Mark Klausner - Managing Partner, Westwicke Partners Jeff Soinski - CEO John Simpson - Founder and Executive Chairman Jeff Soinski - CEO Matt Ferguson - CFO.

Jason Mills - Canaccord Genuity Chris Cooley - Stephens Steve Lichtman - Oppenheimer.

Good afternoon ladies and gentlemen. My name is Lilliana [ph], and I will be your host operator on this call. After the presentation we will conduct a question-and-answer session. Instructions will be provided at that time. [Operator Instructions] Please note that this call is being recorded today, Wednesday, May 4, 2016.

And will be available one year on the Investor Relations section of Avinger's Web site at investors.avingers.com. I would now like to turn the meeting over to Mark Klausner of Westwicke Partners. Westwood Partners..

Thank you. And thank you all for participating in today's call. Joining us today are Avinger's CEO, Jeff Soinski, Founder and Executive Chairman, Dr. John Simpson, and Chief Financial Officer, Matt Ferguson. Earlier today, Avinger released financial results for the first quarter ended March 31, 2016.

Before we begin, I would like to remind you that management will make statements during this call that include forward-looking statements within the meaning of federal securities laws which were made pursuant to the safe harbor provision s of the Private Securities Litigation Reform Act of 1995.

Any statements contained in this call that are not statements of historical fact should be deemed to be forward-looking statements. All forward-looking statements, including without limitation are examination of historical operating trends and our future financial expectations are based upon our current estimates and various assumptions.

These statements involve material risks and uncertainties that could cause actual results or events to materially differ from those anticipated or implied by these forward-looking statements. Accordingly, you should not place undue reliance on these statements.

For a list and description of the risks and uncertainties associated with our business, please see our filings with the Securities and Exchange Commission.

Avinger disclaims any intention or obligation except as required by law to update or revise any financial projections or forward-looking statements whether because of new information, future events, or otherwise. This conference call contains time-sensitive information and is accurate only as of the live broadcast today, May 4, 2016.

I'd now like to turn the call over to Jeff..

Thanks, Mark. Good afternoon and thank you all for joining us. I'm very pleased with our first quarter results, led by our early success in the U.S. launch of our Pantheris image-guided atherectomy system.

We received 510k clearance on March 1, and by the end of the first quarter had already sold Pantheris into approximately 60% of our lumivascular accounts. This is a good indication of how much enthusiasm there is for Pantheris in the market place, as well as the great work by our sales and training teams preparing the market for launch.

Overall, we're encouraged by the early commercial uptake of Pantheris, and I'll turn the call over to Dr. Simpson shortly to provide some highlights on what he's seen in the field. But first, I'd like to update you on our operational achievements in the quarter. The U.S.

commercial launch of Pantheris in March drove the highest quarterly sales results in Avinger history, with total revenue of $4.5 million in the first quarter. We also significantly expanded our installed base of lumivascular accounts. During the quarter we added 12 new accounts, reaching a total of 107 at the end of the quarter.

We sold five Lightboxes during the quarter, including three [indiscernible] accounts, and two conversions of existing placement to purchase accounts.

This continued strong growth in new accounts speaks to the appeal of our lumivascular platform, and provides further validation that our more flexible capital acquisition model, including our placement to purchase initiative is working.

We continue to evaluate the most effective programs to grow our installed base, and remain comfortable that we'll achieve our goal of approximately 150 lumivascular accounts by the end of the year.

Turning to sales and marketing, we continue to strategically build our field sales force, and ended the quarter with total headcount of 62 sales professionals.

We continue to expect to reach our goal of 70 sales people by the end of 2016, and are encouraged by the high levels of talent, experience, and enthusiasm we're seeing in both our recent hires and in the candidates in our recruiting pipeline. I'd now like to ask Dr.

Simpson to share some of his recent case experiences and feedback from physicians who've used Pantheris. Following Dr. Simpson's remarks, Matt will review our first quarter financial results, and review guidance for 2016. All the [indiscernible] comments on our clinical and product development plans for 2016, and then we'll open the call for questions.

John?.

So, thanks Jeff. Thanks to everyone, I want to add my welcome to everybody, very sincere. I know you all have incredibly busy schedules. So we're thrilled that you're on the call. I want to complement Jeff for summarizing the status of Avinger in four paragraphs, that's a profoundly daunting task.

