Ladies and gentlemen, thank you for standing by and welcome to the Seres Therapeutics First Quarter 2021 Earnings Conference Call. After the speaker presentation, there will be a question-and-answer session. Please be advised that this conference call is being recorded. I would now like to hand the conference over to your speaker today, Dr.

Carlo Tanzi of Investor Relations. Carlo, please go ahead. .

Thank you and good morning. Our press release with the company's first quarter 2021 financial results and the business update became available at 7:00 AM Eastern Time this morning and can be found on the investors and media section of the company's website.

I'd like to remind you that we'll be making forward-looking statements relating to the timing, enrollment and results of our clinical studies and anticipated safety profile of our products, regulatory approval and the promise and potential impact of any of our microbiome therapeutics. Additional 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 President and Chief Executive Officer, Eric Shaff; Chief Medical Officer, Dr. Lisa von Moltke; Chief Scientific Officer Dr. Matthew Henn; and Chief Technology Officer Dr. David Ege. Dr. Terri Young, Chief Commercial and Strategy Officer, will also be available for Q&A.

And with that, I'll pass the call off to Eric. .

Thank you, Carlo and good morning, everyone. Seres entered 2021 building on strong momentum created in 2020, catalyzed by the success of our SER-109 program. We have continued to make progress across multiple functions within the company, including clinical, regulatory, manufacturing and commercial.

Collectively, these efforts bring us closer to our goal of translating our scientific microbiome insights into an entirely new class of medicines to treat serious human diseases. Since reporting positive data from our Phase 3 SER-109 ECOSPOR III study in patients with recurrent C. diff infection.

Our focus has centered around taking the necessary steps to enable a high-quality BLA submission and following potential FDA approval, preparing for a successful commercial launch. Our immediate priority has been to complete the required SER-109 safety database through our ongoing open-label study.

We are very pleased with the pace of the study's enrollment and we are -- and we now expect to achieve the full 300-patient target during the third quarter of this year. Our organization is also preparing for a successful commercial launch.

We believe that a substantial commercial opportunity exists for SER-109, the recurrency of this population includes approximately 170,000 patients in the U.S. Our medical education and awareness efforts continue and we have recently begun to deploy our medical science liaisons.

We are encouraged by the positive reception we are receiving from the medical community, which speaks to the high level of unmet need in the category. The importance of medical education is critical, especially when introducing a new approach and we feel we are already making important inroads.

We are also continuing supportive market assessment work, including primary research with physicians and payers to support launch campaign development and pricing and reimbursement decisions.

We look forward to continuing to engage with patient groups, physicians and payers to educate the market about the substantial value of our microbiome therapeutic approach. In addition to SER-109, we are advancing a pipeline of investigational microbiome therapeutics led by SER-287 our Phase 2b candidate for ulcerative colitis.

SER-287 has the potential to transform the management of this disease, intended to provide an effective treatment approach that is well tolerated, with what we expect will be a favorable safety profile.

As we announced last quarter, the SER-287 Phase 2b study has achieved target enrollment and we look forward to reporting top line of clinical data in mid-year with additional mechanistic results in the second half of the year.

SER-287 has the potential to provide UC patients with a meaningful new therapy and we also believe that this investigational therapy could be a very meaningful value driver for the company. We are eagerly looking forward to the Phase 2b study results in mid-year.

With that, I'll now turn the call over to Lisa for a more detailed overview of our clinical programs..

Thanks Eric and good morning everyone. I'll begin with our SER-109 program. SER-109 is a first-in-class investigational microbiome therapeutic administered orally following antibiotics and designed to reduce recurrence of C. difficile infection. SER-109 is comprised of purified firm acute bacterial spores.

This class of bacteria was specifically selected based on the impact they have on the growth and survival of C. difficile and their broader functional importance in the microbiome of individuals without disease.

Our previously reported ECOSPOR III Phase III study results demonstrated that SER-109 met the study's primary efficacy endpoints in patients with recurrent C. difficile infection showing a substantial absolute reduction in recurrent infection compared to placebo at eight weeks post-treatment which was the study's primary endpoint.

The results demonstrated a remarkable sustained clinical response rate of approximately 88% at eight weeks post-treatment. The primary endpoint showed an absolute reduction of recurrence of CDI of 27% compared to placebo at eight weeks post-treatment and the relative risk reduction of 68%.

