Welcome to Glaukos Corporation's First Quarter 2021 Financial Results Conference Call. A copy of the company's press release, issued after the market closed today, is available at www.glaukos.com. At this time, all participants are in a listen-only mode. After the speakers' presentation, there will be a question-and-answer session. This call is being recorded, and an archived replay will be available online in the Investor Relations section at www.glaukos.com. I will now turn the call over to Chris Lewis, Senior Director of Investor Relations and Corporate Strategy and Development.

Thank you, and good afternoon. Joining me today are Glaukos President and CEO, Tom Burns; CFO, Joe Gilliam; and COO, Chris Calcaterra. Following our prepared remarks, we'll open the call to questions. To ensure ample time and opportunity to address everyone's questions, we request that you limit yourself to one question and one follow-up. Please note that all statements other than statements of historical facts made on this call that address activities, events, or developments we expect, believe, or anticipate will or may occur in the future are forward-looking statements. These include statements about our plans, objectives, strategies, and prospects regarding, among other things, our sales, our products, our pipeline technologies, our U.S. and international commercialization, integration and market development efforts, the efficacy of our current and future products, our competitive market position, financial condition, and results of operations, as well as the expected impact of the COVID-19 pandemic on our business and operations. These statements are based on current expectations about future events affecting us and are subject to risks, uncertainties, and factors relating to our operations and business environment, all of which are difficult to predict and many of which are beyond their control. Therefore, they may cause our actual results to differ materially from those expressed or implied by forward-looking statements.

