Synchron pauses trial of its second-generation Stentrode brain implant

Synchron has paused clinical trials of its second-generation Stentrode device due to signal lead issues, while restructuring the company and building a new team in San Diego.

Issues halt second-generation trials

Brooklyn-based brain implant startup Synchron has paused clinical trials of its second-generation device. According to Wired, the implant fell short of performance expectations in its first participants. The company is also restructuring, cutting jobs, downsizing its New York operations, and setting up a team in San Diego for an entirely new device.

This generation features fewer electrodes and connects fully wirelessly via Bluetooth. Multi-site US trials kicked off this spring, with additional sites in Australia and Canada. Several participants have already received the implant. However, trial sites recently stopped enrolling new patients, according to unnamed sources.

Synchron said it voluntarily paused the trial after discovering performance issues with the lead, the cable that transmits signals from the Stentrode to the implanted electronics unit. The company stressed that the issue is not with the Stentrode, that no safety concerns have been reported, and that this was an internal decision rather than an FDA mandate. Two of the five US trial sites contacted by Wired confirmed that patient recruitment is on hold. A coordinator stated the pause was unrelated to safety.

A new direction for Synchron

The company has brought lead design and manufacturing in-house. Instead of merely fixing the lead, Synchron plans to upgrade the entire Stentrode system before resuming enrollment. These trials are critical as a stepping stone toward a larger pivotal trial, a prerequisite for commercial FDA approval. CEO Tom Oxley maintains that the Stentrode has the potential to become a leading therapy.

The Stentrode is a stent-like mesh tube inserted into the jugular vein at the base of the neck and guided via catheter to the motor cortex. This approach avoids open-skull surgery. The first generation connected through external wiring placed on the chest. Ten volunteers across the US and Australia have used the device to send emails, text, browse the web, shop, and bank using their thoughts. They were also able to control Amazon Alexa, an iPad, and Apple's Vision Pro without hands or voice.

San Diego will handle the design and manufacturing of both the lead and the upgraded Stentrode, alongside an unannounced device described as reaching beyond blood vessels. Oxley previously noted that the company aims to develop devices capable of accessing multiple brain regions simultaneously, supporting more complex, natural functions than simply moving a cursor or clicking.

The brain-computer interface race

The sector is expanding rapidly, with capital pouring into both implantable and wearable devices. Synchron was estimated to be valued at nearly 1 billion USD following a 200 million USD funding round last fall. The company is backed by Khosla Ventures, alongside investment funds tied to Bill Gates and Jeff Bezos.

Elon Musk's rival Neuralink was reportedly valued at up to 42 billion USD in secondary transactions as of this summer. In 2024, its device encountered an issue with its first volunteer, Noland Arbaugh. The coin-sized implant sits in the skull, with 64 flexible threads inserted into the brain. Weeks after implantation, several threads retracted from brain tissue, causing him to lose cursor control. Neuralink compensated for the retracted threads and restored control by adjusting its signal-recording algorithms.

AI is accelerating the field, as models decode brainwave patterns faster and more accurately than traditional algorithms. Merge Labs, a brain-computer interface company co-founded by OpenAI CEO Sam Altman, launched in January with 252 million USD in funding. OpenAI contributed part of the capital, and the two entities are collaborating on developing AI models.

Source: Wired

Reviewed by: Hero Association