Flexion Therapeutics, Inc. (FLXN) Q1 2019 Earnings Call Transcript

Flexion Therapeutics, Inc. (FLXN)
Q1 2019 Earnings Call
May 8, 2019, 4:30 p.m. ET

Contents:

• Prepared Remarks
• Questions and Answers
• Call Participants

Prepared Remarks:

Operator

Good afternoon, ladies and gentlemen, and welcome to the Flexion Therapeutics first quarter 2019 financial results conference call. My name is Kevin, and I'll be your coordinator today. At this time all participants are on a listen-only mode. Before we begin, I would like to call your attention to the slides the company will present today. The slides can be viewed directly via the webcast on Flexion's website under the Investors tab, or on the EK the company issued this afternoon. We will be facilitating a question and answer session at the end of today's call. If at any time during the call you require assistance, please press * followed by 0 and a coordinator will be happy to assist you.

I will now turn the call over to the company.

Scott Young -- Vice President of Corporate Communications & Investor Relations

Good afternoon. This is Scott Young, Vice President of Corporate Communications & Investor Relations. The earnings release and slides we issued this afternoon and an archive of this conference call can be found on the company's website at flexiontherapeutics.com.

Today's call will be led by Flexion's Chief Executive Officer, Dr. Michael Clayman; and he is joined by David Arkowitz, Flexion's Chief Financial Officer.

On today's teleconference, we will be making forward-looking statements that include commercial, financial, clinical, and regulatory projections. Statements relating to future financial or business performance, conditions or strategies, and other business matters, including expectations regarding net sales, operating expenses, cash utilization, clinical, regulatory, and commercial developments, and anticipated milestones, are forward-looking statements within the meaning of the Private Securities Litigation Reform Act.

Flexion cautions that these forward-looking statements are subjected to various assumptions, risks, and uncertainties which change over time. Additional information on the factors and risks that could affect Flexion's business, financial conditions, and results of operations are contained in Flexion's form 10-Q for the quarter ended March 31, 2019, filed with the SEC today, and other filings, which are available at www.sec.gov as well Flexion's website. These forward-looking statements speak only as of the date of this call, and Flexion assumes no duty to update such statements.

I will now turn the call over to Flexion's CEO, Mike Clayman.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Thanks, Scott, and thank you all for joining the call. As usual, during today's teleconference, I'll provide an update on Flexion's business performance, including our progress with ZILRETTA's launch, recent regulatory and clinical developments, life cycle management activities, and FX201, our preclinical gene therapy program.

Following that, David will cover our first quarter financial results, and importantly, he will also walk through new commercial metrics, which we believe will provide our investors with much better visibility, and the key elements of the launch, and ZILRETTA's uptake in the market.

Finally, we will open the line and take questions.

To begin, as we announced in our earnings release this afternoon, we reported ZILRETTA net sales of $10.6 million in the first quarter. We see this as solid progress, and it gives us confidence reaffirming our full year revenue guidance of $65-80 million. Additionally, as we announced in our press release, preliminary net sales of ZILRETTA in the month of April were $5.1 million.

As a matter of practice, we do not provide real-time sales updates, and we have no plans to do so on future calls. In this circumstance, we thought it important to provide our investors with this recent data point, which is directionally encouraging and correlates with changes we have implemented in our commercial organization.

In January, we appointed Steve Myers as our new Vice President of Sales. Steve joined the Flexion sales organization as a regional sales director well before the launch of ZILRETTA and has rapidly risen through the ranks based on outstanding performance and leadership. He has deep knowledge of the buy and build space, knows what good looks like, and is a dynamic and effective sales leader who has an innate ability to get the best from his team.

In conjunction with his appointment, we realigned our structure to have him report directly to me. With that change in accountability, we quickly introduced a number of sales-effective initiatives and made other personnel changes to strengthen the performance of the entire sales organization. We believe that realignment has resulted in demonstrable improvements in our sales performance.

In addition, we also believe that the permanent J-code is beginning to have some impact on ZILRETTA revenues, and this should continue to be a positive influence on sales. Over the past several months, we have seen growing momentum, and the esprit de corps of our field organization has never been higher.

In related changes, we made the strategic decision to hire a Chief Commercial Officer, or CCO, who can help us ensure we realize ZILRETTA's fullest potential. As a result of this change, Dan Deardorf will leave Flexion in the middle of May. Dan did an excellent job building our commercial infrastructure and preparing us for the launch of ZILRETTA. We are tremendously grateful for all of his contributions and wish him all the best in his next endeavor.

As for the CCO position, a retained search is well under way. We are seeing quality candidates and proceeding with a sense of deliberate urgency in finding the right professional to lead the commercial organization. We will keep you apprised of any decision at the appropriate time.

With respect to other commercial highlights, at various time points along the launch, we conduct awareness, trial, and use surveys, or ATUs, would provide important insights about the effectiveness of our commercial strategy. The results from an ATU survey conducted last month demonstrate that we are making appreciable progress in the market. Specifically, the survey showed that 74% of the 120 orthopedic surgeons sampled had awareness of ZILRETTA, and 32% had administered the product.