But I think everything that he's summarized is really to be taken to heart, if you will. And so from what Jeff said, and from what I was saying, I hope it's clear that we understand the magnitude of this opportunity. And we're prepared and working hard to show the interventional world.

And the interventional world is very complicated now, interventional cardiologists, [indiscernible] and surgeons. So we're intent on showing the entire world the advantages associated with the lumivascular treatment.

This treatment, now available in over 100 hospitals nation-wide and it still has these three themes that dominate, and remain very consistent to all of our previous presentations. And the first is the outstanding safety profile.

Overall, it just is so reassuring to the physicians and better outcomes for the patient when they can see what they're doing. They get to see from inside the artery while they're working on it. And of course this leads to the number of second point, which should be great clinical outcomes.

And then number three, not the least of which would be this new definition of the type of and the variability of lesions being cross with the Ocelot, and treated with the Pantheris catheter, we're seeing really a unique distribution, and the composition of plaque.

And it varies dramatically from patient to patient, which I'm sure is no real surprise, particularly not a surprise to the surgeons. But what really happens to the vessel when it's treated with existing technology is now really clear as we image many of these arteries while we're working on them.

And as always happens with new technologies, particularly the ones that I've introduced, and which also helps explain all this grey hair, we see areas for improvement in both Ocelot and Pantheris primarily focused on making both more robust and smaller, as both are being used in increasingly difficult anatomies, and also in smaller vessels.

So while we continue to improve our catheters, we're also designing trials to expand the clinical [indiscernible] the concepts of lumivascular, and keep the physicians focused on the advantages that they can bring to the patients.

So, the first of the trials that we're setting up, the first trial that's really focused on the radiation reduction opportunity, and will be a randomized trial comparing Pantheris and Ocelot, the outcomes to traditional therapies while measuring the radiation exposure to the docs, the patient, and the staff.

Frequently talk about measuring the radiation exposure to the patient. But it's really the physician that sees the majority of the exposure, and that's really where we'll focus a lot of our attention.

Our second clinical trial, if you will, will be a registry to compare the safety and efficacy of Pantheris and Ocelot outcomes to a large existing database of a large healthcare insurance provider by now. With the procedures that are in this trial will be performed actually by the physicians from the provider, from the large insurer, if you will.

So the third will be an independent [indiscernible] adjudicated prospective randomized trial, which is the trial that will allow us to compare the safety and efficacy of the Pantheris and Ocelot to other leading treatments for PAD.

The exact structure of these trials is evolving, but the current proposed enrollment timelines will be presented by Jeff in his closing remarks. As we're making progress in all these areas, it will be shocking to you that I wanted to go faster. Committed to making that happen, and I am very committed to making that happen.

And I will close my remarks by thanking all of the docs and patients who've been involved in our trials, but also in our commercial launch, and all the Avinger employees whose tireless efforts have made this possible. So with this then I'll turn the call over to Matt for the financials..

Thanks John. Total revenue was $4.5 million for the first quarter ended March 31, 2016, that's a 117% increase from the first quarter of 2015, and a 59% increase from the fourth quarter of 2015.

Revenue related to our Lightbox imaging consoles was $1.2 million, a 100% increase compared to the first quarter of last year, and consistent with the fourth quarter. Revenues from disposable devices were $3.3 million, a 125% increase compared to the first quarter of 2015, and a 105% increase from the fourth quarter.

The strong revenues results in the first quarter of 2016 were primarily driven by the U.S. launch of Pantheris in the beginning of March. Gross margin for the first quarter of 2016 was 26%, down from 38% in the comparable quarter of 2015.

The decrease was primarily attributable to costs associated with initial manufacturing of Pantheris and the anticipation of its commercial launch, as well as some increased reserves against inventory and warranty accruals as a result of the modifications to Pantheris that we've made to address the early learnings from the commercial launch.

Operating expenses for the first quarter of 2016 were $16.2 million, compared to $10.2 million in the first quarter of last year. This growth was primarily attributable to expansion of the company's commercial organization and marketing expenses associated with the launch of Pantheris.

We do not expect those marketing launch expenses to continue through the same level through the remainder of the year. And as a result, we expect that the overall operating expenses will also decline slightly in the second quarter relative to Q1.

Loss from operations for the first quarter of 2016 was $15 million, compared to $9.4 million for the first quarter of 2015. Net loss for the first quarter of 2016 was $16.2 million, compared to $10.4 million in the first quarter of 2015.

