Ladies and gentlemen, good morning. My name is Abby, and will be your conference operator today. At this time, I would like to welcome everyone to the Seres Therapeutics Fourth Quarter 2023 Earnings Conference Call. Today's conference is being recorded and all lines have been placed on mute to prevent any background noise. After the speaker's remarks, there will be a question-and-answer session. [Operator Instructions] Thank you. And I will now turn the conference over to Rob Windsor of Investor Relations. You may begin.

Thank you and good morning. Our press release for the company's fourth quarter 2023 financial results became available at 7:00 a.m. Eastern Time this morning and can be found on the Investors and News section of the company's website. I'd like to remind you that we'll be making forward-looking statements, including the availability of cash to fund operations, the potential sales for VOWST including our ability to achieve sales targets and milestones, the timing and results of clinical studies and other statements, which are not historical facts. Actual results may differ materially. Additionally, these statements are subject to certain risks and uncertainties, which are discussed under the Risk Factors section of our recent SEC filings. Any forward-looking statements made on today's call represent our views as of today only. We may update these statements in the future, but we disclaim any obligation to do so. On today's call with prepared remarks, I'm joined by Eric Shaff, Seres' Chief Executive Officer; Dr. Terri Young, Chief Commercial and Strategy Officer; Dr. Lisa von Moltke, Chief Medical Officer; and David Arkowitz, Chief Financial Officer. In addition to that, Dr. Matthew Henn, Chief Scientific Officer, and Dr. Dave Ege, Chief Technology Officer, will also be available to address questions. With that, I'll pass it over to Eric.

Thank you, Rob, and good morning, everyone. 2023 was an historic year for Seres and an inflection point for our company and for patients. With the approval and launch of VOWST, we brought to market our first-in-class oral microbiome therapeutic for patients with recurrent C. diff infection. We are proud of the impact VOWST is having on patients, their families and the entire recurrent C. diff community. As we enter 2024, our top priorities remain: first, delivering VOWST to patients and, second, advancing the potential of microbiome therapeutics more broadly, including with our SER-155 Phase 1b readout in Allo-HSCT patients expected in Q3 of this year. Everything we do at Seres has been and always will be driven by a desire to support patients with significant unmet medical needs. It is the hope and resilience of each patient and their families that inspires us and drives us to fulfill our mission. VOWST is a perfect example of this. In VOWST, we have developed an incredible and unique option for patients who battle recurrent C. diff infection. One with a strong efficacy and safety profile as well as a convenient oral route of administration. In a particularly complex disease where historically, innovation has been difficult, today VOWST is changing lives. The US launch of VOWST has exceeded our expectations. In partnership with Nestle Health Science, we are pleased with the broad patient access received thus far with more patients gaining access to VOWST than expected. The hospital team continues its efforts to enhance hospital outflow, which we expect will continue to bear fruit into 2024. We are also seeing continued strong demand from a broad set of healthcare practitioners and across the recurrent C. diff patient pool, including utilization in patients at their first recurrence. Terri will cover our commercial metrics…

Thank you, Eric. I'm pleased to report that along with our collaborators at Nestle Health Science, we continue to make significant progress on our launch priorities in the fourth quarter, building upon earlier momentum observed with the VOWST launch. As you'll recall, our four focus areas are: scaling HCP education efforts; creating a positive customer experience; establishing payer coverage; and optimizing hospital outflow. I'll now provide an update on each of these. Our HCP education efforts emphasize the importance of microbiome restoration and recurrent CDI and the unprecedented efficacy and safety profile of VOWST. We have made significant progress in this area, supported by the promotional efforts of the Nestle field team. As a result, demand continued to grow in the fourth quarter as reported to us by Nestle Health Science. In total, between our June launch and year-end, we received 2,833 completed prescription enrollment forms for VOWST, including 1,322 in the fourth quarter alone. Of the total enrollments last year, 2015 culminated in new patient starts, including 1,082 in the fourth quarter alone. We received prescription enrollment forms from 1,330 unique prescribers between approval and year-end, nearly doubling the number of prescribers versus what we saw at the end of Q3. Approximately 65% of these prescribers of VOWST were from gastroenterology with the remainder from other specialties. Of these 1,330 HCPs who prescribe VOWST, 340 of them prescribe VOWST to more than one patient. Although as expected, the majority of 2023 utilization for VOWST was in the multiply recurrent patient group. We continue to see use in patients with their first recurrence. We expect this to continue to grow over time as HCPs gain experience with an entirely new modality and developed an understanding of the foundational and distinct role that VOWST plays in preventing recurrence. We recently completed…