By comparison, an ATU conducted in February 2018 indicated that 42% of 118 orthopedic surgeons sampled were aware of ZILRETTA, and only 9% had administered the product.

While sales are the definitive measure of ZILRETTA's adoption, the ATUs provide several important insights. First, awareness of and clinical experience with ZILRETTA is building. And second, we are still only just scratching the surface of this product's potential. David will provide further color when he walks through the new commercial metrics, and they present an encouraging picture of how ZILRETTA adoption and utilization continues to grow.

As for ZILRETTA's clinical performance, I won't belabor the point, but I'd be remiss if I didn't mention that compelling patient anecdotes continue to come in on a daily basis. Whether it is the hiker who is able to climb again, the woman who is able to walk her dog without intolerable pain, the prescribing physician who can walk up and down stairs pain-free for the first time in years, or the personal experiences of our colleagues and family members, each of these serves as inspiration to all of us at Flexion.

They provide a daily reminder that there are many more patient stories waiting to be told. And we believe there will be a day when ZILRETTA is the standard of care for all patients with OA knee pain.

Moving to our regulatory and clinical development activities, we have had active and productive conversations with the FDA regarding our supplemental NDA to revise the ZILRETTA label and remove the limitation of use statement that currently exists. As we previously reported, we have a PDUFA date of October 14, and based on our belief in the strength of our repeated administration data, we remain optimistic about the eventual FDA decision, which we fully expect will come by that date.

With respect to our line extensions and life cycle management plans, at the end of 2018, we enrolled the first patient in our double-blind placebo-controlled Phase 3 B trial to evaluate the safety and efficacy of ZILRETTA in patients with hip OA. That trial has been enrolling patients throughout the first and second quarters. However, we were recently made aware of a non-safety related product administration issue, which resulted in the inability to deliver a full dose of ZILRETTA in a small number of participants. As a result, we have paused recruitment of the trial as we work with investigators to identify and address the root cause.

With that said, this issue is specific to administration in the hip, has not been a problem with knee injections, and we do not expect it will impact our plans to initiate Phase 2 studies in shoulder OA and adhesive capsulitis later this year.

As for recent publications, in April, a post hoc analysis of data from the pivotal Phase 3 trial of ZILRETTA was published in Advances in Therapy. The findings indicated that patients with unilateral OA knee pain experience significant and durable pain relief with a single intra-articular injection of ZILRETTA compared to immediate-release triamcinolone acetonide as measured by average daily pain intensity scores. These results suggest that bilateral knee pain may have been a confounding factor in the pivotal trial which assessed the impact of ZILRETTA treatment in only one knee.

Additionally, an independent evaluation of clinical data for ZILRETTA conducted by Adis Drug Review was published in the journal, Drugs. Their assessment included data from six clinical trials conducted over the past seven years, which evaluated 1,347 patients, 613 of whom were treated with ZILRETTA. The evidence-based evaluation concluded that ZILRETTA provided effective pain relief, while being generally well tolerated, and it expands the treatment options for OA knee pain. Both of these publications provide additional insights from the ZILRETTA clinical trial experience and bring a deeper understanding of the overall potential benefit of this important therapy.

Finally, with respect to FX201, our intra-articular gene therapy product candidate, our GLP toxicology studies are advancing well, and pending successful results from these, we remain on track to file an IND and initiate first-in-human clinical trials in the second half of 2019.

In closing, we are roughly six quarters into the launch and we have growing confidence in ZILRETTA's ability to make a meaningful difference in the lives of patients with OA knee pain, the important role it can play for physicians in effectively treating those patients, and the value it can bring to our shareholders. We firmly believe ZILRETTA can and will become the leading branded IA therapy for OA knee pain, and we will remain tireless in those efforts until we achieve that goal.

At this point, I'll turn it over to David to discuss our financial results. But before I do, it's worth noting that he joined us almost one year ago to the day. With a full year at Flexion and broad experience in commercial companies, David brings an invaluable perspective to our commercial efforts, and he was instrumental in working with our commercial leadership team to develop the new metrics he's about to share with you.

David Arkowitz -- Chief Financial Officer

Thank you, Mike. With that, I'll first walk through the new metrics, and then I'll briefly cover the first quarter financials.

To start, we appreciate that the lack of meaningful monthly prescription data from the usual third-party sources may contribute to a sense of opacity when it comes to ZILRETTA sales, and I want to reiterate Mike's earlier comment that we develop these metrics to provide better visibility and insights for our shareholders and analysts.

Additionally, we did not develop these in isolation, and they reflect input that we've received from our investors and other stakeholders. That said, expect that we will revise and refine these over time based on their utility, and we will continue to solicit and incorporate your feedback to the extent possible.

So, let me direct you to slide two, with some new key metrics that provide important context on the progress of the launch. As Mike mentioned, we had a solid first quarter, with ZILRETTA's sales of $10.6 million, and preliminary net sales of $5.1 million for the month of April. I'll provide further perspective on that in the following slide.

