Good day, ladies and gentlemen, and welcome to the Quanterix Corporation Fourth Quarter 2018 Earnings Conference Call. [Operator Instructions] As a reminder, this call is being recorded. I would now like to turn the call over to Mr. Joe Driscoll, Chief Financial Officer. Please go ahead.

Good afternoon. Before we begin, I would like to remind you that today's call will contain forward-looking statements that are based on management's beliefs and assumptions and on information available as of the date of this call. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements. Forward-looking statements involve known and unknown risks, uncertainties, assumptions and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. The risks and uncertainties that we face are described in our most recent filings with the Securities and Exchange Commission. This call will also include certain financial measures that were not prepared in accordance with US GAAP. The information required by the SEC pursuant to Regulation G including reconciliation of the non-GAAP financial measures to the most directly comparable GAAP financial measures can be found in our earnings release issued previously today which is on our website. With that, I will turn the call over to Kevin Hrusovsky, our CEO, President and Chairman.

Thanks, Joe, really appreciate. We really feel good about the fourth quarter of 2018 and also the overall progress made throughout the year. In the same framework that we've used in the past, I'm going to go through a series of slides that are online and on our website. I'm going to start with the agenda where I'm going to talk through the Q4 results and the 2018 highlights, but also going to lay out the 2019 goals and priorities. And then finally, we've made so much progress in the last few months in the area of neurology and the momentum is just continuing to build. I would like to take a few moments to give you some updates that I think are fairly material. Joe will then provide some commentary around the financial reports and then we will go into Q&A. So starting with a slide that basically says, we've defined a technology that's got exquisite sensitivity on measuring protein biomarkers and blood and that sensitivity is approximately 1000 fold greater than the traditional ELISA technology that already was more sensitive than many other technologies. We've been around really since around 2013 with the technology being launched. And you can see that back about four years ago, we decided to go after research first where there's no regulatory reimbursement risk. And we really went from no revenue to 38 million this past year. So that's a very rapid ramp. And about 40% of that is consumables, which is also a very high level of visibility with those types of businesses, which is -- also generates most of our margins as well. So we're pretty excited about just the ramp that we're having at the consumables of this business, but longer term, we are going to go back into diagnostics.…

Thanks, Kevin. I'm going to provide some additional financial details now. As Kevin noted, revenue in Q4 of 2018 was 10.9 million, compared to 6.6 million in Q4 2017, which represents 65% revenue growth. There was no collaboration revenue in Q4 ‘18. Year to date, total revenues are 37.6 million, a 65% increase over the 22.9 million for fiscal 2017. Adjusting for a one time revenue item in Q3 related to the termination of the BM-X agreement, year to date growth was 60%. Gross margin percentage in Q4 was very strong at 48.2%. Prior year Q4 was 43.7%. The 450 basis point increase over prior year was due to a positive mix of consumables revenue, which had 67% growth in Q4 plus the leverage we are generating by the total company's revenue growth. For full year 2018, gross margin percentage was 47.8% versus prior year 43.7%. Excluding the impact of the one-time item in Q3, adjusted gross margin was 46.3% for full year 2018. We believe we have a significant opportunity for gross margin expansion in the future, as we scale our overall business, reduce product costs and continue to drive the mix to more consumables revenue. Operating expenses totaled 14.2 million in Q4 2018, versus 10 million in Q4 2017. We are attempting to accelerate the growth trajectory of the business by making significant investments in the commercial team and the infrastructure required to support our growth. The main drivers of the Q4 2018 increase include increased headcount in sales and marketing plus external strategic marketing investments. 2018 hires of new senior management personnel, payroll and other costs related to the Aushon transaction, non-cash rent expense related to our new headquarters and public company costs, also stock comp expense which is a non-cash expense, was 1.4 million in Q4 2018 versus 800,000 in Q4 2017 due to new grants made in 2018. We will look to continue to add to our commercial organization and other key areas of the business in 2019, including resources to support the development of a diagnostic strategy. Therefore, on a quarterly basis, we expect operating expenses to increase from the current baseline level of 14.2 million. The balance sheet is in good shape as of 12/31/18 with approximately 45 million in cash. This gives us the financial resources to accelerate the growth in the business as well as look at potential acquisitions and the diagnostics development. There were 22.4 million common shares outstanding as of year-end. For 2019 earnings per share, we expect weighted average shares outstanding to be in the range of 23 million. I will now turn it back over to Kevin.

