David Hovda, CEO of Simplify Medical, discusses the company's history with artificial disc replacement development and where he sees the motion preservation market headed in the future.
Q: What makes the Simplify Medical disc unique?
David Hovda: It is a PEEK-on-ceramic design, and we picked these materials primarily for increased durability to avoid metal wear if possible. We have a retention ring that is machined into the superior endplate, and the core can then translate within that ring. We've never had a core move out of the disc, and many people are surprised at just how small the disc in the spine is. We are encouraged by how well the patients are doing and are excited to see longer-term results.
Q: This disc has been in development for a while. What makes you confident that it's the wave of the future?
DH: We learned a lot in our previous clinical trials for the Kineflex and Kineflex|C discs. We took the lessons we learned and critically evaluated our results and incorporated these lessons into our Simplify Disc.
For example, we showed superiority to fusion with our predecessor disc, but men did better than women. Both we and the FDA wondered why that was. We did quite a bit of work, and, after we enrolled the clinical trial, we realized that the lowest available height disc was too tall compared to the average native disc height of our patients, which would disproportionately affect women’s smaller anatomies.
In the early days of disc replacement, everyone wanted to figure out the height. We started at the height of a fusion spacer. But during fusions, you want to stretch out that space and stop motion, and the fact of the matter is, the average cervical disc height is 4 mm. But if you look at other companies, the average cervical disc height is 6 or 7 mm. We worked really hard to come up with a design that ranges from below 4mm to 5.8mm, to better match for patients’ anatomies.
Q: What differentiates this disc for surgeons who are looking for an innovative, motion preservation product?
DH: The lower height is really important. Two-thirds of the discs used in our two-level study are the lowest height. We are doing two clinical trials in Europe — a one- and two-level trials. In both cases, we are doing a prospective series of our Simplify Disc and comparing them to previous fusion controls. It's streamlining our ability to enroll in the studies.
One other issue you hear a little more about is nickel allergy. Our device isn't made with nickel. We had a few patients in our clinical trials indicate they had a nickel allergy and couldn't undergo disc replacement with other discs because they include nickel. During our clinical trial, those patients are doing great.
Q: Do you think disc replacements will become more common in the future?
DH: We think the disc replacement market is a really interesting one and more streamlined technologies are coming forward as well as more potential benefits we hope to document. Clearly the imaging is an advantage, and we'll see if the lower height makes a difference clinically.
There was a lot of talk that this was going to be a replacement for fusion and that just isn't going to be the case. Artificial disc replacement has replaced a percentage of fusion procedures, but there have been hurdles. Some early generation technology was difficult to implant. You didn't have reimbursement and there were very skeptical payers. Reimbursement now is much better, the data looks good and payers are now paying for disc replacement.
In that way, the market has continued to expand, and I think that innovative technology that has interesting benefits complements the good work early disc companies did.
As the market reaches an inflection point, spine companies are finding the best way to increase their business is by having a disc as part of the product offering, and I think they are feeling it is more important all the time to have a quality product there. I think some of these spine companies are going to be putting more effort into the motion preservation space, which is a critical part of being able to expand.
Q: Spine surgeries are increasingly moving into the outpatient setting for the appropriate indications. Is this something that could be performed in an ASC?
DH: Half our clinical trial was performed in the ASC setting. The other half was in hospital outpatient. That's a complete change from our previous enrollment, which was from 2005 to 2007 and everyone was hospital inpatient. So over the course of 10 years, we have seen those procedures move into the surgery center. We think a lot about the support for instrumentation and how we can support the ASC setting as a low cost of service.
We started the one-level study in 2016, and we were surprised to find out surgeons were performing the surgeries in an ASC. We had a few calls with payers and asked whether they were encouraging patients to go to a lower cost site of service, and they said absolutely. They tell patients the out-of-pocket costs in the hospital and ASC and give patients a choice. They are actively working to move certain procedures in that direction.
Q: That is really interesting. What is the timeline for follow-up on this study? When will the results be available?
DH: One of the challenges in spinal implants class 3 [is] you have to follow patients for two years after surgery. Already in the one-level study, we are submitting our first module. If things go well, we are looking at 2020 for the one-level and 2021 for the two-level realistically. Now it feels like we can see the end — we have a lot of data now that shows patients are doing well, we are interacting with and starting to submit to the FDA.
We have commercialized with surgeons on a limited/strategic basis in the EU. Our goal there is not a revenue-maximizing strategy; it's working toward keeping the procedure with a specific set of surgeons.