We've historically reported the number of target accounts we've called on. This number has, and will continue to grow incrementally, as our sales reps broaden their reach. As of the end of the first quarter, 2,247 of our 4,100 target accounts, or 55%, had purchased ZILRETTA. We appreciate that this is a new metric, so for comparison, this is up from 1,837 accounts that had purchased as of December 31, 2018.

Importantly, as of March 31, just over 1,600 accounts, or 71% of accounts that previously purchased ZILRETTA, had placed at least one reorder. This is up from 1,276 accounts that had reordered ZILRETTA as of year-end 2018.

We believe this is a strong leading indicator, as it demonstrates that accounts are having good initial experience, and then place reorders. I'll discuss order volume in just a minute.

Moving to slide three, this graph provides our quarterly sales since launch, with the inclusion of the preliminary April sales. As you can see, there's been good progress since launching ZILRETTA in the fourth quarter of 2017. With a solid first quarter of this year of $10.6 million, and a strong start to the second quarter with ZILRETTA preliminary net sales of $5.1 million.

As Mike mentioned, we do not intend to provide real-time updates on a go-forward basis, but for the previously mentioned reasons, we felt that it was important to share our preliminary April sales on this call.

As we move to slide four, I'd like to start by pointing out that the remaining slides reflect purchases of ZILRETTA by accounts, which represent physician practices, clinics, and hospitals of various sides and purchasing potential. Here we present a distribution of accounts that have purchased ZILRETTA since launch, with accounts broken out into one of three groups: those that have purchased 1 to 10 units, purchased 11 to 50 units, or purchased more than 50 units.

As you can see, the majority of the approximately 2,200 accounts that have purchased the product, have bought 1 to 10 units. However, the key takeaway from this slide is that this represents an important base, and as accounts observe the clinical benefits of ZILRETTA and experience consistent and reliable reimbursement, we expect that they will increase their use of ZILRETTA. We generally see accounts begin with small initial orders, and then those orders increase in frequency and size.

In addition, at the end of the first quarter, there were more than 310 accounts that had purchased more than 50 units. One might assume that these accounts represent large practices. In fact, they represent a cross-section of accounts of varying size and across multiple geographies and are best described simply as early adopters.

Nevertheless, while these accounts are utilizing ZILRETTA at a higher rate than others, we believe that the ZILRETTA purchases to date by these early adopters represent only a fraction of their full potential. We are focused on driving increased utilization of ZILRETTA by these early adopters as well as at other accounts that have purchased less than 50 units of ZILRETTA to date.

Moving to slide five, you can clearly see the significance of these early adopter accounts on the total purchases of ZILRETTA to date. While a relatively small number of accounts have purchased more than 50 units, those accounts represent approximately 38,000 units, or more than 60% of all purchases.

Again, accounts generally move along this ZILRETTA utilization continuum from 1 to 10 units, to 11 to 50 units, and then to more than 50 units, which illustrates the real potential for ZILRETTA even with just our current customer base. We expect our customer base will continue to grow as we add new accounts, and on slide six you can see how ZILRETTA purchasing breaks out by new and existing accounts.

Over each of the last four quarters, we have added approximately 400 to 500 new purchasing accounts per quarter, and we expect to continue adding new purchasing accounts over the ensuing quarters.

Finally, moving to slide seven, here we show ZILRETTA purchases by accounts versus ZILRETTA samples that we ship to accounts on a quarterly basis. Sampling was understandably high in the early days of launch, and that decreased during 2018 as accounts gained experience with the product. In the first quarter of this year, we see an uptick in sampling as the J-code took effect on January 1, and that gave us the opportunity to gain access to certain accounts.

Nevertheless, samples still represent less than 10% of purchased product in the first quarter. Our sampling philosophy has remained the same since launch. Where our sales reps are able to make a sale, they will, but we will continue to use sampling judiciously where we believe it can serve as an accelerator for future clinical adoption.

Now, let me briefly walk through the first quarter financial results, which we included in the press release issued this afternoon, and in our 10-Q. We reported a net loss of $41.5 million for the first quarter of 2019, compared to a net loss of $41.6 million for the same period of 2018. Net sales of ZILRETTA for the first quarter of 2019 totaled $10.6 million. Cost of sales were $1.8 million and $2.7 million for the three months ended March 31, 2019, and 2018 respectively.

The first quarter 2019 net sales reflect a gross to net reduction of 7%. The gross to net reduction is primarily comprised of distributor fees, returns reserve, and mandatory government discounts and rebates, such as Medicaid, 340B institutions, and Veterans Administration and Department of Defense.

Research and development expenses were $15.4 million and $11.6 million for the three months ended March 31, 2019, and 2018, respectively. The increase in research and development expenses of $3.9 million was primarily due to an increase of $1.5 million in salary and other employee-related costs for additional headcount and stock compensation expense, as well as $1.1 million increase in pre-clinical expenses related to our portfolio expansion activities and other program costs, and an increase of $1.2 million development expenses for ZILRETTA.