Study results show that SER-109 administration resulted in similar efficacy when examined by group stratified by age or by the prior antibiotic therapy. Additionally the Phase III data demonstrate that SER-109 efficacy is maintained over the duration of the 24-week study.

We are very pleased with our SER-109 clinical data and we believe that the clinical profile observed is highly differentiated from other therapeutics in development for a recurrent CDI.

In addition to the differentiated clinical profile Seres employees various manufacturing processes to support patient's safety, including steps designed to inactivate and remove vegetative bacteria, parasites and viruses.

We believe these processes help to minimize risks for patients even from emerging infectious diseases where diagnostic assays may not yet be available. We believe that our approach provides SER-109 with distinct safety advantages compared to minimally processed investigational microbiome approaches.

From a tolerability perspective we observed a highly favorable safety profile with SER-109 adverse events being similar to placebo. We are working toward publishing the remarkable SER-109 Phase III study results in a leading journal.

Overall, we believe our SER-109 Phase III data represent a substantial advancement over the standard of care with the potential to fundamentally transform how CDI is managed.

Furthermore, we believe that SER-109 has the potential to meaningfully improve outcomes for patients with recurrent CDI, a disease that results in the death of over 20000 people in the US each year.

From a regulatory perspective the SER-109 ECOSPOR III study results far exceeded the efficacy threshold communicated to us by the FDA for the study to serve as a single pivotal trial. As a result, we expect this single study to provide the efficacy basis for SER-109 BLA filing.

The FDA has also communicated to us that at least 300 patients will be required for our SER-109 safety database to support a BLA and product approval. To this end, we continue to enroll our SER-109 open-label study in patients with recurrent CDI. And as Eric mentioned we have made excellent recent progress with this study.

We have added dozens of new clinical sites across the US and Canada beyond those included in the Phase III. And we have seen substantial physician enthusiasm for SER-109. We have also recently modified the open-label study protocol to enable flexibility in the testing methods used to diagnose patients entering into the study.

We expect this change to facilitate patient participation in the study and access to SER-109. I'm happy to report that SER-109 open-label study is now over 2/3 enrolled and based on recent trends, we expect to achieve target enrollment during the third quarter of this year.

The FDA has requested that six months of safety follow-up be included in the safety database. Completion of the safety database will support a BLA filing and potentially enable SER-109 to become the first ever FDA-approved microbiome therapeutic.

Now, while the specifics of any potential product label would of course depend on discussions with the FDA during BLA review, our expectation is that SER-109 could be indicated for the broad recurrent CDI patient population. A group estimated to include approximately 170,000 individuals in the US.

Also, we would not expect specific labeling requirements regarding diagnostic approach as this is typically left to the discretion of the treating physician and reflects local practice factors. Consistent with these expectations the SER-109 open-label study includes enrollment of the broad recurrent CDI patient population.

Next, let's turn to our ongoing SER-287 Phase 2b study in patients with mild-to-moderate ulcerative colitis. SER-287 is an orally administered drug candidate comprised of commensal bacterial spores isolated from the healthy human gastrointestinal tract.

Our objective with SER-287 is to develop a first-in-class microbiome therapeutic that modulates the microbiome and the microbiome associated metabolites to treat ulcerative colitis. Several lines of evidence suggest that the gastrointestinal microbiome may act as an important underlying cause of inflammation in patients with ulcerative colitis.

SER-287 is designed to modulate the microbiome in these patients and potentially provide a much needed non-immunosuppressive treatment option for UC. Furthermore, because of the safety profile that we expect from our approach, we believe that SER-287 has the potential to also be used in combination with other approved agents.

Data from our completed Phase 1b study demonstrated that SER-287 administration was associated with a favorable safety profile, as well as high rates of clinical remission endoscopic improvement and modulation of the gastrointestinal microbiome.

These results and data supporting the underlying mechanisms of action were highlighted at the cover article in the January 2021 print edition of the peer reviewed journal Gastroenterology. We are currently running a SER-287 Phase 2b study termed ECO-RESET. This is a randomized placebo-controlled three-arm induction trial.

The study is fully enrolled with 203 patients with active mild-to-moderate ulcerative colitis who have had an inadequate response to prior therapy.

In arm A patients receive a short course of vancomycin preconditioning followed by 10 weeks of the same daily regimen that was used in the arm of the previous 1b study that showed the highest clinical remission rate.