Adjusted EBITDA, which is a non-GAAP measure, was a loss of $12.7 million for the first quarter of 2016, compared to a $7.9 million loss for the first quarter of the previous year. Turning to our balance sheet, cash and cash equivalents totaled $26.9 million as of March 31, 2016, compared to $43.1 million as of the year-end 2015.

Total debt at quarter end was $30 million. In addition to the cash currently in our balance sheet, we also have immediate access to an additional $10 million through our existing debt facility. And $10 million beyond that will become available based on achievement of $25 million in trailing 12-months' revenues by the end of this year.

Turning now to our financial guidance for 2016, we continue to expect 2016 revenue to be in the range of $25 million to $30 million, representing year-over-year growth ranging from 134% to 180%.

We also continue to expect adjusted EBITDA for 2016 to be a loss of $40 million to $43 million, representing an increased loss of approximately 19% to 28% over 2015, as the company continues to expand its commercial infrastructure related to the launch of Pantheris, and invest in the further development of its lumivascular platform products.

We also continue to expect net loss per share for 2016 to be in the range of $4.35 to $4.55, and that assumes a weighted average share count of 12.8 million shares. At this point, I'd like to turn the call back to Jeff..

Thanks Matt. While our primary focus for this year remains continuing to execute on the successful launch of Pantheris, expanding the base of lumivascular accounts, and driving utilization in existing accounts, as Dr. Simpson discussed, we're also making good progress on the clinical and product development fronts.

For our clinical study focused on the radiation reduction benefits of OCT-guided atherectomy, we expect to finalize the protocol this quarter, and initiate enrollment in the third quarter.

Our second study will be conducted in a large Blue-owned hospital system, and will compare clinical outcomes, quality metrics, and health economic measures associated with the lumivascular treatment of PAD against a matched historical cohort of endovascular treatments.

Enrollment for this study has been approved by the relevant institutional review boards, and is expected to also begin in the third quarter. As Dr. Simpson mentioned, our third study will be a randomized control trial comparing Pantheris safety and efficacy to other leading PAD treatments, and is expected to track longer term outcomes.

We plan to refine the details of this study as we gain more commercial experience with Pantheris, and will likely have the protocol defined and site selected by year-end, with enrollment anticipated to commence early in 2017.

Avinger is committed to real-world long-term comparative data, proving out the clinical efficacy and safety benefits of our lumivascular platform. We're excited about the body of data that will created by these studies, and look forward to sharing more details of the individual studies over the next couple of quarters.

We have a philosophy of continuous product improvement at Avinger. We've already been making some minor product modifications to Pantheris based on our early field experience.

At the same time, we're making substantial progress on extending our lumivascular platform with Pantheris product line extensions that increase the range of anatomies and lesion types we can treat. Pantheris is configured today as best suited to address PAD treatment in the larger vessels above or behind the knee, such as the SFA and popliteal.

We estimate that the market currently available to us represents approximately 50% of the overall PAD market. We have active R&D programs underway to develop a lower-profile device for use in smaller vessels, as well as enhanced cutting mechanisms that will allow us to address most lesions typically encountered in vessels, from the hip to the ankle.

Our goal is to file a 510k for the devices with the enhanced cutting capability in the third quarter of this year, and to have FDA clearance by the end of this year.

We anticipate that we'll be in a position to file a 510k for the lower profile device early in 2017, and expect both of these new products to contribute to incremental revenue growth next year. In summary, we're pleased with our early momentum in 2016, and are excited about our prospects going forward.

With that, we'd like to open the call to your questions..

[Operator Instructions] And our first question comes from the line of Jason Mills with Canaccord Genuity. Your line is now open..

Great, thank you. Jeff, Matt, and John, congrats on a good start to the Pantheris era [ph]..

Thank you, Jason. Appreciate it..

Super. So I wanted to start there with Pantheris. You didn't breakout specifically the Pantheris revenue - catheter revenue in the quarter.

But if we assume that the run rate for Ocelot improved modestly, would it be fair to assume that Pantheris catheter revenue was above $1 million or $1.3 million-$1.4 million? Am I in the ballpark there, just as a start?.

Jason, this is Matt. Yes, I think you're in the right ballpark. We haven't broken out the individual products, but I think if you were to look at the historical trend for our disposable devices, which we have provided in past quarters, that we're very much in that same range for Ocelot sales.