Thanks very much, Joe. Basically, we have a market that we are using some major disruption to get to find and that market we think is somewhat category defining with our unrivaled sensitivity. And so the pace of us continuing to advance our sensitivity we think is important now that we see a real market for additional sensitivity and we are best in class and we want to keep investing to stay best in class on the sensitivity front. We also have had a methodical way of going at this market, starting with research and then evolving into diagnostics as a secondary opportunity, which is where the size of the market opportunity we think could be significantly larger in diagnostics versus research, but it's a little bit riskier, and so we're being much more careful in the way we enter it. Once you find the market which we've done, it's been about the execution. I think that's what is -- has a lot of investors interested in us is that we've got a very disruptive aspirational opportunity for significant value creation, some serious promises coming out via the publications, but we're still executing in the research sector flawlessly so far. And that's our key is to continue to drive the install base, with the consumables going across it. And when we do that, it's actually creating publications and those publications then further fuel the longer term diagnostic opportunity. And so you can see, we've got a built in engine that we're trying to utilize research to actually further enhance our opportunities in diagnostics. And so it starts with validation. And we now have 19 of the top 20 pharmaceuticals using our technology. It's one of the fastest adoption cycles and I've been running these businesses for 25 years in life…

[Operator Instructions] Our first question is from the line of Sung Ji Nam with BTIG.

Congratulations on the quarter and for the year as well. I was wondering for the SP-X, sorry if I don't know this, but is it fully automated and or does -- is it like an SR-X where it will require sample test module as well. Just trying to get a sense of that and also if you might be able to comment on the list price for that as well as what's the potential consumable flowthrough, whether that could be closer to the SR-X model?

Yeah, great question, Sung Ji. And basically, let me start with the consumable side of this. We expect that we're going to maintain this one-third and 75,000 is roughly the list price that we're targeting here. And roughly one third of that is what we feel we are going to be able to drive. The first part of the question was on automation and on automation, there's two things that we've been describing for the marketplace. When we say automation, we actually mean that the SR-X is automated because you can do most of the steps. But then we have this thing called integrated automation, which was what you were asking. And that's when sample prep like on the HD-1 is also integrated. The SP-X is just like the SR-X. It's automated, but not integrated automation. So we have what we would call the different steps for preparing a sample automated, but it's not integrated into this instrument. So for the moment, it's automated, but not integrated automation. And we actually have found a lot of customers that actually prefer not having the integrated automation because they have a lot of sample prep technologies already installed like the T cans [ph] and the Hamiltons and they want to utilize that installed base technology. So we think it's actually good to start this way. Someday though, we could end up with a fully integrated automation for the SP-X, particularly for utilizing it in the area of diagnostics where many times you want that complete, will call bleed the read, the blood sample going in and the actual results coming out.

Great, thank you. That's very helpful. And then for the HD-X platform, which you're targeting launch later this year, was curious to what level of capability that will have and also we're starting to look at kind of I -- I'm not sure if I'm looking at this correctly, but some sort of a product line bifurcation here potentially with the ST-X and also with the SP-X, was curious as to what the product positioning might be or if that’s not how we should think about that?

Yeah. So, HD-X has a couple of dimensions to it. First, I would say, we're looking at more like a Q4. But before the end of the year, we'd like to get this thing launched and we've got a lot of prototyping going on right now and testing going on and it's looking really encouraging. And anyone who buys an HD-1 in the first half or third quarter of this year, we're going to really provide them some incentives. So we don't want to, in any way, impair our HD-1 sales. We want to make sure that customers can get in right away with the HD-1s, which by the way, we've made major advances on that technology over the last 24 months as well. But the HD-X in general, we believe is going to provide temperature control, which today when people run the HD-1, we tell them to manage their laboratory to a certain temperature. So they got to really condition the error in the laboratory where this will be self contained conditioning, so that you can actually run with a lot more precision without having to condition the actual total laboratory. We also will increase with magnetic, the bead loading, which will provide the ability for getting better economics as well as a little bit better sensitivity and we think that those things will be pretty important advances on the HD-X and we also feel that the HD-X is going to be the workhorse with the HD-1s for many years to come. So we think it's -- there's a lot of interest in fully automated technology and so we will continue to evolve this technology with those investments and it will do 6 plex. We do have also on the HD-1, I'm sorry the SR-X, we were able to…

And then just lastly, maybe one for Kevin in terms of your gross margin targets for next year, was curious as to how much of that do you expect to come from the product mix to a volume versus manufacturing efficiencies and other production – reduction in production costs. Thank you.