Selling, general, and administrative expenses were $32.2 million and $26.9 million for the three months ended March 31, 2019, and 2018, respectively. Selling expenses were $23.8 million and $18.1 million for the three months ended March 31, 2019, and 2018, respectively. The year over year increase in selling expenses of $5.7 million was primarily due to salary and other employee-related costs, and external costs related to physician and patient marketing, and reimbursement support activities.

General and administrative expenses were $8.4 million and $8.8 million for the three months ended March 31, 2019, and 2018, respectively, which represents a decrease of $0.4 million.

Interest income was $1 million and $1.2 million for the three months ended March 31, 2019, and 2018, respectively. The decrease in interest income was primarily due to a decrease in the average investment balance.

Interest expense was $3.9 million both for the three months ended March 31, 2019, and 2018. As of March 31, 2019, the company had approximately $217.8 million in cash, cash equivalents, and marketable securities, compared with $258.8 million as of December 31, 2018. We believe that our current cash balance with the expected future sales of ZILRETTA and the ongoing prudent management of our expenses will bring us to profitability.

With that said, it is important to add that as always, we will be opportunistic as it relates to potential funding decisions, and we will do what we believe is in the best long-term interest of Flexion and our shareholders.

We expect that our operating expenses will continue to increase primarily driven by commercial activities in support of ZILRETTA, line extension clinical trials for ZILRETTA, continued development of FX201, and development activities associated with future additions to the pipeline.

...

At this point, I would ask the operator please open the line for questions.

Questions and Answers:

Operator

Thank you. That includes our prepared remarks. We will now open the call for questions. Ladies and gentlemen, if you have a question or a comment at this time, please press the * then the 1 key on your touch-tone telephone. If your question has been answered, you are to remove yourself from the queue, please press the # key.

Our first question comes from David Maris of Wells Fargo Securities.

David Maris -- Wells Fargo Securities -- Analyst

Hi. I jumped on a little bit late, so I don't know if you covered this. But on the new sales and when you were talking about the repeat users versus expansion of the use, can you just describe, of the sales increase that you expect for this year, do you think it will come from repeat users of those that have already ordered or is this expansion of the user base? And also, I don't know if you covered any -- you mentioned about non-diluted financing or alternative financing if need be. Did you mention anything about non-diluted financing related to partnerships? Thank you.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

David, I'll take a shot at the first. We expect we're going to make our target this year through growth in both components, new and repeat users. We expect both to expand, and obviously, we expect new users to become repeat users. So, we think there's a large installed base of new users that will grow, and there will be additional new users that'll get added to that, but there are also our repeat users who have had the greatest experience with the product. I would say as a result, the most reinforcing clinical experience with the product, we fully expect will continue to grow additionally.

David Arkowitz -- Chief Financial Officer

I would just add to that, if you look at the metrics statement, there are approximately 2,000 purchasing accounts that -- almost 2,000 -- that have purchased less than 50 units of ZILRETTA to date. So, there's a tremendous opportunity to really expand utilization at those accounts, and we're obviously very focused on that.

The second question was on partnerships. Was that right?

David Maris -- Wells Fargo Securities -- Analyst

Yes.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

David, this is a topic of regular discussion. We are continuing to look at the possibility of partnership outside the U.S. and will let you and the rest of the world know when anything has progressed to the point of being signed.

David Maris -- Wells Fargo Securities -- Analyst

Thank you.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Thank you.

Operator

Our next question comes from Randall Stanicky with RBC Capital Markets.

Randall Stanicky -- RBC Capital Markets -- Analyst

Great. Thanks. Mike, the April $5.1 million sales is going to get a lot of focus tomorrow and it's a helpful metric. Can you just help us calibrate that? Is there anything that we should be thinking about either being pushed out of Q1 into April or can we think of that monthly number -- and the monthly numbers in general -- as more linear in nature? And then I have a follow-up.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

We have seen steady growth from the first quarter into April, and we think this is a quite natural extension of some of the changes that we've made, and some of the new leadership -- Steve Myers and his team. And a heightened level -- an even greater level of focus and accountability in the sales organization with appropriate support from other functions. So, obviously I can't sit here and predict the future, but I'll simply say it would be surprising if we saw anything other than continued growth in the quarter.

Randall Stanicky -- RBC Capital Markets -- Analyst

Okay. So, if I was to rephrase that, generally the months aren't lumpy. We generally see month over month growth. Is that fair?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

That's a fair characterization.

David Arkowitz -- Chief Financial Officer

And Randall, this is David. Let me also chime in here. As it relates to inventory at the distributors as we talked about before, we target 1 to 3 weeks of inventory at the distributors. Those are the customers that we sell directly to. We were at that within that 1 to 3-week range at the end of the year, at the end of the first quarter of this year, and at the end of April as well. So, we obviously monitor that, we manage that, and our contracts with those distributors stipulate that they need to be within those ranges.