In arm B patients receive vancomycin preconditioning followed by two weeks of the same SER-287 daily regimen used in RNA followed by eight weeks of a lower dose. In arm C patients receive placebo. We expect topline clinical results from ECO-RESET in mid-2021.

As a well-designed and meaningfully sized Phase 2b study we expect this to be a data-rich study readout that will enable us to make well informed decisions regarding further development.

In addition, we expect to obtain a great deal of information about the mechanism of our microbiome drugs in UC patients that will continue to inform our UC franchise and microbiome targets and other indications.

Clinically, our primary objective in the Phase 2b study is to demonstrate that SER-287 results in a significantly higher proportion of patients achieving clinical remission than those administered placebo.

In evaluating our upcoming data, we plan to carefully examine the overall rates of remission across the study cohorts and we will also examine the impact of SER-287 on important secondary measures such as endoscopic improvement.

We believe that the safety of our microbiome therapeutic approach based on commensal healthy bacteria is a major advantage and anticipate that the safety profile of SER-287 will be highly favorable, especially as compared with current treatments which are often immunosuppressive and expose patients to significant risks.

We expect that, if we are able to achieve our target clinical profile showing clear efficacy and favorable safety and with an orally administered therapy SER-287 could represent a highly attractive new medicine with the potential to transform the management of UC.

SER-287 could have the potential to provide mild-to-moderate UC patients, representing the majority of all UC patients with a novel and effective treatment option that is not immunosuppressive.

The SER-287 study will also be important to inform a broader, multi-product and longer-term efforts to develop transformative new medicines for inflammatory bowel disease and more broadly for modulating host immunity. We expect to gain important insights from our pending Phase 2b clinical data and for microbiome biomarker data coming later this year.

Both will inform the further development of SER-287 as well as that of SER-301 and other future compositions designed to modulate host inflammation and immune pathway signaling. With that, I'll now turn the call over to Matt. .

Thank you Lisa and good morning everyone.

Seres continues to invest and focus on our reverse translational discovery and development platforms that can delineate at high-resolution microbiome biomarkers from human clinical data and integrate these data with preclinical assessments using human cell-based assays in in-vitro, ex-vivo and in-vivo disease models to evaluate drug mechanisms of action and to design consortia of bacteria with specific pharmacological properties.

Our drugs are designed to target multiple disease-relevant pathways. We reported earlier this year at the Keystone Microbiome Symposium on SER-109 Phase 3 predefined microbiome read outs that confirmed the drug candidate's mechanisms of action.

The SER-109 Phase 3 study data demonstrated that the bacterial species in the drug rapidly engraft into the gastrointestinal tract. Engraftment was observed as early as one week post-treatment and found to be durable through 24 weeks.

The presence of SER-109 bacteria was significantly greater in subjects that received SER-109 versus placebo and all differences were maintained in all subpopulation analysis. SER-109 administration also rapidly shifted the gastrointestinal metabolic landscape.

As an example, there was a significant decrease in primary bile acids and an increase in secondary bile acids providing a mechanistic basis for both the inhibition of C. difficile spore germination and vegetative growth. Notably in early time point sample, C.

difficile and other bacterial passages known to harbor antibiotic-resistant genes were significantly more prevalent in placebo-treated subjects. These data confirm observations from Seres prior trials that SER-109 resulted in a reduction of other clinically relevant bacterial pathogens.

The detailed mechanistic learnings we have obtained from SER-109 combined with our ability to link these learnings to clinical outcomes and confirm observation human subject in the non-clinical setting to demonstrate causality have proven immensely beneficial and we continue to apply this knowledge to the design of future planned microbiome therapeutic compositions.

Moving now to our SER-301 program. SER-301 is the next-generation orally dosed rationally designed cultivated microbiome therapeutic candidate for the treatment of ulcerative colitis.

The consortia of bacteria in SER-301 is designed to modify the microbiome and microbe-associated metabolites in the gastrointestinal tract to reduce the presence of pro-inflammatory bacteria and modulate pathways going to gastrointestinal inflammation and epithelial barrier integrity in patients with ulcerative colitis.

SER-301 is designed using Seres reverse translation discovery and development platforms. The design incorporated learnings from our SER-287, Phase 1b study related to the bacterial species and the microbiome functional signatures associated with clinical efficacy.