Yeah. And Joe might want to comment after me, but it seems that we've got the potential here for both of those -- the mix because of consumables as well as the overall build out of just leveraging our fixed costs, particularly in consumables where we have a real -- we produce them ourselves in our facilities, and we have a lot of leverage there. So I think we got an opportunity for both of those categories to be productive. I think we said 300 basis points. Joe, I don't know what you would say.

Yeah. I'd say it'd be about half and half. That would be the genesis of the increase.

Thank you. Our next question is from Tycho Peterson with JP Morgan.

This is Julia on for Tycho today. So first off on instrument, you're expecting 25% growth this year. Just wondering how much of SP-X contribution is embedded in there and to the extent possible, could you give any color on sort of the preliminary order funnel, if you will, or customer interest in the pipeline?

Yeah. So we don't guide at a granular level instrument growth rates and we don't even guide at a macro level our overall revenue. We have said over the last 24 months, though, that we think we can maintain a 40% growth overall, that's not guidance and it’s aspirationally what we feel we can still achieve with this disruption that we're managing. We haven't again provided any granularity to how instruments might play out inside of that. We have seen a major upturn in instrument growth in the second half of 2018, however, which does bode well for helping us pull through consumables and it also is a great leading indicator that the products that we're designing and launching are getting good adoption and interest by our customers to see that kind of pickup. We would believe that SP-X, last year when we launched the SR-X, we felt we could get 40 units out there throughout the year and I think we ended up beating that for about 50% last year, getting I think more like maybe roughly a 50% uplift on what we originally set out to. I think that we're starting out, launching this a little bit later in the year, but I'd be happy if we could get 10 instruments a quarter type of SP-X volume starting in the second half of the year, maybe for sure in fourth quarter. But again, it's – you just never know when you launch new products, how long it takes. That's why we think it would only potentially trip people up if we guided at this point.

And then in terms of the mix of capital sale versus reagent rental, just curious if there has been any sort of changing attempt there or do you expect to see any change in the mix going forward?

Well, it is interesting. We've had a lot of investors as well as analysts say, geez, whatever you do stay away from the reagent rental. It just complicates everyone's worlds. And interestingly, so far, we haven't had the user reagent rental at all. We're hopeful that we can kind of continue to sell our instruments and make gross margin on them, while then later on also selling the consumables across it. That's our goal. And that's -- we've had a good track record over the last 15 years of -- in our management team and we have 65 people kind of in the company from the previous companies that are pretty experienced at doing that. So our hope would be that we can continue doing it. I would say interestingly though, that the economics for the SP-X are somewhat off the charts compared to anything I've seen in a while. It's a much lower cost instrument than what most of the bead based technologies are. So we're able to get to a much lower COGS on that SP-X and so if you ever, we're going to have a reagent rental opportunity, you probably, I think I would probably know of some competitors and that would aggressively start to use the reagent rental to expand penetration very rapidly, but then they could get themselves caught later on in that and so we're going to try to get good momentum without using in a significant way the reagent rental and hopeful that that's going to deliver and we have some couple of test beds by the way, we're actually seeing consumption levels as much as five to six times the COGS annually on the SP-X test beds. So when people get going on this type of test bed technology, we can actually see really interesting economics and again the gross margins there, we believe are more at the 80% level. So it starts to redefine the possibilities of taking our disruption into new economic models. We've been able to be very successful thus far with our technologies and delivering this kind of growth, even though our prices are probably at a higher than, let's say, a Luminex or an MSP in many cases, our pricing has actually been higher, but yet, we've been able to command this installed base because of the differentiation we're bringing something to the market that no one else can bring. So despite the fact that we were higher priced, we've been able to command that growth trajectory. What's also exciting is as we move into multiplex, we're changing the economics so that we're going to now become more competitive with the competition while still delivering the disruption so that's why multiplexing on the SP-X, couple them with a lower instrument cost starts to change the possibilities of the economics of what we're trying to do with the disruption. So pretty excited about the SP-X.