Randall Stanicky -- RBC Capital Markets -- Analyst

Great. That's actually really helpful. And then, Mike, the follow-up for you, we've talked about this in the past, but at some point when you look at the SG&A spend, you're remunerating it over $120 million -- all of that's not selling expense obviously, but does it make sense to start thinking about in-licensing, additional products that can be brought in with little disruption to the sales force, but add some sales leverage on top of that current commercial infrastructure? Thanks.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Yeah, Randall, it's a fair question. And the bottom line is, we are open to considering anything that makes sense to expand our commercial success. We want to balance that by ensuring that we do not in any way get distracted from the focus on ZILRETTA. We have a lot of work to do with ZILRETTA, and we're encouraged about where we're headed, but we would be entirely open to the possibility that a commercial asset could make sense, but it would have to be a compelling opportunity. I'll just say that. It would have to make sense ballistically in terms of what it would cost to in-license, whether it would cause a distraction, and what the upside potential would be for the asset. So -- yeah, please.

Randall Stanicky -- RBC Capital Markets -- Analyst

Presumably, this would be something that you would sell in the ortho channel? Is that right?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Well, that would certainly make the most amount of sense because if you weren't selling it in the ortho channel it becomes even more of a distraction for the sales force. Or you'd have to create a different sales force, which clearly would make to us, less sense. At this point in time, anyway.

Randall Stanicky -- RBC Capital Markets -- Analyst

Great. Thanks.

Operator

Thank you. Our next question comes from Elliot Wilbur with Raymond James.

Elliot Wilbur -- Raymond James and Associates -- Analyst

Thanks. Good afternoon. The first question for Mike, specifically with respect to your comments on the ongoing enrollment in the hip OA study. So, in terms of the inability to deliver in a certain subset of patients, are those -- the question is basically, you know who those patients are, so you're able to correct for that issue fairly quickly? Or was it something in certain product lots that you basically have to go out and discover exactly which patients received these particular lots?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

I'll just say this Elliot. We're highly confident that this is not a lot issue. And the reason for that is, we produce many, many lots. We have not seen this in commercial lots. Obviously, this is a clinical trial lot, but at the manufacturing site, the manufacturing process is the same. We've not seen this in any of our knee studies or our commercial knee injections. So, we're comfortable -- we're going to look for every possibility, but the likelihood this is a manufacturing issue is extraordinarily low. Realize what happened was, the patient would -- the injection would start into the hip, the injector would experience back pressure after an mL or 2 or 3 of an injection -- and this is a 5 mL injection -- and the back pressure became sufficient that it was impossible to complete the injection.

This happened without any adverse manner or any symptoms but obviously, we need to get to the root cause in order to ensure that we're able to routinely administer ZILRETTA in the hip without difficulty, that we can complete the study, file, and ultimately have a commercial product. So, there's a SWAT team in place that is looking under every possibility, visiting the site, understanding the prep technique, understanding the administration technique, realizes this is done under fluoroscopy. So, a full investigation is under way, and the study is paused until we have a root cause that can reassure us that going forward, we've solved the problem.

Elliot Wilbur -- Raymond James and Associates -- Analyst

Okay. And then, the follow-up question to Mike as well, with respect to the recently disclosed lateral data from the pivotal Phase 3, particularly thinking about the confirmation of a STAT-C benefit versus a TCA -- I think it was weeks 4 through 21 if I remember correctly. I guess those of us who've followed you for a long time and known the company for a long time -- I mean that seems like a very significant data point I guess in terms of some of the early development strategy and some of the market-based reactions, some of the data that's been -- was disclosed kind of early on. Just curious how that data point has resonated with any payors and obviously clinicians that you've talked with about that.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Elliot, just to kind of frame this for those who may be less familiar with the story than you. You've been with us for a long time. The full data set from the Phase 3 trial showed statistically significant and clinically significant separation not only from placebo but from the immediate release steroid on all osteoarthritis specific measures of pain, stiffness, function, and quality of life. It did not -- we separated very nicely from placebo on the average daily pain measure. A single question related to pain. We were numerically superior but not statistically significantly superior from the immediate-release steroid comparator.

As we thought more about this, and reflected on it, we came to appreciate that with a single question, the literature would suggest -- single question like ADP -- the literature would suggest that it's an inherently less sensitive measure, one, and it's made even further less sensitive by looking at patients who had bilateral knee pain, but by the design of the study, only got injected in one knee.

Because when you're asked about knee pain, and you might have very good relief in one knee, but the knee pain in the other knee is not affected, that not surprisingly can confound your answer. So, a very logical way to interrogate that question is to look at patients who presented in the trial with only unilateral pain. And we think of the unilateral analysis is as unmasking as cleanly as possibly the true benefit of ZILRETTA, and we see it as powerful. When you show physicians these data, they are invariably impressed, and we're in the process of sharing these data with payors also.