Thank you, Chris. Good afternoon to everyone, and thank you for joining us today. We hope everyone is staying safe and doing well. As we pass the anniversary of the initial pandemic-related shutdowns and reflect on this past year that has challenged all of us in extraordinary ways, I am confident that we have evolved into a more efficient and stronger company, well positioned to advance our mission and execute our ambitious plans. We remain focused on our near-term execution as we drive new adoption and deeper penetration globally for transformative MIGS and ilink solutions. At the same time, this company is advancing novel platforms with the goal of disrupting conventional treatment paradigms, improving the existing standard of care, and enriching the lives and treatment alternatives for patients worldwide. We continue to invest in and advance our fulsome pipeline based on our core platforms, where we anticipate and are planning for a robust cadence of new product introductions over the coming years that have the potential to significantly expand our addressable market opportunities. We are confident that the investments we're making today will drive Glaukos forward as a unique strategic vision care leader with tremendous potential for long-term growth and profitability. Today, Glaukos reported first quarter net sales of $68 million, up 23% versus the year-ago quarter. Joe will discuss our financial results and forward outlook in more detail later in the call, but I will begin that discussion here by providing an update on the continued commercial progress and the market conditions overall. Fueling our strong start to the year was solid execution on our key strategic initiatives across our Glaucoma and Corneal Health franchises globally. We have been pleased with the continued strong recovery trends in the market overall, and our business specifically, through the first quarter and into April. While first quarter procedural recovery trends were somewhat volatile and remain fairly variable based on geography, I have been encouraged by how physicians' offices, ASCs, and hospitals continue to navigate the new normal as we progress closer to a more stable market environment, leaving us cautiously optimistic for our ongoing improvement from here through the remainder of this year. During the first quarter, we advanced the U.S. commercial rollout of the iStent inject W, our newest MIGS technology, designed to offer ophthalmic surgeons the same established safety and efficacy of iStent inject, with added benefits designed to optimize stent visualization, streamline implantation, and deliver procedural predictability. The feedback and real-world results for iStent inject W remain very positive, which reaffirms our confidence in the commercial prospects. In fact, 99.8% of our inject sales in the first quarter were iStent inject W, strong evidence of both our rapid commercial rollout progress and the overall marketplace acceptance of this important technology. The successful iStent Inject W rollout, along with improving market recovery dynamics, have allowed us increasing in-person access to practices and accounts, although still on a more limited basis than before the pandemic. As a result, we have been pleased by the continued strength of our new surgeon training activities throughout the first quarter. The various virtual and digital programs we've implemented over the past year aimed to support our customers during COVID-19 also continue to be utilized in meaningful ways, and I believe these efforts have helped to deepen our customer relationships over the past year and prepare us for the future well beyond COVID-19. As a corporate pioneer of MIGS, we feel it's our responsibility to help expand access to care for all patients. As a testament to this, we were delighted to launch a new patient-centric initiative in honor of World Glaucoma Week in March, including a global education and awareness campaign designed to raise awareness surrounding the risk and prevalence of glaucoma. We also partnered with eye care institutions across the United States to offer free glaucoma screenings. We are proud to support the sight-saving work of the World Glaucoma Association through these patient and healthcare professional education initiatives and further our goal to help make safe, effective, and impactful glaucoma care more available to a growing patient population worldwide. Outside the United States, we were pleased with the strong performance in our Glaucoma franchise during the first quarter, as we drive deeper penetration and broader adoption of MIGS around the globe. International growth during the first quarter was led by the recovery in the Asia-Pacific region, including Japan and Australia, in particular. Like the U.S., we also advanced the commercial rollout of iStent inject W during the first quarter in key international markets, including Australia, Japan, and several European countries. We believe the successful iStent inject W rollout, along with several recent accomplishments, including stand-alone indication approval in Australia, regulatory approval in India, and continued progress across many of our key market access initiatives, leave our international Glaucoma franchise well positioned to drive sustainable long-term growth. Going forward, we plan to continue to support and grow our quality experienced OUS surgical sales teams, while working to optimize the reimbursement coverage and payment landscapes, train surgeons and leverage our compelling clinical data to grow MIGS adoption, and drive deeper penetration in our 16 international countries where we have a direct market presence today. We are also evaluating and have been making initial investments in potential future direct and hybrid markets where favorable opportunities and reimbursement pathways exist. In Corneal Health, we have also demonstrated strong performance during the first quarter, driven by exceptional year-over-year U.S. Photrexa sales growth of 51% and continued healthy momentum in new U.S. account starts. We continue to opportunistically expand our U.S. Corneal Health commercial team to fuel the execution of our commercial strategies and market development initiatives, including driving increased awareness of keratoconus broadly across the optometric and ophthalmic community, advancing the diagnosis of this important debilitating condition. During the second quarter, we expect to officially complete our corporate integration activities with the successful transition of our Corneal Health franchise onto our ERP and CRM systems. This has been a technical difficulty since the close of the acquisition roughly 18 months ago. While we remain in the early stages of unlocking