Thank you, Terri. As a reminder, SER-155 is a cultivated microbiome therapeutic candidate that is designed to prevent enteric infections, including those that may harbor antibiotic resistance, and to reduce the incidence of graft-versus-host disease in patients undergoing hematopoietic stem cell transplantation. The peer-reviewed literature supports a strong connection between a disrupted GI microbiome and pathogen domination in the GI tract with the endpoint of infection graft-versus-host disease and mortality in patients undergoing Allo-HSCT. Last year, we reported promising Phase 1b Cohort 1 clinical data with SER-155 being well tolerated in highly immunocompromised HSCT patients. Our data indicated that only a single patient had enteric pathogen domination within 30 days following stem cell transplant, which was a markedly lower incident than that observed in a large reference cohort of patients. Enrollment is ongoing in Cohort 2, which incorporates a randomized, double-blinded, placebo-controlled design to further evaluate safety and engraftment as well as clinical outcomes. This portion of the study will enroll approximately 50 subjects administered either SER-155 or placebo at a 1:1 ratio. And we anticipate obtaining Cohort 2 study data in Q3 of this year. In addition to continued evaluation of the safety profile and drug pharmacology, outcomes assessed will be the ability of SER-155 to decrease rates of pathogen domination, Grade 3 or 4 acute GVHD and the incidence of GI and related bloodstream infections. We also will assess the ability of SER-155 to decrease rates of fever during neutropenia and the initiation of attendant antibiotic therapy. We believe positive data from this readout would further validate the promise of this novel therapeutic modality in addressing serious infections in medically vulnerable populations including patients with chronic liver disease, cancer neutropenia and solid organ transplant. We also believe that this approach could impact the problem of antimicrobial resistance more broadly in settings of high risk such as intensive care units. These additional opportunities have the potential to extend the utility of SER-155 and our preclinical stage pipeline and to establish a new approach in protecting immunocompromised patients from life-threatening infections and related clinical events. With that, I'll turn the call over to David for an update on financials.

Thanks, Lisa, and good morning. I'd like to discuss our financial performance for the fourth quarter, starting with VOWST. Let me first remind everyone that Seres has not recognized VOWST net sales in its financial statements, but instead, we share equally with Nestle, the commercial profits and losses, and we record our share in collaboration, profit and loss sharing related party. VOWST profits and losses are determined based on VOWST net sales, cost of goods sold and sales and marketing expenses. Consistent with our prerelease in January, net sales of VOWST for the fourth quarter were $10.4 million and based on 673 units of VOWST sold during the period to specialty pharmacies and distributors. The net sales reflect estimated gross to net reductions of approximately 11%. We estimate that at the end of last year, there was approximately two weeks of VOWST inventory in the channel at specialty pharmacies. Seres supplies VOWST inventory to Nestle, and we received payments from Nestle related to their VOWST supply purchases to meet market demand. During the fourth quarter, Nestle purchased approximately $9 million of valve supply from us, and we received approximately $17 million in payments from Nestle related to prior quarter purchases. The total VOWST loss in the fourth quarter was $20.5 million, and our share of that was $10.3 million. The fourth quarter VOWST collaboration expenses, meaning COGS and sales and marketing expenses for VOWST increased from the prior quarter. This increase was due to higher COGS given the variability of manufacturing costs for VOWST produced prior to approval as well as some prior period adjustments and higher sales and marketing expenses due to increased free goods and the initiation and ramp-up of some key marketing activities. For the fourth quarter, we also recognized as collaboration profit or loss sharing related…

Thank you, David, and thank you again for all your contributions to Seres. We wish you well in your retirement. Before opening the call up to Q&A, I would like to express how proud I am of the team at Seres and the team at Nestle for bringing a first-in-class oral therapy to the market. 2023 was truly a trailblazer year for Seres as well as for microbiome therapeutics. As we look forward into 2024, I'm excited about the continued success of VOWST, as well as the possibilities with SER-155. With that, we will conclude our remarks and open the line up to questions.