And maybe if I can just squeeze in one last question, regarding gross margin on the service side, could you give us an update on the current capacity utilization of your in-house CLIA lab and like, how do you expect gross margin on the service side to ramp going forward and how does that compare to the expected margin expansion on the product side?

Yeah. It’s interesting. I know you're asking the question for Tycho too, so I wanted to -- one of the things Tycho, Tycho can see a lot of the aspirational opportunity we have in our business and many of the reports he has seen that our service business is very different than what people traditionally think about. This is a almost a strategic Trojan horse for selling instruments later on and then selling consumables on top of instruments. Initially, it was a promotion, it was an expense side. And when we got started, and then we started saying, let's start charging for these trials. And we started to drive gross margins that I think are north of 50%, 60%, maybe, as high as 65% in our services business. And so it's been exciting to see the Trojan horse of every third trial we run translate into signing an instrument to the people that started to run the trial and paid for it. And then later on, they buy consumables on that instrument. So it's kind of an engine for us. But what's really more strategic is the fact that we're now running trials for drugs where those biomarkers that we're running can become complimentary or they can become companion diagnostics. So it's actually like a Greenfield opportunity to actually start looking at relationships with pharma that could lead to diagnostic opportunities and help us start to move into that landscape, now that we have a CLIA lab of our own. So again, there are so many levels of strategy going on in that services that we can talk about, like the utilization levels. But I would encourage all the analysts to continue thinking about the strategic dimensions of what we're doing there. And don't get just wrapped up in a traditional service model and think that this isn't something that is that productive because it's very productive. Now, with that said, we can expand our capacity at any moment by just adding headcount. And we're moving into a new building in the middle of this year, that's going to house both Aushon’s original building of people that we now have a lot of the Quanterix personnel in there. And then our original Quanterix building which we've now moved a lot of the Aushon people into for our integration efforts. So we now today have two different buildings that we're going to be consolidating everything into one and our accelerator lab has got plenty of, what I'll call, fixed cost scaling opportunity in there. So I think we're going to be less than 50% utilized from a, what I'll call, the fixed cost dimensions of the operation, which would be the buildings, the facilities, but we can simply by adding people and adding instruments, we can scale that capacity. So it's a very efficient scaling. It's not major capital investment steps. These are pretty much variable steps. So I actually don't think it's going to be too burdensome for expansion.

Thank you. Our next question is from Puneet Souda with SVB Leerink.

Kevin, great, congrats on the quarter and congrats on completing the first year as a public company. So my first question is around what you are calling about a 40% long term growth, how should we look at that for 2019 and just I'm trying to understand in terms of what consensus modeling you're ahead of that, maybe close to about 3 million or so ahead of that, given the growth you're seeing here in instruments in the fourth quarter, SP-X adding on top of that, and HD-X coming in the year, shouldn’t we assume a bit more acceleration from the long term guide and versus in 2019?

Puneet, you and I go back and forth on this all the time. I'll say a few things here. First, I would say that the way to look at our 2018 revenue performance is 36 million, meaning that we had some one time stuff that went on there around the collaboration revenue and all that. So I think our run rate is running around 36% and what I've been trying is to inform everyone on is that we've got so much disruption and possibilities of significant aspirational value creation that the last thing you want to do is trip up over any models, our short term execution, even though I think you've watched, we've been executing with a lot of visibility into what we're doing with a lot of track record. So I personally think that there's a room for the models to say whatever they need to say. But I would not go beyond the 40%, if I were an analyst, just because there's no need for that, we got plenty of momentum, we believe to be able to bring visibility and bring some level of performance, but hey, we got to remember, this is a disruptive company in any moment. You could end up with something, it gets tripped up. And so I want to make sure everyone understands, we don't want to compromise the possibilities of the future value creation by having a real short term execution of me -- having to push more revenue out. So you're right, could we beat. I don't know we've beat every quarter, I guess if you look at the way the models have been laid out, but I would be more wrapped up in what the possibilities are for, going after an Alzheimer blood tests, or going after the possibility of an MS diagnostic ultimately, and looking at the neuro-disruption that we are beginning to impair or beginning to create and impairing some of the traditional ways of doing business and try not to get too wrapped up and pushing us, I mean, 40% growth is going to be very exciting for a lot of people because our base continues to get bigger. So, we've now said 40% since we were one third our size and so we're continuing to say we still believe we can achieve that and I think it's a good place to kind of think about our future ambitions around growth