the combined organization's full potential, we are encouraged with this performance and focused on the opportunity ahead. Shifting gears to our pipeline, our goal is to leverage our development expertise and commercial infrastructure to provide a portfolio of solutions based on key platform technologies that meet the full algorithm of customer needs. In the first quarter alone, we announced several critical clinical data milestones for three of our key pipeline programs, including first, a two-year interim analysis of our ongoing three-year iDose TR Phase IIb trial showing compelling data that further underscores the potential for this technology to safely provide multiple years of sustained glaucoma pharmaceutical therapy. Second, strong twelve-month IDE pivotal data for iStent infinite achieving its primary efficacy endpoint and surpassing our internal expectations; and third, positive Phase III results for our next-generation corneal cross-linking Ilink Epi-On investigational therapy meeting the primary efficacy endpoint and demonstrating Epi-On's ability to halt or reduce the progression of keratoconus without removing the outer layer of the cornea. Each of these important clinical achievements reaffirms our confidence in these programs and their future commercial prospects. For iDose TR, we are pleased to announce we have completed patient enrollment and randomization in the first of the two pivotal clinical studies that make up the Phase III clinical program. We continue to progress towards enrollment completion in the second trial and anticipate enrollment and randomization completion for this study in the second quarter. The twelve-month Phase III trial results are expected to support our anticipated NDA submission for iDose TR in 2022, and we are targeting FDA approval for this promising technology in 2023. Regarding the PreserFlo MicroShunt, in April, Santen announced the delay of FDA approval. As they continue discussions with the agency, we will continue to closely monitor any developments associated with their ongoing FDA discussions and are hopeful to have more information and direction on this front as we move forward. For iStent infinite, we could not be more delighted with the outcome of the pivotal study. We are hard at work preparing for a regulatory submission over the coming months and continue to target FDA approval in late 2021. For Epi-On, we have successfully completed the initial transition to our new CMO partner, which we believe will provide us with the necessary infrastructure and scale upon potential commercialization of this important technology. We continue to target a U.S.-India submission for Epi-On in 2022 and the FDA approval in 2023. We also continue to advance our late-stage development of iPRIME, a highly complementary new viscodelivery device designed to be a truly minimally invasive system to further support the needs of physicians and patients. Beyond these important pipeline programs, we also continue to invest in and advance our key earlier stage R&D programs, including in dry eye, retina, glaucoma, and additional undisclosed projects. While these opportunities remain in preclinical developmental stages, we are encouraged with the initial progress we are demonstrating within these platforms and associated programs. One such program is our eyelid transdermal platform, where development efforts are focused on patented cream-based drug formulations that are applied to the outer surface of the eyelid for transdermal drug delivery in glaucoma and various corneal disorders, including dry eye. Further, we recently announced an expansion to this platform with the addition of presbyopia as a new investigational application, as well as broader future development rights with Intratus to go along with the promising R&D work we've completed thus far. We aim to advance several programs using this differentiated, noninvasive, patient-friendly therapeutic approach into clinical trials. Our pipeline has the ability to fundamentally transform Glaukos by significantly expanding our addressable markets over time. To enable this, we've built a strong balance sheet and are aggressively expanding our global infrastructure, strengthening our pharmaceutical expertise, and upgrading our systems. I am pleased with the execution of our key strategic initiatives and believe we are well positioned to advance our mission to create novel platforms that can transform the treatment of chronic eye diseases for the benefit of patients worldwide. In doing so, we strive to create a world-class global vision care leader, uniquely positioned to drive innovation across glaucoma, corneal health, and retinal disease. A core pillar of our drive to be a world-class company is an unwavering commitment to continual improvement as responsible corporate citizens. To this point, we recently released our 2020 sustainability report that significantly builds upon last year's inaugural assessment and highlights our continued commitment and progress on environmental, social and governance initiatives. Over the course of 2020, we invested significant time and resources into better understanding what drives sustainability at Glaukos, establishing meaningful goals to propel us forward on ESG matters, and examining how best to present our progress to our stakeholders. Continuing to grow and enhance our ESG policies and program is a key priority for us now and into the future, and we hope our 2020 sustainability report reflects that dedication. Finally, before turning the call over to Joe, I'd like to send a sincere welcome to two exceptional women who recently joined our Board of Directors. Ms. Denice Torres and Dr. Leana Wen. With more than 25 years of management experience in pharmaceuticals, medical devices, and consumer or healthcare, Denice is a highly accomplished executive who has led significant successful business transformations, including serving most recently as Chief Strategy and Transformation Officer for Johnson & Johnson's Global Medical Device business. As a practicing emergency physician, visiting professor of health policy and management at the George Washington University School of Public Health, and former Baltimore Health Commissioner, where she led the nation's oldest continuously operating health department, Leana is a sought-after and trusted expert on a range of health policy and public health issues. Each of these extraordinary women bring a wealth of relevant experience, perspective, leadership, and wisdom that will be invaluable to our growing global organization, and we are delighted to welcome them to the Glaukos board. So, with that, I'll turn the call over to Joe to discuss our first quarter 2021 financial results.