[Operator Instructions] And we'll take our first question from Jeff Jones with Oppenheimer. Your line is open.

Thank you. Can you hear me?

Yes, we can, Jeff. Good morning.

Great. Thanks, Eric. I guess can you speak to the main drivers of what looks to be about a $170 million spend in 2024? I know we've spoken to your second manufacturing site in the past? And then any discussions you might be having with Nestle regarding the now about 10 months runway?

Yeah. Maybe I can ask David to start on the parameters of investment and then I can take the second question on our partners.

Yeah. I would just say, Jeff, at a high level, about half of that relates to R&D. And a big chunk of that R&D spend relates to really ramping up our upcoming manufacturing facility in Bacthera, so you're talking about -- we're talking about tech transfer and really driving towards approval of that facility. So that's driving a lot of the spend. Keep in mind that we are also operating -- we will be operating Bacthera and our existing CMO simultaneously in 2024. As we get into 2025, that will drop off. We will move to primarily one CMO, so you'll see some of that spend dissipate. And then we've got G&A expenditures to operate as a public company as well as our share of the VOWST collaboration profit and loss.

Maybe I can just add, Jeff, to the second part of the question. In general, we are highly focused on cash, on runway, on investments and ways in which we can continue to support the company. And certainly, you saw at the end of last year, action from us with the restructuring, 41% reduction in headcount. We estimate between $75 million to $85 million reduction in 2024 spend. So our three priorities for this year are, one, supporting the launch of VOWST. Two, driving towards a SER-155 readout. And three, supporting the company, both through augmenting the balance sheet, reducing spend and looking actively at ways in which we can continue to support our operations. I would say from our partners' perspective, I think we both are pleased with the launch to date. We know that VOWST is important to Nestle. We know that there's real synergy between Zenpep and VOWST and I won't go forward than that. But obviously, we care deeply about supporting the company, and we're actively working to try to put ourselves in the best position to serve patients in the long term.

Just one quick follow-up on that and the work at Bacthera, which involves manufacturing batches. Any chance that some of those batches can be used commercially? And so that spend there actually goes to saleable product?

Yes, I can comment on Bacthera, but maybe we've got Dave here who can comment on the specific question around the batches.

Hi, good morning. Yes, the simple answer is that is correct. Like it's anticipated that the PPQ batches for validation will be salable and ultimately would go into commercial supply.

And I would just add, we continue to make progress with Bacthera in supporting continued augmentation of our capacity. And we're working with them as well to think about ways in which we can continue to support both companies and our relationship moving forward.

Great. Appreciate it. I’ll jump back into the queue guys.

Thanks, Jeff.

We will take our next question from John Newman with Canaccord. Your line is open.

Hi guys, good morning. Great progress about the hard work on the VOWST launch, very good. Obviously, appreciating that you are currently very focused on commercialization, excuse me, of VOWST, as well as the current SER-155 Phase 1b study, I'm just curious where do you see future opportunities for the drug technology itself?

Yeah, John, good morning, and thank you for the question. Maybe I can start now and I'll invite Matt, who's here to provide some commentary as well. But I think I'll start with your question led off, which is we are focused. Our priorities for 2024 are VOWST launch, 155 and supporting the financial condition of the company. So we are deeply committed to the strict allocation of capital along those key priorities and focus, I think, is the name of the game for us in the short term. That said, that doesn't mean that we can't -- also can't be excited about what could potentially be opened up with a positive readout in the 155 study. So we are particularly excited about that. Maybe I can invite Matt to comment further.