Additionally, the design took insights related to the engraftment dynamics of different bacteria and also the association of specific bacteria with the modulation of inflammatory and immune pathways in human subjects that have been observed across our broader clinical portfolio and confirmed using our non-clinical human cell-based assays in in-vivo models.

As a result the unique composition of SER-301 was designed to optimize drug species engraftment and the pharmacological properties that our clinical and preclinical research have identified as potentially important microbiome drivers of a treatment effect.

We expect that we will continue to learn more about the activity of our microbiome therapeutic approach in ulcerative colitis from the SER-287 Phase 2 results that these translational learnings will continue to inform our future development efforts in this indication and in biologically adjacent disease indications.

We are currently enrolling a SER-301 Phase 1b study in adults with mild-to-moderate ulcerative colitis. This study is being conducted in Australia and New Zealand for the target enrollment of 65 patients in total.

The objectives for this study are to evaluate drug safety and pharmacokinetics and to evaluate clinical remission and other measures of efficacy as secondary endpoints. Moving now to SER-155.

SER-155 is an orally-dosed rationally-designed cultivated microbiome therapeutic candidate designed to decrease the incidence of gastrointestinal bacterial infection, bacteremia and graft versus host disease immunocompromised patients receiving allogeneic hematopoietic stem cell transplantation.

SER-155 builds on our expertise in both infectious disease and immunology and is designed to both prevent bacterial infections, particularly those that harbor antibiotic-resistant genes bacteremia and the onset of graft versus host disease. The SER-155 program is supported by a CARB-X grant that provides financial and operational support.

We've made excellent recent progress towards advancing SER-155 into the clinic in collaboration with our partners at Memorial Sloan Kettering Cancer Center. We expect to initiate clinical development later this quarter. Turning now to our earlier stage pipeline. We are evaluating a number of potential new indications for our microbiome therapeutics.

Our clinical programs and our reverse translation discovery platforms continue to provide meaningful insights and knowledge into the underlying mechanisms, by which micros in the GI tracts, engage pathogenic bacteria and human cells and tissues to impact disease.

Moreover, advances in Seres microbial cultivation and bioprocessing know-how and commercial scale GMP capabilities, continue to advance and broaden access to the diversity of microbes in the human GI that can be harnessed in potential new product candidates and development programs. I'll now turn the call over to Dr.

Dave Ege, our Chief Technology Officer, to provide more color on Seres' differentiated manufacturing capabilities..

Thank you, Matt, and good morning, everyone. We believe that Seres' GMP manufacturing and quality control platforms are important core capabilities that provide our company with meaningful competitive advantage. First and foremost is our differentiated product safety profile.

Pathogen in activation and clearance steps are incorporated into the manufacturing process and validated, coupled with rigorous GMP product testing using proprietary assays. These measures are designed to maximize patient safety including against emerging pathogens such as SARS-CoV-2.

Second, Seres has developed considerable proprietary expertise and know-how regarding how to efficiently produce and test anaerobic bacterial strains in both vegetative and spore formulations.

Our differentiated strategies to pursue both donor-derived and cultivated rationally design complex consortia has been highly synergistic and gives us a substantial technical advantage in how we advance our pipeline.

We believe these investments in manufacturing and quality control over many years now put Seres in a strong position to reliably support late-stage development of our pipeline and commercial supply as well as our early stage programs. And with that, I'll now turn it back to Eric..

first, achieving full enrollment in our SER-109 open-label study during the third quarter of this year; continued progress executing on SER-109 pre-commercial readiness including our market education efforts; topline clinical results from the SER-287 Phase 2b study midyear; and continued enrollment of our SER-301 study and the advancements of our SER-155 study into clinical development.

Our organization also continues to work to extend our microbiome therapeutic leadership position. With SER-109, we expect to pave the way towards achieving the first ever approved microbiome therapy.

Along with what we believe to be SER-109's best-in-class clinical profile, we expect to have a substantial first-mover advantage that will support successful commercialization.

We are also continuing to make progress advancing our pipeline and we expect that in the coming years, we will be bringing additional new microbiome therapeutics into late-stage development and hopefully to patients seeking new treatment options.

Finally, we are devoting meaningful resources to strengthen our already field leading core capabilities, including those focused on microbiome drug discovery, as well as with our advanced microbiome manufacturing capabilities.

