Sujith Shetty is the vice president of Clinical Affairs at Vascular Dynamics. He recently spoke to CTA to discuss the new medical device his company is developing to treat high blood pressure.
Clinical Trials Arena: The device Vascular Dynamics is developing is very novel. Can you tell us more about it?
Dr. Sujith Shetty: We have a nitinol implant that is placed in the carotid sinus, which is a passive implant that essentially changes the shape of the artery and helps amplify the signal the baroreceptors send to the brain. This increased signal from the baroreceptors induces the brain to reduce the sympathetic tone which will help reduce the blood pressure.
CTA: Is this type of device the first of its kind?
SS: Our company started in 2011 and our first-in-human case occurred in 2013 since it took us some time to test the device and make sure it got regulatory approval. Now we're in the midst of two studies, one in the U.S. and one in the EU, which are our first-in-human studies and we are starting new studies next year which will include randomized placebo-controlled studies. The first question you asked, is it a new kind of device? Yes, it's a novel device. No one has tried to change the shape of an artery to influence a baroreceptor. There is a surgically implanted device that uses electrical stimulation, but to actually use a passive device like we have, no one's ever done that. We're also using standard endovascular procedures to implant the device, which makes it less invasive than a surgical procedure.
CTA: What have been the challenges in developing this kind of device? And also, what have been the initial results?
SS: The challenges? Well, it's a novel device. We worked pretty quickly and hard on making sure we did all the proper testing. We participated in a pilot programme with the FDA to run first-in-man studies in the US. It was called the 'Investigational Device Exemptions (IDEs) for Early Feasibility Medical Device Clinical Studies, Including Certain First in Human (FIH) Studies,' which is actually a guidance document that people can go into, but at the time we joined, out of many applications, the FDA picked nine companies to participate in the pilot programme. So we worked with the FDA for a year to get our first IDE open and the first-in-man case, for a class III implant, actually occurred in the U.S. first and not in other countries, which is very novel also.
To date, we have treated 25 patients, and we've seen very promising results and have a good safety record. A lot of patients have seen a substantial and sustained drop in blood pressure and feel the consequential beneficial effects. So these are good results for a first-in-man trial and now we're moving on to the next phase.
CTA: You mentioned patient recruitment and alluded to how difficult that was in the US. How have you been able to find participants for your studies?
SS: Well, data. Data is king. At the end of the day, for every patient we treat, we let the physicians know how the device has been working and how well it does. In the U.S., we tried implementing direct-to-patient marketing, which we outsourced to any outside company and that unfortunately did not work well. When it comes to any first-in-human situation, patient recruitment is all based off your last patient. If your patients are doing well, it's easier to enrol more patients. In the first year, we were struggling to enrol five, six patients. This past year, however, we've enrolled close to 18 patients. That trend continues to grow as we get more data. Now we're able to share it with the physicians who can tell their patients, 'this is what we've seen so far. Now that doesn't mean you're going to see the same results, but so far it looks pretty good.' Also, the more patients we treat the more safety information we have, and sharing that with physicians is always helpful.
CTA: Since you're dealing with a relatively small pool of patients, do you ever encounter issues retaining them?
SS: Actually not really. Retention of these patients tends to be a little bit easier. Retaining patients is more of a problem when your disease state is less severe. We're treating patients whose conditions are extremely severe – these are patients that have a blood pressure of 160, even though they're on three medications. So they understand that their disease is serious, and so are happy to continue throughout the study. In my career in clinical research, I've seen this in every type of study like this. When it comes to the more severe patient sets, retention is not the issue. The issue is finding the patients.
CTA: Moving forward, what are the next steps in your study?
SS: Right now, we're doing single arm feasibility studies where we assess the safety of the device. Safety is the primary endpoints for our current studies and we obviously also collect efficacy data as a secondary endpoint. The next stage will be to really understand the efficacy of the device in a randomised setting. So we'll randomize through a control/placebo arm and then really take a look at the efficacy of our device. To that end, we're going to kick off a couple of studies that are EU and U.S. based. In a nutshell, it's all about treating a patient set that's randomised to objectively evaluate efficacy and long term durability.