Yeah, John. I mean, thinking about that kind of potential, as Eric said, that could be opened up. Really, when you think about the past decade, there's really just been an incredible explosion in the research that's defined a really substantial role for the microbiome in both states of disease, states of health. And importantly, we've learned a tremendous amount mechanistically about how that happens. So -- and this is best understood in the context of the gastrointestinal track which is where Seres is focused. Our research to date and our programs to date. And there's a role to be played around infections, as we've talked about, priming both the adaptive and the immune systems, general metabolism and quite frankly, data supporting gut brain access, et cetera. But I would like to think about the development of microbiome therapeutics and the various strategies that we can pursue here. I think of it similar to gene therapy. It's early. There's really sound science. There's really a lot of potential, but translation takes some time and to succeed here, people need to build platforms that can really kind of get at the heart of scientifically and mechanistically what's happening and as well, strategically broaden our pipeline. And in short, Seres has built such a platform and we're pursuing such a pipeline strategy, right? We have the ability to go from early-stage discovery all the way through to manufacturing of these therapeutics. We can interrogate a very, very high resolution micro, micro, micro post interactions that allows us to really get at specific pathway specific targets that we can target. And then our portfolio strategy has been building incrementally. So VOWST provides us a very strong proof of concept around the concept to be able to address infections in the gut. And our SER-155 program is building on that knowledge to go after a broader set of pathogens as well as leverage critical insights we have from a preclinical and clinical standpoint on how we can have an impact on preventing infections and colonization of various pathogens, how we can actually induce immune tolerance in the gastrointestinal track as well as actually look at the epithelial barrier and have impacts there. So this is all built into this 155 program. And as you heard on the call today, that -- we see that really just as the initial point for that expansion, where we can move into additional medically-compromised patients where we see disruptive microbiome, people at risk for these same kinds of factors that include cancer neutropenia, solid organ transplant, liver -- chronic liver disease and really that problem of AMR more broadly in the ICU. So we see really broad potential, and we're excited to get to the next point to sort of enable us to be able to pursue that. But right now, we're focused on VOWST and our 155 program.

Great. Thank you.

Thanks for the question, John.

And we will take our next question from Tess Romero with JPMorgan. Your line is open.

Hello, good morning guys. Thanks so much for taking our question. So how should we think about the sales trajectory in 2024 for VOWST? And specifically, what is the right way to forecast percent of free drug over the course of 2024, given the patient affordability challenges you cited? And then second question is, can you clarify what you mean by the strengthened promotional campaigns and expanded reach of digital promotion by Nestle and what this means with respect to expected pull-through to the launch?

Yeah, Tess, thanks for the questions, and good morning. Let me invite Terri to comment on both questions. I would just start by saying Terri spent most of last week with the Nestle commercial group and leadership. So I think it's a good time to ask that question and provide some visibility as to how we look at 2024 and the trends that are important.

Yeah. So in 2024, we're obviously, as with any launch, looking for continued growth, breadth and depth of prescribing specifically, right? We're seeing good access. We seek to preserve that. So it's really about HCP trial and adoption in 2024. And I'll touch on predrug last. Digital promotion is actually a key tactic that it's important for a brand to leverage after you've educated your top prescribers and KOLs. So we've spent with Nestle the first months after the launch, making sure that we had deep conversations, deep education efforts with the top prescribers, activating the high-volume prescribers. And from there, we're really seeking to enhance breadth of trial. And so you can do that leveraging the sales force that we have, but we really aim to go broader than that. And that's the role of digital promotions. So you tend to scale that anywhere from four to six months after approval and launch. And so that's what we've done. So we had a new campaign that launched and was rolled out to the representatives in October of last year, right around IDWeek and that campaign was significantly scaled digitally to HCPs. We also scaled patient promotion. You typically do that six months after a launch because you don't want to send activating your patients into a physician and have the patient be the first source of awareness about a new product. So we want to make sure that physicians are aware of the new product before we turn patients on and send them in. So all of that is in the rearview mirror now, and it's about those campaigns delivering the additional breadth of prescribing and subsequent depth that we would expect because we know once physicians try VOWST, they're having a good experience and they're willing to try…

Thank you.

And we will take our next question from Peyton Bohnsack with TD Cowen. Your line is open.

Hey, good morning guys and thanks for taking our question. I guess to kind of build up on the previous question, talking about launch trajectory. I was wondering if you could give us a little more detail about the potential penetration in the first rCDI population. And are there any specific strategies that you guys can do to kind of build further into that population? Or is it just mostly a position education effort? And then I have a follow up.

Sure. Pete, why don't I give the first one to Terri.