And let me ask on oncology and cardiology, you grew quite strongly there. Just give us the, what was the driver behind that. And if you could elaborate on overall, pick up there. More importantly, SP-X, the traditional similar instruments have been designed around sensitivity versus you're getting a lot of sample already in oncology and cardiology. So I'm just trying to parse out what's driving the growth there, SP-X hasn't launched, I mean, SP-X is going to be more of a 2019 story. So just trying to understand what's driving the growth for oncology and cardiology.

One thing that was pretty exciting is once -- we got one of the best sales groups as you know, [indiscernible] heads this thing up, he’s a post-doc from Harvard Medical School and we got a lot of, what will call, application sciences, some of the best in the world. These are a -- a lot of them PhD, supporting our field. We got a very hungry group and then we got investors that look at their pipelines of getting drugs approved that the pharma biotechs and they say to us, these drugs, if you can do something to increase the probability, which we know that using biomarkers can increase the probability of a drug getting approved from phase 1 to phase 3 by 300%. So we have a very strong commercial engine. And so when we bought Aushon, there was already the basis historically of what I'll call some oncology assets, because they were multiplexing. And so our team did do pretty well in placing some traditional Aushon technologies in 2018 and so we did create some oncology movement, but that wasn't what I would consider to be the kind of movement that we really are going for. We have to kind of restructure and launch an instrument that we know has all the scalability and all of the dimensions of longer term financial performance to really get the results that we are used to getting. And that's what the SP-X is, we've taken it and we've [indiscernible] it. We've got greater sensitivity, which we think is a differentiator that's important to have. The old Aushon really didn't have a lot of differentiation from MSP and Luminex. Sensitivity brings great differentiation there. We also work to automate, not integrated automation, but the automation of some of that liquid handling…

Okay. And just if I could squeeze another one on commercial organization, where do we stand now currently in terms of the salesforce, if you could give us a sense there and overall commercial organization. And clearly, you're spending into 2019 OpEx is going up, just to help us give us a sense of overall commercial organization. Where would you like that to be at a steady state?

Absolutely, Puneet. In general, we keep trying to increase our installed base or our number of sales of what I call card carrying, number carrying sales people by about 25% to 30% each year. And I think we're probably up around 15 sales people, 16. But then we have all these other PhDs and field application personnel in product management that support them. So it's probably more like three times that when you end up adding up all those headcount and what we would like to do is continue to expand that by about 25%, 30% and then drive through that revenue growth that’s greater than that. Right. So you'll have some productivity gains in your commercial investments. Now, I would say that we've got some one-time things going on in 2019 that again, if I'm an investor, I'm excited about the fact that we got our all of our IVD rights back for diagnostics, whether that be laboratory developed point of care or IVD centralized or decentralized, we get those rights back. And so we are investing in bringing in Jackson Streeter, bringing in Mary Ellen, some of the key industry leaders in diagnostics to help us sort out and build strategic pathways. We're not exactly sure yet how we're going to go at that, we've laid out a goal that we would like to at least form one LDT relationship in 2019, and we have a lot of interest already from those reference labs and we got great collaborative meetings, but we will have some OpEx, I believe, in 2019 to support that diagnostic build out and the thinking that we're putting into building the right roadmap for the future.

Our next question is from Doug Schenkel with Cowen.

Hey, guys. Could you elaborate a bit more on some of your recent leadership hires, you just touched on it briefly there, but I'm particularly curious how the addition of Dr. Streeter furthers your aspiration in clinical diagnostics?

