On at least four occasions since 2019, Elon Musk has predicted that his medical device company, Neuralink, would soon start human trials of a revolutionary brain implant to treat intractable conditions such as paralysis and blindness.
Yet the company, founded in 2016, didn’t seek permission from the US Food and Drug Administration until early 2022 — and the agency rejected the application, seven current and former employees told Reuters.
The rejection has not been previously reported. In explaining the decision to Neuralink, the agency outlined dozens of issues the company must address before human testing, a critical milestone on the path to final product approval, the staffers said.
The agency’s major safety concerns involved the device’s lithium battery; the potential for the implant’s tiny wires to migrate to other areas of the brain; and questions over whether and how the device can be removed without damaging brain tissue, the employees said.
A year after the rejection, Neuralink is still working through the agency’s concerns. Three staffers said they were sceptical the company could quickly resolve the issues — despite Mr Musk’s latest prediction at a November 30 presentation that the company would secure FDA human-trial approval this spring.
Neuralink has not disclosed details of its trial application, the FDA’s rejection or the extent of the agency’s concerns. As a private company, it is not required to disclose such regulatory interactions to investors.
During the hours-long November presentation, Mr Musk said the company had submitted “most of our paperwork” to the agency, without specifying any formal application, and Neuralink officials acknowledged the FDA had asked safety questions in what they characterised as an continuing conversation.
Such FDA rejections do not mean a company will ultimately fail to gain the agency’s human-testing approval. But the agency’s pushback signals substantial concerns, according to more than a dozen experts in FDA device-approval processes.
Still, Mr Musk retains the full confidence of many loyal Neuralink staffers and some industry investors, who point to his past successes in taking on extreme challenges as the founder of Tesla and rocket-builder SpaceX.
“I definitely would never bet against him,” said Bob Nelsen, co-founder of venture capital firm ARCH Venture Partners, who said he invested personal money into Neuralink. “If he has some bumps in the road with Neuralink, or any other thing, he’ll regroup and figure it out. Just think about it: Those are hard industries with huge safety barriers — cars and rockets.”
In public comments over the years, Mr Musk has detailed a bold vision for Neuralink: Both disabled and healthy people will pop into neighbourhood centres for speedy surgical insertions of devices with functions ranging from curing obesity, autism, depression or schizophrenia to web-surfing and telepathy.
Eventually, Mr Musk has said, such chips will turn humans into cyborgs who can fend off the threat from sentient machines powered by artificial intelligence.
“I could have a Neuralink device implanted right now, and you wouldn’t even know,” Mr Musk said at the November 30 presentation, a live-streamed “show and tell” event, drawing laughs from the crowd. At another public company event in 2020, he said: “You’ll be able to save and replay memories …. The future is going to be weird.”
Such high-flying ambition has contributed to Neuralink’s estimated worth of more than $1 billion, far higher than its competitors, according to four people familiar with the private valuation.
Neuralink officials have publicly vowed to address any FDA concerns.
Mr Musk made headlines late last year when he said he was already so confident in the devices’ safety that he would be willing to implant them in his own children.
Mr Musk also has said Neuralink would restore full mobility to paralysed patients.
Mr Musk’s public claims and well-known impatience pose a critical test for the FDA in balancing demands for speedy review with the diligence required to ensure safety and efficacy, said Kip Ludwig, former programme director for neural engineering at the US National Institutes of Health, a federal agency.
The FDA in recent years has faced pressure from Congress to accelerate reviews but also criticism over controversial approvals, such as its 2021 authorisation of an Alzheimer’s treatment without conclusive proof of efficacy.
Industry players closely watching Neuralink’s development have long expected a collision between Mr Musk and the FDA, Mr Ludwig said, as the billionaire pushes Neuralink to quickly navigate regulatory reviews.
“Everybody in the industry was saying: ‘Oh my God, they’re going to run straight into a brick wall,’” Mr Ludwig said of Mr Musk’s bid for FDA approval. “Neuralink doesn’t appear to have the mindset and experience that’s needed to get this to market anytime soon.”
Without commenting on Neuralink, the FDA said it upholds high standards in vetting all brain implants even as it aims to speed reviews.
“Innovation and safety are not an either-or scenario,” said Owen Faris, who helps oversee the FDA’s Office of Product Evaluation and Quality.