Sure. So absolutely, the strategy that we're taking is to definitely accelerate utilization into the earlier lines of therapy within rCDI, right? So there are a number of ways to do that. One is achieving breadth, and I went into some depth about the breadth there with Tess a minute ago. But digital promotion is really a way that you can reach deeper into the prescriber base even into primary care, we're -- not a lot, but many of the first recurrent patients are treated. So the breadth of -- prescribing the breadth of promotion, the breadth of awareness is really important to achieve and that should go a long way toward unlocking additional use in that population. But we do see that our core set of prescribers actually see and are choosing VOWST for these patients. And as they see VOWST work, they see that it's easy to use. They will broaden their use. They have -- they told us that they would do that before launch. We're already seeing that with the depth and repeat prescribing that we're observing and observed in 2023. So it's continuing to have the sales representatives on the Nestle side, encouraged their physicians to move the product earlier based on the amazing results that they're seeing in the patients that they initially chose. So it's a mixed bag of tactics, but we're very focused there with Nestle this year.

Positive experience could have a cascading effect, and that's...

Absolutely, big accelerator.

Great. And I guess you kind of actually touched on my second question, which was -- are you really seeing a lot of these first rCDI patients that you have not been treated? Are these largely coming from GIs or you're like targeted group of high prescribers? Or are these single people that are maybe not as high prescribing or principal care providers or infectious disease stock? And any additional details that we get on that would be much appreciated.

Yeah, it's actually been one of the most interesting aspects of the launch and one way that the launch has exceeded our expectations is the breadth of use that we're seeing. Across physicians, across physicians the field representatives are calling on, also physicians that they're not. And we're seeing within the physician user pool a large variety of where physicians are choosing to use it first. So we're not really seeing a pattern interestingly, which I think is highly encouraging for the launch. Every physician is basically choosing the patient that they think is at risk based on the patient that happens to be in front of them and their office at the moment, and we are seeing the utilization in first recurrence as well as in multiply recurrent. So we feel good about the patterns that we are seeing and that there is not a pattern other than the doctors choosing a high-risk patient, irrespective of number of recurrences.

Great. Thanks for the additional color. Thank you for the additional color and for letting me ask a follow-up.

Thanks, Peyton. Thanks for the question.

And we will take our next question from Chris Shibutani with Goldman Sachs. Your line is open.

Great. Good morning. I wanted to ask about SER-155 and how we should be thinking about the decision tree that you'll have when the data is reported in the third quarter, in particular, when you think about kind of scale and the budget that would be required to further advance in the event of positive data, how are you thinking about your capacity to fund this? Is this something where you're currently contemplating potential partnerships? And then secondly, I think you have access to a tranche of a loan from Oaktree. Can you help us understand any of the mechanics that would be involved so that we can understand how that might be a lever to also help support financing of continued success with SER-155 if positive data comes in the third quarter. Thank you.

Yeah, Chris, good morning, and thanks for the two questions. What I'd like to do is maybe invite Lisa to comment a little bit on what we are expecting in the 155 readout or what we hope for. I will say as it relates to resourcing Chris, what we said at the time of the restructuring last year was that we would pursue 155 to the clinical readout with the -- both the clinical and microbiome analysis that comes with it. But that we were gaining investment beyond that to the readout itself. So our expectation is that 155 will basically stand on its own. If it's successful, we think there are multiple ways in which we can support it and it could bring additional resources into the company. But if it's not, then we're not going to pursue it without being able to fund it, obviously. So maybe I can ask Lisa to comment on that and then David and I can take the question on Oaktree.

Yeah. Just a reminder that this study offers us the possibility to go in a number of different directions, depending on the results. We could have a play in acute GvHD as well as on the infection side where we think there are a number of different end points that could show us a way forward. And so we'd be looking to -- most likely choose a particular route, either the infection side or the acute GvHD side, and then hopefully do a very focused and accelerated path forward. With the kind of results that we would be hoping to see, we would not expect that this would be a large, long trial that would be -- we have to resource.

Yes. So we will follow the data and the resourcing piece we hit, I would just also mention as a reminder that we did receive Fast Track Designation. So we think that how we interact with the agency and thinking about the next study that Lisa mentioned, I think should be augmented as well. Maybe I can ask David to comment on the Oaktree question, I might add a couple of comments on top.