And then the incremental disposable revenue that we generated in Q1 really was attributed to Pantheris. And then, of course, the Lightbox revenue has bounced around a bit from quarter to quarter, but we did provide that number. So hope that that helps..

You broke that out, so that was a known. So that leads to my second question which is, the run rate in just a month, obviously, you only had it for a month, was better than what we had modeled. And you also gave detail, Jeff, that you penetrated 60% of the accounts.

Now, correct my assumption if you might, but I'm assuming that the Lightbox placements are in those facilities that plan to use it -- use Pantheris in addition to Ocelot, so eventually that gets to 100%.

But given that you're in 60% this quarter for just a month, it would imply that if we're calculating the ESP correctly that you're quarterly utilization rate in those 60% of accounts was north of 20 units per quarter.

Was there any stocking or anything that would result in that utilization rate that I mentioned being wrong? And that certainly portends positively as we look at what we had modeled previously for the rest of the year, and obviously makes your guidance look eminently doable.

Could you comment on those numbers, and perhaps just give a qualitative overview of the thoughts for the ramp through the rest of the year. Sorry for that long question [technical difficulty]..

I appreciate the question, Jason. So, really, we're just looking at one month, as you know, with the approval on March 1, of Pantheris revenue. And really what we're seeing in that month are the initial orders of Pantheris. And so it's, I think, too early to project utilization or reorder rates based on a single in-month quarter.

I think our second quarter revenue, I think, you're exactly right, we will now be focused on, of course, getting the initial orders in the remaining accounts, continuing to add new accounts, and very importantly, driving utilization in our existing accounts.

But I wouldn't project too much about utilization rates based on the one month of revenue, and based on the vast majority of those orders being initial orders and accounts. I'll also say though that we were really pleased with how rapidly we were able to penetrate such a large percentage of our accounts.

And I think that does speak to, and we've talked about on past calls, our efforts with [indiscernible] committees, with physician training, with training of our sales force in advance of the actual approval of the commercial or enhanced version of Pantheris, where we were really answering Dr.

Simpson's call, to not squander the opportunity of the early clinical approval in the fourth quarter of last year of the clinical device. So I think it also -- we are, as we said in our press release and also in Matt's comments, we're reaffirming our guidance for the year.

Again, we're at the end of the first quarter or just one month into this launch, and we don't want to get too far ahead of ourselves here. But of course, extremely pleased with how quickly we've come out of the gates, and going everything we possibly can to continue that positive momentum..

That's helpful color, Jeff. I appreciate that. Just, I have several questions, but I'll limit it to one more, and then get back into queue. With respect to penetration of accounts, you had 60% of them, I guess, exiting the quarter.

How does it look for you to penetrate the remainder of the 107 at least, let alone any additional accounts that you add here in the June quarter?.

Yes, I mean, I think it -- certainly given the efforts that had started even prior to the approval of Pantheris and our continued efforts and progress, and mostly the appeal of this lumivascular approach and excitement around Pantheris, as well as the, of course, strong atherectomy reimbursement, and we feel our prospects are very good to continue that penetration..

Great. I'll get back in queue, and let others jump in. Thanks..

And our next question comes from the line of Josh Jennings with Cowen and Company. Your line is now open..

Hi, good evening gentlemen. Thanks a lot, and I'd like to second Jason's congratulations on the momentum and early success with the Pantheris launch..

Thanks [technical difficulty]..

Absolutely. If I could start off with just a question, maybe for Dr. Simpson and Jeff. Dr.

Simpson, you talked about the safety and efficacy of the Pantheris device, and I was just hoping for some incremental color just on how the VISION trial data is being digested, now that you're officially marketing it with the commercial launch here, with the Pantheris?.

So it's continued excitement that is really amazing. Because you know we had no vascular perforations in the VISION trial. And we've had no perforations during the commercial launch. I don't actually have the numbers of or how many case we've done, but it's a large noticeable number.

And if the perforation risk was not really dramatically -- very totally consistent with VISION we'd know about it by now, and it's absolutely consistent with everything we've seen in VISION. There have been no surprises in terms of the function of the devices.

We are seeing the devices used by new doctors, and perhaps they're not quite as gentle with the device maybe as I would want them to be. But I just believe that there's -- everything is totally consistent. And so for sure there have been no surprises along those lines.

