Spinal cord stimulation to treat pain has long been associated with mixed efficacy and substantial side effects such as paresthesia, which is an unpleasant tingly or prickly sensation. Redwood City, Calif.-based Nevro Corp. famously has built a multi-billion-dollar business on next-gen, pain neurostimulation technology that improves efficacy and reduces side effects. Sommerville, Mass.-based Micro-leads Medical Inc. hopes that it could be next in successfully further refining spinal cord stimulation.
It has raised a $10 million financing to back additional development of its HD64 implantable therapy system, as well as to start a clinical trial. The National Institutes of Health contributed to the funding as part of its Helping to End Addiction Long-Term (HEAL) Initiative, as did undisclosed private investors. It delivers electrical stimulation to twice as many pain fiber locations on the spinal cord as existing technology, which is expected to offer more localized and side-effect free treatment of chronic low-back pain and focal pains of the trunk and extremities.
“All these companies are trying to come up with, in some ways, pulse generator solutions like: What can we do to make the software a little better? Can we make the device measure something and then do something? Is there something we can do to change the waveform? But, really, in the field of neuromodulation what makes one device better than another is how efficient the lead technology is and does it deliver the energy where it needs to be for maximum clinical efficacy,” Micro-leads CEO Bryan McLaughlin told BioWorld MedTech. “So, delivery is king in terms of providing better therapy.”
“Most devices, including Nevro, they're all using very arcane delivery techniques with percutaneous leads. Almost every manufacturer from Medtronic to Invectra to others all use the same percutaneous leads, which are these crude tools,” he continued. “That's where our Micro-lead, our HD64, comes in is we've actually tried to make a leap on what you can do in terms of the actual delivery of the therapy to the anatomy. So, I think you could have both worlds you could provide great waveforms and deliver them to those targeted fibers that the cord in a more focused and selective way and probably even improve upon the waveforms.”
McLaughlin should understand the latest in spinal cord stimulation technology trends, prior to heading Micro-leads he was the engineering director for active implantable devices in business development at Glaxosmithkline. That group transitioned to become part of bioelectronics spinout Galvani Biosciences Ltd. in late 2016.
The Micro-leads system HD64 is thus named because it has 64 therapy points where it can connect to the spinal cord. The current systems typically have only about 16 therapy points, with Marlborough, Mass.-based Boston Scientific Corp. having a 32 therapy point system. The idea is that the more connection points to the spinal cord, the more precisely physicians can fine tune therapy location, thereby improving efficacy and reducing side effects.
He noticed that the best surgeons will typically test the therapy with an awake patient during surgery, in addition to testing with an external system prior to a surgical procedure, to ensure the correct placement of the therapy points.
How it works
HD64 can increase the number of therapy points without increasing the number of bulkier wires that must extend from the pulse generator – and are typically detectable under a patient’s skin. That’s because each lead has a tiny device embedded in it that helps to transmit the signal.
“We came up with a very flexible, kind of conformal way of making leads. But, more importantly, the leads are active in nature,” explained McLaughlin. “So, what I mean by that is there's a tiny, watertight medical device that's kind of embedded into lead itself. It's like a little series of lightbulb switches. When the pulse generator wants to deliver therapy to this corner or that corner, it sort of turns on switches to the area that it wants to send it.”
“It transmits through this little device. That active technology has never been done and that's what enables us to use a small number of the kind of wires that go under the skin and up to the spinal cord,” he continued. “So, we doubled the therapy points, but we don't double the number of wires that are running under the patient’s skin. That's the big innovation.”
There are typically two to four, to as many as eight of these larger wires that traverse from the pulse generator to the spinal cord and are visible under the patient’s skin, he explained.
Micro-leads aims to start an intraoperative feasibility trial in June, testing different parts of the spinal cord with its device during patients getting operations for other device implants. It plans to start that in January, as well as to advance its manufacturing.
Then it is aiming for a short-term, external trial in about 18 to 24 months for a device that will test if the implanted version is likely to work. After that, a chronic pain trial with HD64 is expected to follow once manufacturing is sufficient to handle roughly 20 subjects in an initial trial that would be at least 24 months away.
Micro-leads found itself in the right place at the right time with the right technology to secure financing from NIH’s HEAL Initiative.
“We were working on HD64 and the opioid crisis had not yet politically become a funded effort. So, we asked the NIH: Do you have any opportunities? Are there any places that something is available for something to try and help with the opioid crisis? They asked us to submit the work under the Brain Initiative because there’s a lot of funding there, but there were some difficulties,” McLaughlin said. “Then we were in the middle of a political, congressional climate change and money became available for treating chronic pain and we are relatively well known in the field.”