide Reuters with the agency’s written rejection, a legally confidential document, but described them in an interview.
The company has come under fire in recent months as animal advocacy groups and former employees raise the alarm about animal welfare violations.
Lab notes from staffers who conducted experiments at the University of California Davis (UC Davis) show animal problems with the implants, echoing FDA concerns.
The FDA’s rejection listed dozens of what the agency calls “shortcomings” the company must address before testing in humans, five Neuralink sources said.
The implant features tiny wires that carry electrodes and are attached to the head, but the FDA is concerned that wires could migrate to other brain regions, according to six current and former employees.
The agency outlined dozens of issues the company needs to address before testing it on humans. Concerns include the device’s lithium battery and the potential for the implant’s tiny wires to migrate to other parts of the brain
Neuarlink shared a progress update on his brain chip last November. A monkey named Sake typed with his brain. Sake spoke the welcome tag of the Neuralink event: “Welcome to show and tell,” and that’s when Musk shared the six-month timeline for human trials
Musk is said to have tried to address the problem by testing the implants on dozens of pigs, but with no luck.
Migratory threads would cause inflammation in the brain, impair certain functions and rupture blood vessels, said Victor Krauthamer, a former FDA official for three decades, including a stint as acting director of the office that reviews applications for human brain implants.
And this problem would also hinder the implant’s effectiveness, forcing it to be removed, he and other experts said.
“The wires can do damage because brains are very, very soft and very delicate,” Krauthamer said.
The FDA’s concerns about the battery may also be serious, according to brain device experts.
Neuralink proposed equipping its device with a new charging system with lithium batteries that can be charged remotely.
The agency felt the company needed to demonstrate in animal studies that the battery was highly unlikely to fail, six current and former Neuralink employees said.
Three brain implant experts said that if any part of the device connected to battery power fails, the power could potentially damage brain tissue.
The FDA also questioned whether the device could be removed without damaging brain tissue.
In Neuralink’s November presentation, officials acknowledged the FDA’s concerns but downplayed them.
Engineer Alex Wood-Thomas was asked about the potential danger of removing the device to implant an upgraded device in the future.
He told Reuters that because of the small size of the wires, scars “are so minimal in the brain that they can be removed quite easily.”
Several contributors disputed his characterization as misleading and unsupported by animal studies, according to two Neuralink sources and internal discussions seen by Reuters.
Wood-Thomas declined to comment.
The FDA also raised concerns that the device could overheat and potentially damage tissue.
Neuralink may have all the concerns raised by the FDA, industry experts and regulatory authorities said.
If the FDA has persistent minor issues with a company’s device, the company may be able to move forward with a slower, phased trial, the experts said.
According to two people familiar with the discussions, the agency has suggested such a path could work for Neuralink, with fewer subjects implanted at the beginning and more tested months later.
Still, one source said the proposal disappointed Neuralink because it could delay progress toward final FDA approval.
The news of the rejection follows several investigations into Neuralink, most recently by the U.S. Department of Transportation (DOT) earlier this month.
The probe comes in response to allegations from the Physicians Committee of Responsible Medicine (PCRM) that Musk’s company removes unsafely packaged and displaced implants from the brains of potentially infected monkeys.
Neuralink chief surgeon, Matthew MacDougall, conducted experiments on brain implant in animals, lab notes show
PCRM, an animal welfare advocacy group, wrote to Secretary of Transportation Pete Buttigieg to warn him about data it obtained from the University of California (UC) Davis on the matter, according to Reuters.
The letters state that the implants have not been properly disinfected and packaged, so they contain pathogens that can cause serious health problems in infected people.
Neuralink whistleblowers have also come out, revealing that the chief surgeon was conducting “botched experiments” on animals at UC Davis.
DailyMail.com had previously obtained Neuralink lab notes describing how a sealant was applied to the surgical holes, causing the monkey’s brain to swell and bleed
In December, a former Neuralink employee who worked as an autopsy technician told DailyMail.com, “There was no reason to use it.
BioGlue was not FDA approved for brain surgery and could never be transferred to human trials. I can’t see anything not approved for humans being used for primates.”
The neurosurgeon, Matthew MacDougall, developed the BioGlue and instructed staff to administer 15 to 20 milliliters when it should have been three to five, the person familiar with the case said.
Handwritten lab notes show that MacDougall ordered the monkey kept alive for days, even though the animal was “deteriorating postop and was “probably due to cerebral edema.”