Elliot Wilbur -- Raymond James and Associates -- Analyst

Okay, thanks. Just one last question for the team. Anything you could share with us in terms of significant or major changes to the overall marketing game plan that have occurred in light of some of the recent changes? Have there been any?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Elliot, I think that's going to be a stay-tuned answer. I can tell you that we are aggressively reexamining all the assumptions that have gone into the marketing and sale of ZILRETTA. And we're encouraged by some potential new directions, and at the right time will be in a position to talk about them.

Elliot Wilbur -- Raymond James and Associates -- Analyst

All right. Thank you.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Thanks, Elliot.

Operator

Our next question comes from Gary Nachman with BMO Capital Markets.

Gary Nachman -- BMO Capital Markets -- Analyst

Hi, guys. The new metrics are very helpful, so thanks for providing that. Regarding the number of accounts purchasing different numbers of units, do you have a target you're trying to reach based on industry standards of what percentage of docs could end up being high-volume users? Just any analogs to compare that to?

David Arkowitz -- Chief Financial Officer

Gary, it's David. Thanks for the question. The simple answer is that we don't. So, we have 2,200 accounts, roughly speaking 2,200 accounts, out of our target 4,100 accounts that are purchasing. We are focused on really three things. That top section, those early adopters of approximately 300 accounts that are purchasing 50 units or more of increasing their utilization, because we're confident that we're just scratching the surface with them.

The accounts that are purchasing less than 50 units -- and there's almost 1,700 of those -- our focus there -- because they're really just initial users -- is to continue to drive adoption at those accounts and really incorporate ZILRETTA into their practices.

And the third piece is adding new accounts. So, 2,200 accounts with a target of 4,100. We've added 400 to 500 new purchasing accounts per quarter each of the last four quarters. We want to continue to add new accounts. So, I realize it's a little bit of a roundabout answer, but we're pretty happy with where we are. I think we've shown good progression, and we're really excited about building up on that.

Gary Nachman -- BMO Capital Markets -- Analyst

Okay. And then, the sampling, that was at 10% about of unit volume. Would you consider being even more aggressive than that to accelerate uptake? It looks like you got a positive return on that in the first quarter.

David Arkowitz -- Chief Financial Officer

So, as you can see how that progressed in 2018, clearly in the early part of 2018 it was much higher than 10%, and it ramped down over the year, consistent with what we talked about as our philosophy around sampling, which is when we can make a sale, we will. If we think that sampling can help drive initial use and familiarity, and accelerate the utilization of ZILRETTA, we will use samples to do that.

We had an uptick in the first quarter of this year really driven by the J-code and the ability to access accounts we previously didn't have the ability to get to. So, we're just going to continue to appropriately manage the samples consistent with our philosophy of if we can make a sale we will. If samples help, we will deploy them appropriately.

Gary Nachman -- BMO Capital Markets -- Analyst

Okay. And the last question for Mike, of the remaining accounts that haven't yet purchased at all, how much of those are part of the consolidated practices that you've been talking about? And maybe just give us some commentary on if you've been able to get any more traction with those practices. And if not, how you plan on doing that over the course of the year. Thanks.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Yeah, it's a good question, Gary. I would say that there are parallels with the large accounts in terms of the smaller accounts. What do I mean by that? It's a process. We have some very large accounts that are ordering, and ordering aggressively, and we have a number of accounts that are at earlier stages. And that's true for the smaller accounts.

So, the way we think about this is, if this is a continuum and many of the considerations in getting a lift in smaller accounts or 10 larger accounts, with the wrinkle -- the wrinkle that there is more administrative -- in general, a more administrative challenge. But we're pleased with the progress we're making. We're particularly pleased with the plans we have in place, and we fully expect that we're going to see continued progress in the larger accounts.

To say, if we're scratching the surface overall, we're even more superficially scratching the surface with the large accounts because the potential there is just enormous.

Gary Nachman -- BMO Capital Markets -- Analyst

Okay. Actually, I wanted to also ask you quickly -- has there been any turnover with the sales force since you announced some of the commercial changes?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

We went out of our way to say this in the press release. I actually believe that throughout the commercial organization there's a renewed sense of future and energy and passion and sense of urgency. So, there's always going to be turnover in a sales force. There certainly was no blip up in sales force and turnover. And frankly, what turnover we've had in the sales force has been almost entirely a matter of accountability and lack of performance fit. So, this is us more aggressively managing and ensuring that we have the very best most effective sales force out there.

Gary Nachman -- BMO Capital Markets -- Analyst

Okay. Thanks.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Thank you.

Operator

Our next question comes from Patrick Trucchio with Berenberg Capital Markets.

Patrick Trucchio -- Berenberg Capital Markets LLC -- Analyst

Thanks. Good evening. I have a few follow-ups from the Phase 3 OA hip pain study. Just first, did anything change from the patient enrollment or baseline characteristics from the Phase 2 SHIP study to the Phase 3 study that could have contributed to the non-safety issue in the Phase 3 study?

And then secondly, were there any issues with dosing in the SHIP study? And then I have a follow-up on 201.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Yeah, those are really excellent questions, Patrick. The simple answer to your first question is no. There were no changes in any criteria entry inclusion/exclusion criteria going from SHIP to the registration hip trial.