Thanks, Tom. As a reminder, I will be discussing our financial performance on a non-GAAP or pro forma basis and will summarize our GAAP performance later in my prepared remarks. I encourage each of you to review our GAAP to non-GAAP reconciliation, which can be found in today's press release as well as the Investor Relations section of our website. Glaukos' global consolidated net sales for the first quarter of 2021 were $68 million, representing year-over-year growth of 23%. As a reminder, our sales were materially impacted in the last few weeks of the first quarter 2020, as COVID-related restrictions emerged. These results to start the year exceeded our expectations and reflect the continued recovery, despite ongoing COVID-19-related headwinds and associated volatility. With respect to the pandemic impact, we believe the underlying markets continue to face mid- to high single-digit headwinds throughout the first quarter, with a pronounced softness in February due to spiking COVID cases internationally, as well as by the vaccine rollout and severe winter weather dynamics here in the U.S., but the latter was followed by a healthy rebound domestically in March that continued in April. Now turning to our U.S. Glaucoma franchise specifically, our first quarter U.S. Glaucoma sales were approximately $39.9 million, representing year-over-year growth of 22%, which we believe reflects a combination of pandemic-related dynamics, a stable competitive landscape and pricing environment, and underlying seasonality trends. Internationally, our Glaucoma franchise delivered first quarter sales of approximately $13.8 million, representing year-over-year growth of 20%. This performance reflects growing demand in many key markets and favorable foreign exchange tailwinds, which were offset by the ongoing pandemic impact in certain markets and a one-time catch-up provision associated with government rebates in France. The performance in the quarter was led by our Asia-Pacific region, including Japan and Australia, in particular, while the major European markets have experienced challenges associated with the pandemic, such as the shutdowns in the U.K. and France and other restrictive actions throughout the region. And unfortunately, the situations in India, Brazil, and Latin America generally remain quite challenging. In Corneal Health, first quarter net sales were $14.3 million, representing year-over-year growth of 27%. The first quarter performance was driven by U.S. Photrexa year-over-year sales growth of 51% to $11.4 million and a continued trend of healthy new U.S. Photrexa account starts, as our commercial integration and strategies continued to deliver, despite the pandemic. Shifting gears toward the remainder of our P&L, our non-GAAP gross margin in the first quarter was approximately 83.8% versus 83.6% in the same quarter in 2020 and 83.4% in the fourth quarter of 2020. This reflects continued strong gross margin performance in Corneal Health and Glaucoma, partially offset by the modest headwinds associated with the sale of Glaucoma inventory that had been produced less efficiently during the pandemic and geographic mix. It is worth noting that our non-GAAP adjustments to cost include substantial adjustments related to Avedro acquisition accounting. Our overall non-GAAP operating expenses were approximately $61.8 million in the first quarter of 2021, remaining below first quarter 2020 pre-COVID levels and consistent with the fourth quarter spending, as we continue to restore expansionary spending as the recovery warrants, a trend that we would expect to continue throughout 2021. Our non-GAAP SG&A expenses in the first quarter were approximately $40.7 million, up 1% sequentially compared to the fourth quarter, reflecting increased commercial spending, offset by lower administrative costs. Our non-GAAP R&D expenses in the first quarter were approximately $21.1 million, down 1% sequentially compared to the fourth quarter, as we continue to restore core R&D spending, earlier-stage pipeline programs, and human capital investments across the organization, offset in the quarter by lower clinical development costs. We finished the first quarter with a non-GAAP operating loss of $4.8 million and non-GAAP net loss of $9.5 million, or $0.21 per diluted share. Our GAAP net loss was $16.5 million, or $0.36 per diluted share for the first quarter of 2021. We also invested in approximately $17.2 million of capital expenditures in the first quarter, a significant increase versus prior periods. As we've entered the construction phase of the enhancement and expansion of our facilities in Southern California and Boston to meet our expanding development and operational needs, a trend that we would expect to continue for the remainder of the year. As of March 31, 2021, we had cash, cash equivalents, short-term investments, and restricted cash of approximately $417 million, compared to $414 million at the end of 2020. Finally, I will make a few comments on the state of our markets and opportunity today and how we believe things are unfolding for 2021. We believe the competitive landscape and pricing dynamics remain stable across each of our major business areas. And as Tom mentioned earlier, our integration efforts and strategies are driving increasing penetration in Corneal Health alongside a successful launch of iStent inject W globally in Glaucoma. Not surprisingly, the dynamics associated with COVID-19 and its variants remains fluid. And as discussed, the overall ophthalmic markets still face headwinds and volatility, most recently in a few U.S. states and numerous countries around the world that have experienced what we hope is a final wave. Having said that, we have been encouraged by the overall trends exiting the quarter, which I discussed earlier. And as we put all this together in the context of our expectations going forward, we expect second quarter 2021 net sales to increase sequentially to approximately $70 million to $72 million, which reflects our typical underlying seasonality patterns, the broader recovery trends I discussed earlier, international headwinds related to COVID, and potentially unique summer holiday dynamics. As we look forward towards the second half of 2021, assuming the pandemic trends continue to gradually improve from here, as anticipated, we would expect the underlying markets to normalize back to 2019 levels, generating sequential improvements each quarter for our business over the remainder of the year. And with that, I'll now turn things back to Tom for a few closing remarks.