Great. Thanks, Eric. So when we established the debt facility with Oaktree now almost a year ago, we set it up in a way that it would provide access to capital for us, not just initially, but also as the company grew and as the company evolved. There's actually two $45 million tranches that are available to us. Tranche B, which is based on six-month trailing VOWST sales of at least $35 million. And then tranche C, which is based on 12-month trailing sales of at least $120 million.

And I would just reiterate again, Chris, that -- as we think about those potential sources of capital, I kind of think about that exclusive of 155. I think that 155 will stand on its own with positive results. But we think about the Oaktree somewhat differently.

Great. And if I could just ask a follow-up on 155 amongst the different paths. Is there one that scientifically, you think you have the highest probability of success or at least you have a hypothesis that would be the case? And then is there one that may be from a regulatory progress standpoint might be a shorter duration and more sort of focused concise efficient from a cost standpoint path. I ask those two questions in that way because, hopefully, they're related, but may not be the same. And again, looking for your perspective.

No, it's a great -- thanks for the question. Maybe I'll ask Matt to start and I might suggest that we start with the first cohort data that we saw which is really encouraging to us. And then maybe Lisa can comment on her perspective as well as the regulatory landscape.

Yeah, right. So Chris, as a reminder, SER-155 is really designed to target two specific areas. One is the domination of pathogens and the incidence of that in the gastrointestinal tract, particularly of Enterococcus and a couple of Enterobacteriaceae species that are particularly problematic in this patient population. And the second is to improve immune tolerance in the gastrointestinal tract to have an impact on graft-versus-host disease, particularly in the GI where it's most prominent in these particular patients. There is a strong literature and a deep literature that connects in particular, the disruption of the microbiome and that increased incidence in pathogen domination. To these various downstream clinical sequela that we're looking at that Lisa talked about earlier, enteric infections, associated bloodstream infections and in particularly more severe forms of graft-versus-host disease. So we believe actually both endpoints in terms of thinking about infections and the various ways we're looking at that as well as graft-versus-host disease are very well founded, and we've substantial preclinical and clinical data that support our drugs can have an impact there. And I think most significantly is the cohort 1 data that we released last year, where we saw a substantial reduction in that incidence of pathogen domination in the gastrointestinal track relative to control court. Remember, we saw a single patient having one of these pathogen overgrowth events where we would have expected that to be of substantially higher in the order of about 60-plus percent of patients having such. So with that, I'll turn it over to Lisa.

Sure. So I would just say that the -- both areas, the GvHD as well as the infection protection area, huge interest to both the medical community and the regulators. GvHD, we now have a guidance from the regulatory folks at FDA. So we know what they would want there. I think the infection protection side has numerous programs coming out of the agency to encourage development work there. It obviously is adjacent to the C. diff area in terms of our results and our ability to show results there. And we could imagine a number of endpoints lining up from high -- very high frequency events such as neutropenia and fever, and all the way down to the incidence of particular infections such as the GI tract. All of those lining up would make a very powerful story. And the agency has talked about that before with regard to primary and secondary endpoints lining up and the strength that, that gives an approach.

Great. Appreciate the additional thoughts.

But you can see I have a little bit of a preference.

Yeah. No, that comes through. Thank you so much.

Thanks for the question, Chris.

And we will take our final question from Keay Nakae with Chardan. Your line is open.

Yes, thank you. So having implemented the head count reduction late last year, to what extent -- and again, I know you're very focused on the launch of VOWST, but to what extent, if any, at this point, do you feel like the current headcount and operating plan is in any way constraining what you'd like to do on the marketing side for VOWST? Thanks.

Yeah, good morning, and thanks for the question. I would say that our headcount reductions constrained a number of things, in particular, on the R&D side of our portfolio. But from a marketing investment, we work with Nestle, we have contractual parameters by which the budget is set and executed against. So we don't believe the headcount reduction has an impact on the investment to support the VOWST launch.

Okay. Thanks.

Sure.

And ladies and gentlemen, there are no further questions at this time. So I will now turn the call back to Mr. Eric Shaff for closing remarks.

Thank you, and thanks to everyone for joining us this morning. We look forward to keeping you updated on our progress. Hope you have a great morning, great day and a great week. We'll talk soon. Thank you.

And ladies and gentlemen, this concludes today's call, and we thank you for your participation. You may now disconnect.