And the answer to your second question is, we saw at one site two patients who had -- in whom there was difficulty administering. As you might imagine, we went to extraordinary lengths to understand that. We thought we understood it adequately to initiate the hip trial, but now we've seen it -- again, it's in a handful of patients but it's across a handful of sites. And that has given us pause.

So, what we thought we understood as the root cause coming out of the SHIP study, it was only two patients out of that entire study, turned out not to be the root cause, and that's what's pushing us to take a step back and ensure we understand this completely.

Patrick Trucchio -- Berenberg Capital Markets LLC -- Analyst

Got it. And then, just regarding FX201, first, can you discuss the mechanism of IL-1Ra and its role in the pathogenesis of OA knee? And then secondly, assuming we have successful completion of the tox studies, IND filing is on schedule, when in the second half could we expect the Phase 1 trial to initiate, and how many patients will this trial enroll? How soon would you anticipate top-line data from the study?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Wow. Okay. All good questions. Let me just start. Scott is furiously writing to make sure that we don't miss any of them. First, on IL-1Ra -- this gene therapy makes IL-1Ra under the control of an inflammation sensitive promoter. So, you inject the viral particles into the knee, they're taken up by the cell's lining of the knee, the DNA strands that are contained within the viral particles ultimately end up in the nucleus, and they take the cell machinery and convert it to the production of IL-1Ra.

IL-1Ra is an interleukin-1 receptor antagonist. It's a small -- relatively small 19,000 molecular weight endogenous protein that we all have in our bodies. And as opposed to the monoclonal antibodies that might block the receptor or block one of IL-1 alpha or IL-1 beta, IL-1Ra blocks both receptors. So, it blocks at the receptor level, so both IL-1 alpha and IL-1 beta are blocked.

The data on IL-1Ra having efficacy beyond pre-clinical, because the pre-clinical data are striking. IL-1Ra is a marketed product -- Anakinra or Kineret -- and when that product, that protein, has been injected into the knees of patients who have osteoarthritis, what you see is a very nice pain relief signal. But it's transient as the protein is free to leave the knee, which it does very rapidly.

So, we're solving for persistence of therapeutic protein levels in this case with an approach which is, in essence, an on-demand anti-inflammatory effect. So, when the virus has taken up residency, and there is inflammation present, the DNA is turned on and makes IL-1Ra, suppresses the inflammation, turns off production of the protein.

We have very strong pre-clinical data on persistence of production after a single injection, very strong efficacy data pre-clinically. We're very pleased with the clinical data that provides validation. And in a large animal model pre-clinically, we see -- which is the most validated model for disease progression -- we see substantial modulation of disease progression. So, we are very enthusiastic about the potential for this product to make a difference. It will all be about the data.

When will we enroll? How many patients? And how soon can we have the data? I'm just going to continue to guide to what we said, Pat. We're going to -- assuming supportive pre-clinical tox data, we will submit this application -- this IND -- in the second half of this year. And we will enroll starting 30 days after that. We're not guiding to a more specific timeline. I would say stay tuned there because it won't be long before we have a better understanding of what the pre-clinical data are telling us, and we'll be able to provide a more granular timeline.

Patrick Trucchio -- Berenberg Capital Markets LLC -- Analyst

That's helpful. Thank you.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Thank you.

Operator

Our next question comes from Serge Belanger with Needham.

Serge Belanger -- Needham & Company -- Analyst

Hey, guys. Thanks for squeezing me in. And I apologize if these questions have been asked. So, in terms of retreatments and reimbursements, do you guys have a good read of how many patients are getting retreated? And do you see reimbursement as an issue? And has it been increasing with the publication of the [inaudible] [00:47:12] study?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Yeah, so we don't have hard numbers on retreated patients, Serge. And again, so all we have are anecdotes because it's very difficult to track at the patient level. But we have heard many stories of patients being reinjected, not just once, a second time but and a third and a fourth time. And reimbursement, to be clear, is straightforward from Medicare, and consistent. And a vast majority of commercial lines are also covered without restrictive policies for the second injection.

So, having said that, we remain committed to the removal of the LOU, because the LOU creates confusion. And there's no need for it, particularly in the face of reassuring repeat dose data that we have.

Serge Belanger -- Needham & Company -- Analyst

Gotcha. And the Phase 2 shoulder trials. How's the preparation on those coming along? And are they going to be running separately or concurrently with the frozen shoulder trial?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Yeah, so the way we're thinking about it, is that we expect to initiate both shoulder OA and frozen shoulder in the second half of this year. And we expect they will be running concurrently.

Serge Belanger -- Needham & Company -- Analyst

Okay. Thank you.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Thank you.

Operator

Our next question comes from Francois Brisebois with Laidlaw.