All right. Thank you, Joe. I would like to conclude by acknowledging how proud I am of the actions our organization has taken throughout the COVID-19 pandemic, while advancing our key strategic priorities in a rapidly changing environment. We are focused on near-term execution and excited about our long-term future, where in just the next three years, we expect to have several major new product introductions. Beyond that, we have a fulsome portfolio of pipeline opportunities, as we seek to build and expand upon our core microsurgical and sustained-released pharmaceutical platforms. The strong foundation and team we have built leaves me confident in our ability to execute on our plan as we strive to create a strategic vision care leader with disruptive franchises across Glaucoma, Corneal Health, and Retinal Disease. So, with that, I'll open the call to questions.

We have our first question from Brian Weinstein from William Blair.

This is Griffin on for Brian. Just the first one here, on the deferred cataract surgeries from the pandemic, how should we think about the pacing of churning through that backlog and the magnitude of the tailwinds there?

Sure. Griffin, it's Joe. I'll start off, and if Chris wants to add any color, he can. So clearly, we've talked about for a while here the generation of or generating a backlog for many practices throughout the country and world. I think as we look forward and think about this, I think the actual playing out of that backlog will be more elongated. You have to take into consideration the actual operating dynamics for most of these accounts, where there are still only so many surgeons in so many hours in a day for them to be providing procedures. So I think as they work their way through it, it should be a tailwind for the overall market, but one that's perceived over many quarters versus many months.

Okay. And then just one more. Can you revisit the investments that you're going to need to commercialize some more of these high-profile products in your pipeline? Maybe how are you preparing for regulatory and reimbursement considerations there?

So, as we think about prioritizing the commercial investments associated with our pipeline, there's a lot of planning going on. We've talked about, I think, historically, each one is a little bit different. As we think about products like iDose and Epi-On, obviously, those are highly synergistic with the commercial infrastructure that we have today. And so, while we would foresee incremental investments there, whether it be, as you mentioned, market access reimbursement, marketing, or to a certain extent, the commercial infrastructure, those are highly synergistic with what we have. And as we continue to sort of go beyond that, and as Tom talked about some of the other earlier-stage programs we have, like the transdermal drug delivery platform, at that point, you start thinking about larger-scale investments in the broader infrastructure to support an opportunity like that on the pharmaceutical side.

Understood. And just one more quick one on Epi-On. Can you talk about how you think about segmenting the market between Epi-On and Epi-Off? And do you anticipate the need of a separate reimbursement code for Epi-On? So maybe what does that look like and timing there?

Yes, Griffin, I'm happy to address that. This is Tom. And so, as I said before, I think our positioning could follow in the line much like we do in Glaucoma, which is position according to disease stage severity. So, when we're looking at Epi-On, we may position that for more earlier intervention patients, and with Epi-Off, we may position that for later-stage or more progressive keratoconus patients. We don't have any direct comparisons between the two procedures, but it is our conceptual belief that Epi-Off probably delivers more of a reduction in Kmax versus the Epi-On procedure. And so thus, I think physicians will see it the same way, and we think they'll want to carry both of these different procedures into the marketplace to best serve patients. With regards to how we seek reimbursements, I would just say we have no obligation either way, but we can choose to create a separate J-code for Epi-On if we choose to do so. Those decisions are under consideration, and I'll advise you once I feel that I'm making the appropriate decision for investors.

We have our next question from Matt O'Brien from Piper Sandler.

This is Drew on for Matt. I just wanted to start off a little bit on the performance of the business as of late. Maybe you could kind of help us understand what you're seeing on the ground as far as what percentages of your customers are open back up to capacity, maybe exit rates March into April, if you're willing to provide. And then, second part is a bit of a clarification.

Drew, it's Joe. I'll handle the first part. In terms of physicians' offices being open and ambulatory surgery centers and facilities, in the U.S., I would say that they're all open to different degrees. There's still a restraint on how many patients can come into the practice, still some headwinds in terms of how reps are able to get into these practices, and even into the OR, but that is definitely loosening up. As you look across the globe, you do see different scenarios. Here recently in France and Germany, things were really shut down because of the second wave and or third wave and spike in COVID cases, and so patients are being restricted both in terms of practices and offices. All in all, it continues to get better. But on a global basis, there's still a headwind from these COVID-related issues. Okay. Then I'll take the second part of your question. First, on exit rates, building upon what Chris was saying, I think for us, the U.S. Glaucoma franchise, as well as Corneal Health, in particular, saw a very strong sequential improvement from what I'll call a lull in February through into March, and then again into April, so good trend lines there. The international Glaucoma business is a bit more mixed for all the reasons that Chris was just saying. I think in the Asia-Pacific region, we've seen strong trending, both in the fourth quarter of last year, but then again in the first quarter, and that's really continued. While on the opposite side of that spectrum, we've seen the Latin America, Brazil, etc. markets continue to struggle with COVID and the related dynamics, and that continued through the first quarter and has continued really through the month of April. Meanwhile, in Europe, you see relatively mixed results, where we saw a degree of recovery in the fourth quarter, but it's really been somewhat muted since that point, as some markets have moved forward and other markets have taken a step back as they handle this third or fourth wave of COVID, depending on how you look at it. As it relates to the 2019 comparison and we talk about markets getting back to more normalized levels relative to 2019, you referenced, obviously, our results for the full year. We're talking about those trends getting back to that level in the second half. And to get any more precise than that, I think, would be a little bit difficult at this stage.