Supported by the solid foundation, we believe that Seres is well positioned to continue to drive the microbiome therapeutic field forward.

Before I conclude, I'd like to mention that as announced in our press release this morning, we will be holding a Virtual Investor Event on June 21 focused on ulcerative colitis including a detailed review of our SER-287 and SER-301 programs.

This should be a very interesting program that will include one of the leading academic experts working in the area and we hope that you'll be joining us. With that operator, we'll turn the call over now to questions..

Thank you. [Operator Instructions] Your first question comes from Mark Breidenbach from Oppenheimer. Your line is open..

Hey, good morning, guys and congrats on the progress this quarter. I was wondering if you could first give us a little bit more color on the modification to the testing methodology that's being used to qualify patients for enrollment into the open-label study of SER-109..

Sure, Mark. Good morning. And maybe I'll ask Lisa to comment on the assay..

Sure. So as – recall that this is an open-label study with no placebo arm. And as such we wanted to facilitate as much access as we could for this population in this clinical trial. So physicians are now going to be able to use their local testing for study entry.

A toxin based testing approach will still be used to evaluate any potential recurrence while on study. But to enter the study they can use whatever methodology is used at their institution or in their area..

Okay. Got it.

Also wondering if you can offer any guidance on the timing of data from the SER-301 Phase Ib? And if you see any possibility of needing to modify SER-301's composition based on the insights you get from the microbiome biomarker data of ECO-RESET?.

Yes, Mark, let me – maybe I'll answer the first part of the question, I'll ask Matt to comment on the second. We haven't provided guidance except to say that we're making big progress on 301 and we're thrilled to have what we think is a franchise within the UC and the IBD space, right? We've got 287. We've got 301.

There are different shots on goal different opportunities. 301 is being studied in a 1B study in Australia and New Zealand. We made great progress. I think it's a technological achievement that we've been able to construct this cultivated or a synthetic approach based on the learnings from the 1B study from SER-287.

But at the same time we're incredibly excited about the signal we saw in the 1B space from 287. And we're thrilled about the opportunity to see these 287 – or IIB study results in mid-year.

Maybe I can ask Matt just to comment on the learnings from one to the other and how we think about that in general going forward?.

Sure. Good morning, Mark. So as a reminder, SER-301 is a consortium bacteria that was designed to reduce induction of pro-inflammatory activity, improve epithelial barrier integrity and TNF-alpha driven inflammation and epithelial cells then also to modulate various different UC relevant anti-inflammatory innate and adaptive immune pathways.

And as we talked about previously, the results from the 287 Phase Ib were certainly part of the design and use there for example understanding which specific bacteria are associated with clinical remission, which bacteria engrafted in different patient population.

But importantly, the design of SER-301 also includes that type of knowledge from across our clinical portfolio and our broad preclinical work where we've been working to identify specific bacteria that modulate various different innate and adaptive immune pathways.

And so, the way I'd like to think about 301 is designed to optimize the drug species engraftment and the pharmacological properties that are clinical and preclinical research have identified a potentially important microbiome drivers of a treatment effect.

And so, while there are similarities between the drugs there are also differences in terms of the targets that are optimized. We will of course continue to learn from our portfolio.

I think this is one of the values and differentiators for Seres is that we have both biologically sourced more complex consortia as well as these defined consortia both of which are in the clinic. We can continue to improve our insights around which parts of the microbiome are most important and continue to design those into our drugs.

So we have a high degree of confidence in both the 287 and 301 assays. .

Got it. And one final one for me.

I'm just wondering if we can expect any clarity on European regulatory requirements for SER-109 later this year that's something we might get some news flow on in 2021?.

Yes, Mark, we're continuing to work with our partners at Nestlé. Obviously, they were thrilled with the -- the Phase 3 study results. And we're engaging with Nestlé who owns ex-North American rights to SER-109 and we continue to engage with non-FDA regulators and those discussions continue. .

Okay. Thanks for taking the question and congrats again..

Thanks, Mark..

Your next question comes from Joe Thome from Cowen and Company. Your line is open. .

Hi, there and thank you for taking my questions. First one on the open-label SER-109 study.

Is there any way to estimate maybe how -- what proportion of patients would have only one recurrence in this study? And do you think the proportion of patients that do have long recurrence -- maybe FDA's labeling discussions? And then maybe one on SER-287 just when we're thinking about remission rates here.