Yeah, it's -- Jackson's here. And I told him today, I didn't want him like spend too much time talking because we're still trying to sort of lay this out. He's running corporate development for us. So, there's what we would call as pathways between research and diagnostics, particularly in the area of CROs. We have a whole lot of these drug trials running and many of them can be used to help support disease progress validation markers with the FDA, so if you can get an approved drug that can modify the disease by the way, there's none for Alzheimer's right now. They have a lot of them of them for MS, but if you can get an approved drug that can modify the disease and then you can look at retrospective samples and how your biomarker got moved by that disease modification of that approved drug, it can actually lead to you getting a clinically validated biomarker for drug approvals and for disease progression and that's the pathways that Jackson himself did when he was at Banyan, they got UCH-L1 and GFAP, two biomarkers that they did a rule out on the CAT scan that if you could see levels of these markers in blood, you wouldn't benefit from having a CAT scan. So it was a rule out. And in the area of MS, and many of these diseases, you got all these drugs today that might take 2.5 years using MRI, which is much more expensive. And I think on average, MS patients are doing 2.5 MRIs per year to just try to monitor their disease progression, it's the only approved endpoint today but we know brain atrophy could take 2.5 years before MS can bring that result to an MRI where in blood, many of…

Maybe just one quick follow-up, you held the first Powering Precision Health European Summit in December. Given this is the first time you've done something like this in Europe, I’m just curious to hear if you could give us a flavor of the customer response and would you typically expect an event like this to impact sales or accelerate adoption right after the event?

And what I would like to say here is that, let me say first, Doug, that the Powering Precision Health Summit is independent from Quanterix. That is a nonprofit that I found that independent from Quanterix, but it's got a greater purpose of going after disease modifying capabilities for cancer and for neuro-degeneration, those two broad categories and it's looking at biomarkers, whether they be from Quanterix or be from other companies as a vehicle for the revolutionizing way of seeing these diseases earlier and then later stage getting treatments for those diseases and ultimately, can we look at biomarkers to prevent the disease through our annual physicals, knowing really early on that the way we're conducting our life and the environmental factors, the way we [indiscernible], the way we growth hormones, or the way we get subjected to concussions and things of that nature, are those environmental factors triggering disease that you can actually prevent the disease cascade by looking at biomarkers. So I want you to understand that's independent from Quanterix. But Quanterix did participate. And they did a really nice job and they found a lot of customers very excited about biomarkers and you can find on the Quanterix website of a video that gives you direct feedback from many of those researchers that attended and I would say neuro-filament light was showcased there by some of the leading neurologists in the world and they talked about what they consider to be real significant disruption and neuro-filament light has been around for a while. It's a -- it can be tested in cerebral spinal fluid, it's been something that's been -- the key here is the ability to see it non-invasively in blood. That's leading to a lot of new cohort studies because patients don't mind giving…

Our next question is from Mark Massaro with Canaccord Genuity.

Hey guys. Thanks and congrats on the solid Q4. I guess just to maybe bridge Doug's question. One of the highlights that I thought out of PPH was the presentation from [indiscernible] and he said that he began offering blood based NFL to some of his patients with informed consent. So I guess I'd be curious to hear your thoughts, Kevin, on how quickly other physicians and researchers may begin to offer blood NFL to patients and then more broadly clinically?

Yeah, so our position here is that the test should only be being used for research use only. That's the research sector that we're selling this instrument into. But there are like, you say, a lot of trials that they do get patient consent, and they are appropriately running those regulatory trials. And there's more and more of that going on. And we have a lot of patients coming to us asking, not just in neurology, but also in cancer. You might remember the kind of game changing PSA publication that came out five years ago, where we can see PSA at [indiscernible] and that could be a Johns Hopkins and NYU and show that that can be a major for, especially people with radical prostatectomies, it can be an incredibly important biomarker to determine whether the prostate is regrowing or not. And CRO is what you see in today's technologies. But when you take all those CROs, they showed that you can stratify based on our sensitivity and see different disease progression markers. And so not just in neurology, but in cancer applications coming to us and we do not today -- we cannot, we don't have any approvals to be doing that kind of testing. And so laboratory developed tests would be the first possibility we would see in house. Certainly Quest and LabCorp and [indiscernible] they all have our technologies and they all are incredibly great collaborators that have tremendous hope for what we're doing. And we see them to be really well statured around regulatory and reimbursement. And so we're going to be working those relationships in a more formal way with those types of companies in 2019. We ourselves are not suggesting that we will be running any kind of LDT tests in house, but we will continue to run CRO tests in house and that's the kind of worked out of studying that we're doing. I would call your attention Mark to slide 16, where we show the NFL publications taken off. There was a publication that just aired I think yesterday from the doctor that you mentioned. And I just showed the quote from their abstract that says abstract neurology 2019 journal, blood NFL levels are associated with clinical and MRI related measures of disease activity and neural accidental damage and have prognostic value. Our results support the utility of blood NFL as an easily accessible biomarker of disease evolution and treatment response. And then the editorial had said neuro-filament light chain, an important step toward a disease biomarkers in multiple sclerosis. So, those are the publications we have on our website on the Quanterix website where you can read from these third parties and those publications and it would suggest that we get continued momentum towards achieving the ability to see the disease progression, but again there's nothing that's been approved yet and that approval process is necessary before it would be something that we would condone.