Okay. That's super helpful. And then can you just remind us or give us an update on the CPT coding process, where you sit with the Category I transition and then the Cat 3s for stand-alone and iDose? And then, as far as pricing of those codes, can you just remind us of the steps of that process and what your expectations are for some of those new codes, or where some of those new codes will be priced maybe relative to your current iStent business today?

Yes, Drew, I'll be happy to take that one. So let's first step back and remind ourselves how favorable the AMA CPT committee was for the business, and this occurred in October of last year. A couple of major favorable developments came out of that. First of all, the creation of the committee of a Category III stand-alone code for iStent inject, and then a separate creation of a Category III code for iDose. And these are two major seminal events that we were seeking for some time, and we were able to secure those codes. And once we have those codes in place, we are then able to really kind of aggressively pursue reimbursement at the carrier level for both of those, and I can discuss that a little bit later how we will do that. Second major development, by combining those two codes together, this gives us a tremendous opportunity for our vision in the future of using iDose in combination with the trabecular bypass prosthetic procedure, which I think will become the norm for patients with more moderate to progressive glaucoma. So that sanctions and gives us the ability to move forward. The third major event that came out of that meeting was the movement from the committee to transition the Category III 0191T code into a transitional code that would combine both cataract surgery and the implantation of a trabecular bypass device. And so, as we said, just to give you a status update on the professional fee side, the new Category I CPT code is referred to the AMA RVS update committee, the RUC committee, to conduct physician surveys in order to assign a relative value unit scale and into a professional fee calculation. So that survey, to our knowledge, is going on as we speak, and the RUC committee will make a recommendation to CMS, and CMS will publish a proposed rule in the early part of July. On the facility side, we are working very closely, as we convert from a Category III to Category I, with the specialty societies, including the American Academy of Ophthalmology and the ASCRS, among others, including the American Glaucoma Society, to help present a case to negotiate facility fee reimbursement for the hospitals and ASCs that will best represent and fairly position these products with our customers. And so that also, that CMS proposed rule recommendation should happen in July as well. And then, once the proposed rule goes into place, there'll be a commentary period, and CMS will issue a final 2022 rule, probably in late October, early November of this year, which will be effective in January. So, as we've said before, these are very, very favorable developments on the whole for Glaukos. Having a stand-alone code for the iStent infinite, for instance, will coincide with the product launch, gives us great legs to be able to pursue reimbursement through a local coverage determination in each one of the MACs, something we've become pretty good at, given our history with iStent and with other products. With iDose, we'll be holstering that until we near approval, but then we'll have the ability to, as well, approach the carriers on a local coverage determination basis. And typically, what the carriers do, as you know, they'll crosswalk this to a like Category I code to determine their discretionary view of what the professional fee reimbursement for that product will be. So, again, that falls within our power alley, once we have approval. And then, of course, we would seek a separate J-code to be able to carve out the iDose device, once we receive commercial approval. So, as we've said before, we, on the whole, are very excited about what came out of the committee. There are obviously always a variety of scenarios that can materialize when a CPT code moves from Category III to I. On the professional fee side, it's our expectation that payment should most likely decrease versus the average pro fee levels under the current Category III designation, largely because the RBS system will view it as an ancillary procedure, rather than giving them the full perioperative component. On the facility fee side, there's a variety of scenarios that span from negative to neutral to quite positive, and we work very, very closely with the associations to make sure that we best represent what we've accomplished in pioneering and creating this market class category. So I think that gives you the full view, for you and for investors, and we look forward to continuing to prosecute. In any event, we are prepared to move forward and best represent the commercial interest of the business.

We have our next question from Robbie Marcus from JPMorgan.

This is Alan speaking on behalf of Robbie. I have a quick question regarding the quarterly trends and a follow-up. In reviewing your guidance for the second quarter, it appears you're not projecting growth over 2019 levels, which is similar to what you did in the first quarter, despite mentioning that the first quarter faced challenges both domestically and internationally. I'm hopeful that the U.S. will continue to show improvement, even if the international side remains somewhat weak. Could you share what is influencing this cautious approach? Is it purely due to standard COVID-19 related caution?