Francois Brisebois -- Laidlaw & Company -- Analyst

Hey, thanks for squeezing me in too. Just quickly here, I'm just wondering where -- from all the metrics that you've given, obviously so far, we're gonna have to track these, but does it change your strategy of going after the high prescribers, or just going after all the accounts? And why is that 50 units per account -- how is that number chosen -- the 50?

David Arkowitz -- Chief Financial Officer

Yeah, so this is David, Frank. How are you? Let me address the second part of your question first. So, just really given where we are in the launch, we determined that 50-unit break-point made sense. Clearly, over time, we will consider revising that and bumping that up as appropriate, but we felt it provided a good way of additional visibility insights at this point.

Francois Brisebois -- Laidlaw & Company -- Analyst

Okay. Great. And then, I guess, just quickly, I think obviously a unilateral look is very interesting to get a real feel for the drug, but can you break down what you think the population is -- the proportion of people that have unilateral pain versus bilateral?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Yeah, we can do that Frank, but I just want to start out by saying, I don't want anyone on this call to think that the unilateral data suggests that this product should only be used in the unilateral patients. Because the whole point of the analysis was that by removing patients with bilateral knee pain who were only injected unilaterally, you remove a confounding factor for understanding the effect of the drug.

So, we believe this approach was a way of more clearly understanding ZILRETTA affect without the complicating factor a patient potentially reporting on pain in the un-injected knee because they had bilateral knee pain. So, just to be clear, we certainly see this as an approach to better understanding what the data are telling us.

It turns out that -- but to answer your specific question, about 40% of an [inaudible] population will have unilateral disease and about 60% will have bilateral disease. But what I'm trying to go to great lengths to say is, we don't think that's terribly relevant because what the unilateral data tell us is the impact of the drug without confounders.

Francois Brisebois -- Laidlaw & Company -- Analyst

Okay. Great. And just quickly here, congrats -- in April $5 million is great. Can you remind us of your thoughts on seasonality here as we enter the second year?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Yeah, there is seasonality -- David is our seasonality maven, so I'll turn it over to him.

David Arkowitz -- Chief Financial Officer

Thanks, Mike. Thanks, Frank. So, I think one way to look at that is to look at HA, or hyaluronic acid, products, and how they track throughout the year just to give some flavor. So, historically with those products, you see declines of about 10% in Q1 units versus Q4. And that's due to seasonality, it's due to stocking, and it's due to contracting. I think the point though, however, is ZILRETTA's in a different place. We're still ramping, and we believe that the 11% growth in sales Q1 over Q4 was solid, so we're pleased with that.

Francois Brisebois -- Laidlaw & Company -- Analyst

Okay. Great. That's it for me. Thank you.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Thanks, Frank.

Operator

Our next question comes from Bruce Jackson with Benchmark Company.

Bruce Jackson -- Benchmark -- Analyst

Hi. Thanks for taking my question. With regard to the J-code implementation, there was some question about how quickly the physician practices could be set up on the new J-code. And I was curious to know if it's taken longer, shorter, or if the timing has been as expected? And has the availability of the new J-code helped you win new accounts?

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

I think the way to think about this, Bruce -- I'll try to answer your question. You can let me know whether I am. Once you have a permanent J-code, completing the reimbursement -- the insurance forms become much more straightforward. And more importantly, the reimbursement itself becomes more reliable and much faster. Because it's -- when you're just putting J-3304 in the form as opposed to filling a box with verbiage, that's a straightforward path. Once you have run a J-code, the claims can be electronically adjudicated which underlies the speed and consistency in reimbursement.

The way we have portrayed the impact of the J-code on improved sales performance is for a number of practices, having a permanent J-code was an absolute requirement for us to begin the sales cycle. And that is certainly well under way. Sales cycles at given institutions have varying lengths, and while we believe to see some effect of that permanent J-code, this is going to be a process that will play out quite naturally over many months.

Bruce Jackson -- Benchmark -- Analyst

Okay, that's it for me. Thank you.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Thank you.

Operator

There are no additional questions at this time. I'd like to turn the call back over to Mike for closing comments.

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

Yeah, I'll say thanks, everybody, for your time and attention. We continue to be very bullish about where we are and where we're headed. We have a lot of work to do, and we're committed to doing it, and we look forward to updating you on our next earnings call. Thanks.

...

Operator

Ladies and gentlemen, this concludes today's presentation. You may now disconnect and have a wonderful day.

Duration: 55 minutes

Call participants:

Scott Young -- Vice President of Corporate Communications & Investor Relations

Mike Clayman, M.D. -- Chief Executive Officer & Co-Founder

David Arkowitz -- Chief Financial Officer

David Maris -- Wells Fargo Securities -- Analyst

Randall Stanicky -- RBC Capital Markets -- Analyst

Elliot Wilbur -- Raymond James and Associates -- Analyst

Gary Nachman -- BMO Capital Markets -- Analyst

Patrick Trucchio -- Berenberg Capital Markets LLC -- Analyst

Serge Belanger -- Needham & Company -- Analyst

Francois Brisebois -- Laidlaw & Company -- Analyst

Bruce Jackson -- Benchmark -- Analyst

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