Understood. And then I also wanted to ask, the number of publications using your technology has doubled each of the last three years. So I'm wondering if a year from now, we'll be looking at 800 publications and if that's the case, I was wondering to what extent do you think your new SP-X launch could play a role in driving oncology and then related to that was wondering if you could give us a sense of what the multiplexing within the core plex assays in oncology might look like and in which types of cancer do you think the SP-X will be used the most?

Yeah. I was texting nonstop to a lot of my pancreatic like MD Anderson, there's a guy named [indiscernible] presented at PPH and there's a lot of pancreatic interest given, Alex Trebek’s situation of announcement and so this, I'm really excited about going after cancer and the SP-X is the ten plex and it's looking at 10 different cytokines which are the proteins of the immune system and we selected what we consider to be the most important ones. And the challenge in the immune system is these cytokines typically at baseline levels when you're healthy and the immune system hasn't been up regulated, the challenges you can't measure them with today's technologies. And so I think about a third of those 10 plexes that we're launching, we're going to be able to see baseline levels, which is a game changer because you really want to see the first movement of those cytokines, particularly when you're looking at response to a treatment because the way these immune therapies are working is that they're tricking the immune system, to basically see the cancer. What's happened historically is the cancers are able to hide in the immune system and so the immune system doesn't fight them. And so many of these new immune-therapies are being triggered to see the cancer and then fight the cancer and so you want to up regulate based on the treatment, but many times, it goes into what's called cytokine release or cytokines storm, where the patient ends up basically dying through the toxicity of that elevation from that drug. And so the ability to see very early stage movements can lead to getting response understanding much earlier. And I think there's some evidence of some researchers that I've talked to that say hey, today if you…

Okay. And my last question, maybe for Joe, the number of instruments, I think you said at 278, just wanted to ask a clarifying question. Are those orders or are those installed and generating consumable revenue? And then I also wanted to ask about the pull through on the HD-1, I think you had increased it to 60,000 per box per year at the end of Q3. Where are you now? And where do you think that can go at the end of 2019?

So the 278 is actually installed units out in the field that are generating consumables revenue.

And Mark, the way we've been saying it is that six months after an instrument is installed, we're going to be able to get a third, you should model a third of the list price as being what we're going to be able to pull through it from that point forward. So that's the way we've been trying to get everyone to model, look at our total instrument revenue and then a third of that is what you should see repeating six months later and so I think that the HD-1 did deliver pretty good numbers. We set out saying 50,000 for the year and we were at 40,000 the previous year and we ended up I think at 55,000 at some point. So we were approaching heading towards 60,000. And I think our list price on those are like 155, so that was a little bit above one third and so I think that product has been out there longer and that's what you can expect. The HD-X, we're hopeful is going to even provide even more excitement eventually, they even drive that further. The SR-X, right now, I would say it's probably 25,000 is what we're trying to get to with that product line and we really haven't had much of a six month kick in on those yet. And SP-X, again it's the same price point as SR-X. We have some test beds that are even significantly beyond the one third, but our hope would be that we can keep maintaining that and so we feel pretty good that that's a good place to model us.

I think we probably should cut it off. We’re beyond time, but I can't thank everybody enough. Great call and we'll follow up with you as any of you have questions. Thank you very much.

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