Yes. Thanks, Alan. It's Joe. I think a little bit of both. I mean, the reality is, we've seen positive trend lines at least once before during this pandemic as we went into, call it the October timeframe at the beginning of the fourth quarter, only to see some, obviously, setbacks, as another wave of COVID kind of took over here in the U.S. as well as internationally. So, as we continue to navigate the dynamics and watch some of the hotspots with emerging variants and the like, I think it does make sense to still be a little bit on the cautious side. I think the second dynamic that we're trying to factor in, you'll recall, with seasonality in our business, one of the aspects over the course of the middle part of the year is just summer holiday season, both here as well as in some of the international markets. And as I think we all come out of this long COVID stretch, I think it's our expectation that people are going to take some time off, and that could cause a little bit of disruption relative to traditional trends as we get later into the quarter.

Got it. And then just a quick follow-up on iDose. It's really nice to hear that you finished enrolling the first trial and that you plan to finish enrolling a second trial pretty soon. But when should we expect to see top line 3-month efficacy data? Or should we, similar to the Phase II trial, wait to see the full year results like in 2022?

Yes. So, Al, we haven't committed either way, but I will tell you that I think I would be more inclined to show the three-month data when we have locked it, and we've analyzed it to show that to investors, rather than waiting for the twelve-month data. And I think as well, I'd be inclined to show the three-year data from the Phase IIb study, because I think that will be important when we start to gauge the longevity of this device, which has really far exceeded our initial expectations.

Next is John Block from Stifel.

This is Trevor speaking on behalf of John. I wanted to explore the recent trends you mentioned earlier. In the fourth quarter, you noted that some patients were choosing to postpone procedures due to the upcoming vaccinations. Could you provide an update on how this trend has evolved in the first quarter, especially considering that many individuals in older demographics are now vaccinated? How has this affected the trends you observed in February, March, and April? If you could provide any quantifiable insights, that would be appreciated.

Trevor, it's Joe. When we made that comment, it was during the fourth quarter call and it related more to our observations in February than to the fourth quarter performance itself. In particular, in regions where vaccination efforts were ramping up, such as the U.S. and the U.K., we noticed a slight pause as we believe many patients chose to wait until they were fully vaccinated before undergoing their procedures. And so, that certainly was a factor in February. It's hard to separate that versus some of the other things we saw in that month, which was pretty extreme winter weather, as you will recall, throughout the South and in the Northeast here in the United States in particular. But those two things definitely led to a pronounced softness in that month, and we've thankfully seen a nice recovery from that point, both in March and then again in April.

Okay. Great. And then maybe just a follow-up on iPRIME. Could you give us any comments on how you intend to position that in the market? Is it going to be something that you'd bundle with another device, or would you sort of stand on its own?

Trevor, this is Chris. And we hadn't really disclosed that. We're excited about having yet another product in our bag. We see this as potentially as a stand-alone as well as complementary to our trabecular bypass products. Anytime you have a multitude of options, it always puts you in a good position in terms of negotiating pricing contracts with ASCs and hospitals.

Next is Ravi Misra from Berenberg Capital Management.

Devin for Ravi for the Berenberg team here. I wanted to ask you, in regards to the COVID normalization and surgeon training, how do you see that playing out in the second half of '21? Is that kind of in line with the rest of the business and opening up, or do you see that kind of bifurcating between global and U.S.?

Yes, this is Chris, and we haven't disclosed any specific numbers around physicians trained. What I will say is that things have definitely started to open up. We're pleased with where we were in the first quarter. And with the introduction and excitement around iStent inject W, we continue to train physicians, and we would expect to do so on a go-forward basis.

And I think with respect to your portion of the question on international versus the U.S., obviously, it's an important driver for our business, regardless of geography. And we continue to train doctors worldwide.

Okay, great. I have a quick follow-up. You mentioned restoring expansionary spending in 2021. Can you provide some insight into how the sales force expansion relates to that, especially with the new product line like iDose CR and its pharmaceutical aspect? When does the expansion typically begin in relation to commercialization? Is it a year ahead or a few quarters ahead? I'm just trying to understand the timing involved.