And maybe it's a favorable surprise just to know that we've been able to reconfirm everything that we saw in VISION..

Great, and just in terms of how they're perceiving the VISION data, well, in terms of how competitive it is with other datasets that are out there, our understanding is that the VISION trial was one of the more rigorous datasets for 510k approval, with the other devices on the market having -- the clinicians having longer experience with those.

But this dataset resonating with clinicians I guess is the follow-up there?.

Yes, and I think for sure, yes, it does resonate with everybody. Everybody wants a large dataset when in the process of doing those -- what we were alluding to in the call was all the different trials that we're going to do to expand that dataset.

But to say that you can treat patients with the profoundly low risk of dissection, [indiscernible] perforation or any kind of complication is just really -- I don't think anybody now questions the VISION data. I think at one point they might've said, wait a minute, this will be too good to be true. But I think it's not.

And I think also it'll -- this will translate into better long-term outcomes. We [indiscernible] be able to confirm that we can have due procedure with alleged radiations.

I think that the VISION, everything that we have seen so far really is well-aligned with all the VISION data, which I think the world is beginning to accept the VISION data as relevant. Small trial, but relevant data, I think it would be hard to deny that now..

Excellent. And then, Jeff, you talked about the pathway for the below-the-knee device.

Any further color you can give us on just what's going to be required to get that -- the regulatory approval and some of the timelines out in the next year?.

Yes, so Josh, we look at both devices and the enhanced cutting capability, as well as the lower profile as 510k filings. And we do not anticipate that there will be any clinical studies required. And so we're well along in development of both products, very pleased with R&D effort and focus, and we're on track.

I think this is the first time we've provided specific timelines as to when we'll be filing. And of course, we anticipate no surprises in the approval timelines with FDA..

Excellent. Just one last follow-up, just vessel prep, and then followed by [indiscernible] balloon has garnered some momentum here over the last six to 12 months. And understand that longer term, the prospects of Pantheris being a single-device solution for a wide variety of lesion sets is -- again, we understand that.

But just in the interim, would you guys ever consider a distribution partner with a company that has a [indiscernible] they're in international markets as you have [indiscernible] approval or even domestically? Thanks a lot..

Yes, so I think that we do see the drug-eluting balloons being used, they're used for drug delivery, they're not being used for angioplasty effect, which is [indiscernible] eventually use Pantheris. And I think we would be open to all kinds of considerations.

I think overall I personally believe that the majority of the patients could be effectively treated. Surely they do not need additional angioplasty. Whether they need drug or not is -- this would be a part of the study to define that. I think probably more people getting drug than needed.

So, I would really -- my leaning would be toward trying to study that and find out what the real answer is. But overall, if I can create a pretty much a normal artery, then angiographically and by OCT.

The OCT images are really dramatic in terms of how big the [indiscernible] that you've created, [indiscernible] and what the surface is like, it's really -- that part is so special and so unique that it's going to drive adoption, I think, in a big time way. I'd personally think it'll drive us away from drug.

For sure, it's already doing us away from just [indiscernible] angioplasty, I personally believe, and also, eventually away from the drug..

I'd like to build on what Dr. Simpson said around stent usage. One of the things that was so exciting coming out of the VISION data was the very low usage of stents, at around 4% across the study. We continue to see in our early clinical experience very, very minimal stent usage and placement.

A big part of what we're all about with this technology and this lumivascular platform is to provide information for the physician so they can decide what's best for their patient. Now, in some cases they do decide to use DCBs. They are certainly a factor in the market.

But we want to empower them with information, we want to empower them eventually with data to help make those decisions better. Having said that, as you know, there is a large degree of interest in the combination of the significant de-bulking provided by directional atherectomy prior to use of a drug-coated balloon.

I think we are -- will very much benefit from the building body of evidence from other companies, as well as the clinical acceptance of the need for this plaque de-bulking prior to deployment of a drug-coated balloon. So again, I think that works to our benefit..

Great. Thanks for that download..

And our next question comes from the line of Chris Cooley with Stephens. Your line is now open..

Good afternoon everyone. And let me just -- I just need to [indiscernible]. So it's a great first start for Pantheris, you're very proud of the results. If I may -- could you just maybe remind us a little bit about the sale force, you're truly expanding the number of reps there.