Yes, it's Joe. Chris, feel free to add if you'd like. I don't believe that's relevant to 2021. Regarding your question about iDose, it doesn't constitute a major expense for 2021, aside from our usual efforts in health economics, market access, and reimbursement in advance. From a commercial infrastructure perspective, we wouldn’t be making significant expenditures in 2021. As you start getting into 2022 and transition to 2023, you'd expect a gradual uptick there, as you begin to prepare for commercialization and launch, both from a marketing standpoint as well as commercial infrastructure.

I want to emphasize that we will leverage our existing sales organization for iDose. While it is a pharmaceutical product, it will be implanted in a physician's office, an ASC, or a hospital, so we will heavily rely on our current sales team.

Next is Anthony Petrone from Jefferies.

This is Briana on for Anthony. I have two questions, and I'll ask them upfront. Is the Ivantis case trial still on track for October, is my first question. And then second is a follow-up to some of the reimbursement questions that were asked. So, with iStent physician fee code changing from Category III to Category I, do you expect the stock to be sensitive to what CMS proposes for the new physician payment levels? And then, if so, how much do you think the stock would move on these payment levels that are plus or minus 20% from the status quo in the $900 to $1,300 range?

Well, Briana, I'll address your first question about the Ivantis trial. The location for the trial will be Santa Ana, Southern California, where they have indicated that trials will begin in May, covering both civil and criminal proceedings. We anticipate that the trial will start in late September, and we are preparing accordingly. We remain very confident in our position, supported by several motions that have been resolved in our favor. We will keep investors informed of any updates. And then, Briana, it's Joe. I'll try to take a stab at the second part of that question. Obviously, I wouldn't make predictions with respect to stock price movements on anything related to our business. But what I can say is, as you think about the Category I code conversion and the physician fee that you asked about, clearly, we have some experience here. If you think back to the dynamics around the Noridian region that really took hold, I believe, in the middle part of 2017 and only recently had some recovery in that physician fee. And at the time, we told investors to expect that while we didn't welcome that pullback in the physician fee, that what we were seeing was a modest headwind to growth as it related to that, but not a significant impact to the net underlying demand. And so here, I think that's something people will have to take into consideration as they think about any movement around the physician fee later this year.

The only thing I'll add is that trabecular bypass is becoming more of a standard of care, and as a result, more physicians are performing it, and more patients are requesting it, which I believe is an important factor as well.

We have our next question from Steven Lichtman from Oppenheimer.

This is David on for Steve. Just starting off with the iStent infinite slated to launch towards the end of this year, could you maybe just refresh us on your initial market assumptions, reimbursement efforts, and any commercial scale or investments necessary ahead of that launch?

Yes. I'll take the first part of this. This is Chris. So we're hoping for approval by the end of the year. We would launch shortly thereafter. It will come out as a Category III. We're expecting the code or the Category III designation in January, similar to what we did with iStent when that was approved in 2012. But we will be working with all the MACs and commercial payers to get a fulsome reimbursement, both for the facility fee and for the physician fee. It will likely be – have a label that is approved for advanced glaucoma, and that's how it will be positioned by our organization. So I would see that that will start as a slow ramp up and will continue to grow over time as we get more payment from these organizations.

I think from a market size standpoint, I would just add that out of the gate, we see it as a couple of hundred thousand, call it 200,000 potential procedures a year in the United States, larger than that on a global basis. And over time, from a market development standpoint, we hope to expand that. And I've said in the past that that could ultimately be as large as, let's call it, 0.5 million procedures a year in the United States, depending upon how that market evolves.

Great. That's helpful. And then just one more on the Corneal Health business. You guys posted another strong quarter here, and just curious, can you talk about maybe what's been driving the growth there? Is that more a function of greater utilization within existing accounts or expanded installed base?

Yes, this is Chris. I would say it's a combination of factors. It includes expansion within existing accounts, new starts, and training ODs and physicians to identify keratoconic patients. It also involves implementing customer-friendly programs to simplify the equipment acquisition process. Additionally, we've worked extensively on reimbursement to ensure that payments are comprehensive and reliable. There are many aspects involved, including effective direct-to-consumer campaigns.

No further questions at this time. I turn the call back over to the company.

Okay, so with that, I want to thank all of you for your time and attention today. We hope everyone is staying safe, and thank you for your continued interest in Glaukos. Goodbye. Have a great day.

This concludes today's conference call. Thank you for participating. You may now disconnect.