Could you give us some color to the types of ads that you're bringing on? And then additionally, along those same lines, how are they allocating their time? I'm just trying to get maybe [indiscernible] outcomes early one with this technology and with the enhancements you've made to the Pantheris device just maybe updating [indiscernible] on the learning curve.

And then I've got one quick follow-up. Thank you..

Yes, so as we continue to build our sales force, as you know, we added five sales professionals this quarter. And we'll continue to build up to that number of 70, and feel like we're very much on track to do that.

We're adding, what we call area sales managers or territory sales managers who are focused on supporting physicians at the individual account level. And their activities and their time is spent really across two areas.

One is driving utilization, supporting physicians in cases, and we've invested quite a bit in training to make sure that they could provide very competent and confident support of physicians. And certainly help drive those early positive clinical outcomes.

But they also are tasked, and Joe Rafferty, our new Vice President of Sales, I think has really added another level of discipline, accountability, and I think healthy process to our company. So that they're focused and tasked with added and prospecting for new lumivascular accounts.

A lot of the emphasis is on targeting the right accounts who have or have the ability to build the PAD volume, but who also understand and buy in to the clinical benefits of our approach. And so, it's hard to quantify how that's split.

I'd say more on driving utilization in early Pantheris case experience, but then, in addition, prospecting for new business and accounts or [indiscernible]. And then sales management certainly helps at the executive level, along with our lumivascular sales managers who are focused more on the capital piece.

The only thing I'll add here, Chris, as you see, we've continued that accelerated pace of adoption of the lumivascular platform. We are of course selling Lightboxes, but we also are executing against our placement to purchase initiative, and driving evaluations. We've introduced now, with the launch of Pantheris, also a rental model.

And that's -- we're starting to get our first experience with that model during this quarter as well. So providing the opportunity to listen to customers to provide a solution that works for them, and most importantly get this empowering and completely differentiated technology into physicians' hands more quickly..

Super. And then just this is a quick follow-up. Very impressed with the three trials that you're getting ready to commence. I think that's tremendous that you're going to have that kind of data, and I think it's going to be very unique within this space. Just curious though, if I can press you a little bit more there.

I realize you've given us a ton already, but help us think maybe about the size of some of these [indiscernible] trials, and maybe when under maybe a best case-type scenarios you could complete enrollment, and possibly start to see some of that data. In particular, I was interested in the [indiscernible] opportunity there starting in early '17.

I think that would be very, very telling data. So any additional color you could provide there would be great..

Yes, so maybe I'll take a couple of the studies and the timing. And then obviously Dr. Simpson can add I think some great perspective. But as it relates to the first study, the radiation reduction study, which will have a number of other acute and secondary endpoints that are tracked, that is an acute study.

So we'll initiate enrollment in the third quarter is what we anticipate. And we anticipate completing enrollment by the end of the fourth quarter. So you should see data coming out from that study relatively soon.

The enrollment period for the health economic study that we're conducting in a [indiscernible] system, again, that will begin enrollment in the third quarter. And that is anticipated to be a one-year enrollment period, with then a two-year follow-up period.

But of course, there will be opportunities for data to be pulled, analyzed, and presented along the way. But just to give you a sense of timing and timetables for those two studies, we have not finalized the protocols and final design for the randomized trial which we'll compare to other atherectomy treatments that you mentioned, Chris.

But I would anticipate generally a one-year enrollment period for a study like that with a minimum one to two year, but probably two-year follow-up with then the ability to pull data at different points along the way. And I don't know if you want to add any perspective to that Dr. Simpson..

Yes, [indiscernible]. I don't think the enrollment will take that long. And I don't think that we would require much beyond a one-year follow-up. I think we'd be -- that would be, if that's required, it would be inconsistent with the existing trials that have been ongoing out there in the trial size.

The trial sizes have raised pretty dramatically from the small files and the 100-patients per-arm to 300-patients per-arm to the maximum. So I don't see the -- it depends on the trial size of course, and how long the enrollment takes, and also the lesion characteristics that are going to be used for the inclusion-exclusion criteria.

I don't feel like that that's going to be a daunting trial. And I think the enthusiasm for enrollment will be high. And it doesn't even have to be an enrolment one-to-one. Maybe there's some bias toward more Pantheris in the atherectomy arm for Pantheris. So I don't -- I feel like you said the right thing because it's very conservative.

That's what you're supposed to say, but I think that's a little bit too conservative..

Understood. And if I could just maybe squeeze one last [indiscernible] and then I'll get back into queue.

When you look at placements [indiscernible] the growth in the install base of the Lightbox units out there [indiscernible] lumivascular platform, it seems, I'm just looking here at the last two quarters as the run rate bias here is towards the rental or the initial placement [indiscernible] time model.

Are there opportunities that you can have on that front to step on the proverbial gas, and further accelerate that install base here in the short run.

Is that effectively becoming the default entry for the new systems?.

Well, we did share the number of accounts that were sold during the quarter as well. And we continue to I think sell a significant number of Lightboxes.

And the idea with the conversion program or the placement-to-purchase program is to eventually convert those to either a sale or a rental, or some other kind of option, including one of our leasing options. So the whole reason for introducing this more flexible model is to accelerate the adoption.

I think the very broad appeal, and as more experience is gained in the market, and with Pantheris, we'll continue to see an acceleration of placements. But we've guided to 150 by the end of the year. We're well on track to achieve that, but I think inherent in that guidance would be an acceleration through the remaining three quarters..

Great. Thanks again and congratulations on the great quarter..

And we have a question from the line of Jason Mills with Canaccord Genuity. Your line is now open..

Thanks for the follow-up, and surprised to get in again, guys, but thank you. Let me follow-up on that last question from Chris.

Jeff, asked in the different way, do you expect the mix to change much relative to what you've seen in the last couple of quarters between the various placement models that you have, sale, purchase-to-placement, rental, et cetera?.

Yes, it's hard to predict with great specificity. But we expect to see a similar kind of ratio as we move forward, especially as more of these placements and evaluations are completed, and become eligible for transactional -- for purchases.

So I would expect kind of the similar kind of ratio, but obviously our goal is to get people started on Pantheris as quickly as possible, because we want more patients to have access to this technology..

Sure, that makes sense. And then Dr. Simpson, thank you for the -- and Jeff, thank you for the details on the studies. In addition to the three studies you've mentioned, Dr.

Simpson, I'm curious just based on your conversations with physicians, whether or not you expect physicians to run their own studies, sponsored studies that we might see at some point over the next couple of years. My guess is you're into some high volume clinics, labs.

And you might have a few folks that have enough volume to want to publish on it at some point.

Just wondering if you have any visibility into that?.

Yes, for sure, that's always the case I would say, Jason. And I think the docs and general enthusiasm for the lumivascular approach is going to drive them to do their own studies. And you may have talked to [indiscernible] are in the process of doing some of that reporting on their own experiences. So we would definitely see that going forward.

I think that it's going to be driven by some of the really -- obviously the truly unique features of this. And there will be some anecdotal reports.

Some unique anatomies that we would not have imagined treating with vein graphs that are a little bit surprising, I suppose, but there are so many opportunities here that it would be always absolutely the case that there will be single-center reports. That would do nothing though to dissuade us, if you will, from doing our own larger trials.

And I think it'll be the merger of all these, the single-center site and then our more expanded trial that will grow this database fairly quickly. I expect this database to develop much more quickly than maybe some of the databases that might have surrounded [indiscernible] pervious devices. So I could not be more excited about it.

I think the single-center contribution will be notable..

That's helpful. And then last quarter for me, and I'll let others jump in again if they have any other questions. But been talking to some physicians at Sharing Cross and a few other meetings this spring, what was striking to me, to us, was the utilization of Pantheris in early -- in very challenging lesion sets.

I saw a few pictures where you -- Pantheris was used in quite long lesions, heavily calcified lesions. Frankly, probably -- and not considered your chip shots at all, and some CTO as well. Obviously utilization of Ocelot was employed there.

So could you talk about what some of those cases, and whether you've been surprised by the utilization early days here with Pantheris in those challenging lesion sets, and what they maybe portends for its use going forward?.

Well, I do believe that what almost always happens is that the doctor on their first case will do it just exactly what you say. And on the second case, for sure, it'll be nothing like what you say. And so there's very little -- whatever coaching and advise that we give, they radically depart from that from really, really early going.

The part that I do find really quite remarkable is how nicely the device is working in some really complex anatomy. Maybe the really heavily calcified arteries are still a bit of a stretch for us. But we definitely will be, and that's a part of our mission, to make a more aggressive cutter, if you will. A more efficient cutter for dealing with.

So feel like that everything that I see is very reassuring. I feel like also that the exciting part is that any of the improvements are always within the achievable domain of our engineering base. So they're really, really good at dealing with all these issues.

And I feel like that early-going, the long lesions, which kind of surprised us, and I know a couple of lesions that you must've been looking at. But obviously, when you think about a long lesion, frequently the long lesion has two really tight spots, the top and the bottom.

So if the treat the two really, the proximal and distal caps, if you treat them with Pantheris, in a very predictable way the rest of the lesion becomes a little bit less important.

But it tells you how much we are evolving our database, and how much we're learning to better understand the distribution of the plaque, what it does inside the artery, and how best to treat it. And these are all things that we never had -- Jason, as you already know, we've never had that available to us before.

So it's already influencing the outcomes, it's also influencing their position adoption. They're willing to try it in places that I probably would think you got to be crazy. And it's actually working out pretty well, I mean in those cases..

Thank you very much..

And our next question comes from the line of Steve Lichtman with Oppenheimer and Company. Your line is now open..

Thank you, hi guys.

I was wondering, in this first quick conversion of the 60% of lumivascular accounts, what you're seeing from a training perspective, how that's going relative to expectations? Are you seeing a quicker ramp than expected, any commentary around the initial training?.

Yes, so as you know, we started training docs in the latter part of in the first quarter. And at the end of the first quarter, I think we gave numbers on our call on March 1, as to where we were. But we were at about 131 -- a little over 130 docs trained. As of today, we're well over 170.

And we have another training tomorrow, which will put us well over 180 docs. So we continue to train. We had eight training sessions in seven different locations in the first quarter, and another four so far in the second quarter this year. So I think it does two things.

First of all, where it speaks to the appeal and effectiveness of the training, but especially our lumivascular platform, but also, again, supports the ramp here of Pantheris as we move forward..

Great. Thanks Jeff. And then just secondly on the radiation study, certainly the lower radiation benefits [indiscernible] something we've talked about before. Just wondering what you think the -- and what you'll be able to do with this data.

Certainly, the physicians I would assume already know the benefits as this could be helpful for them as they approach hospitals or is it potentially from a economic/payer perspective, just curious on the potential benefits of that trial?.

Yes, I mean, I think that everyone knows. And we're seeing, and we're seeing that it's not only in single-site studies that we've, I think, shared that data before, but also in our clinical practices.

And I think there continues to be a very high level of importance being placed on reducing radiation both from the physician standpoint, but as well as the institutional standpoint, because, as you mentioned, not only are there negative health effects, there's also certainly a real cost as physicians have to sit out for up to two weeks at a time because their radiation levels get too high.

So we think by quantifying that reduction, we certainly moved the ball forward. We're also going to be tracking secondary endpoints consistent with other endovascular trials, like luminal gain, and adjunctive therapy use, and building more of that dataset. Again, as Dr.

Simpson has mentioned, we continue to be thrilled with the extremely safe profile of this device, and the lack of perforations, an clinically significant dissections. And so, as we move forward, we're excited to continue to build that data as well in a controlled setting.

And then finally, there will be other endpoints such as exposure to contrast media for patients, which as a very real cost and health risk to patients. So there's going to be a lot of data coming out of this study, beyond just radiation reduction and we'll share more details around that once we initiate enrollment.

But I think a rich dataset that goes beyond just radiation reduction. I don't know if you want to add anything..

Great..

As somebody who had to go to the sidelines once because my badge was over-radiated. I'd have to say it's not very reassuring either that you have to go to sidelines, and because the radiation effects do not go away just because you're on the sidelines. So I believe that it would not have to be pairs.

It will not have to be providers, hospital, [indiscernible]. The docs will gravitate toward this because they don't want it. They understand the issues. They don't want the radiation, I'm saying..

All right. Certainly makes sense. Thanks Dr. Simpson, thanks Jeff..

Thank you, Steve..

Ladies and gentlemen, that concludes our question-and-answer session. I would now like to turn the call back over the Jeff Soinski for any closing remarks..

I'd like to thank you again for joining our call. We sincerely appreciate your interest in our company, and what we're trying to do here, and look forward to updating you on our continued progress. Thank you..

Ladies and gentlemen, thank you for your participation in today's conference. This does conclude today's program. You may now disconnect. Everyone have a great day..