Is there a level that you are shooting for? And then the enrollment patient population is a little bit different than the Phase Ib. So how should we be thinking about kind of the data in the context of what we've already seen from the program? Thanks..

Yes Joe, thanks for the questions. And I think -- I'm going to ask Lisa to comment on both of these. The first one was just as a reminder in the open-label study we had asked the FDA to allow us to include first recurrent subjects. To which they agreed. And we were pleased with that response.

Of course it opens up the pool of patients available to us in terms of enrollment for the open-label study, but we also think and Lisa made the comment in her prepared remarks that of course the label will be determined as part of a negotiation with the FDA as part of the BLA process it's an encouraging data point as we think about the field and how they may be looking at this.

Lisa do you want to comment on Joe's question regarding the proportion of first recurrence versus multiple recurrence in the open-label study and how we think about the label? And then maybe I'll ask Lisa to comment further on expectations around 287 with our mid-year readout. .

Sure. We can't really estimate right now. I mean the trial is ongoing and I mean we're really enrolling at a pretty good clip. So I mean the profile could change at any particular moment.

I would say that medically we view the first recurrence as our KOLs the first recurrent, second recurrent all have the same pathophysiology based in the fact that they've had an initial bout of C. diff. They've shown that their microbiome is not resilient enough to keep C. diff under control and they start in on this recurrent cycle.

So how many first recurrence versus others is going to be subject to a lot of factors. And I really couldn't give you a specific number. And then did you want me to take the next question as well, or did you... .

Sure.

Why don't you comment on -- on 287 as we think about expectations?.

Yes. So recall that we're in mild-to-moderate ulcerative colitis and this is the biggest group of patients out there in the UC space. Right now they can be on 5-ASA, which is where many of them are and there's a big toxicity gap if you will in terms of having to jump up into a much more significant set of toxicities for the next therapeutic steps.

So there's a lot of white space between 5-ASA and the next thing. So we're looking to find a -- to have a therapy that provides a meaningful benefit, a clear safety profile and is oral. And with that I think these patients who are smoldering along on their 5-ASA and unable or unwilling to move to the next step we'll have another option..

Thank you very much..

Thanks for your question Joe..

Your next question comes from Ted Tenthoff from Piper Sandler. Your line is open..

Good morning everyone and thank you so much for the update exciting progress. My questions kind of have to do with sort of some of the commentary you were making on the manufacturing side. So, with respect to the clinical supply for 109, 287, and then also 301 with the fermentation.

Is all of that currently done in-house, or is it outsourced? And if outsourced when will it be brought in?.

Yes, Ted, thanks for the question. Maybe it's worth a little bit of perspective or background and then I'll ask Dave to comment since he's with us this morning. And I think Dave is illustrative of some of the pivot that we're making as a company from clinical to commercial.

But when the company was founded, there was I think an appreciation that in order to really control your destiny in a new modality that manufacturing and owning key aspects of manufacturing would be critical.

I think there's, in general, an under appreciation of the importance of what we do from the CMC perspective and a quality perspective and the fact that those capabilities both on the biologically source side of the house as well as the synthetic or the cultivated side of the house.

They're just simply not commoditized, right? So, there's key steps in both sides of the house that we control that we own that we think are again not commoditized. We do work with outside parties for certain aspects of the supply chain and the manufacturing process.

But certainly we think that there's key capabilities that we've built up over the last decade that position us to move forward in both sides of our platform with quality and with speed. And maybe I can ask Dave just to comment a little bit further on that..

Sure Eric. Thanks and nice to be with you. Nice to meet you Ted. So, indeed I've been with Seres a little more than six months now. I've been really impressed with the work that they have done to invest in both sides of the technology that we're talking about here both those donor-derived programs as well as the cultivated fermented programs.

And so we do have the capability to support the pipeline of clinical supply for both sides of that house. And I think it's also really important to emphasize that the Seres has capabilities in anaerobic bacteria both with spore and non-spore forming formulations.

And so we really see that differentiating us in terms of our internal capabilities and with strategic partners that we do have to ensure that we're successful..

That’s really helpful and I appreciate the approach. Thank you very much..

Thanks for the question Ted..

Your next question comes from Chris Howerton from Jefferies. Your line is open..

Thanks so much for taking the questions and obviously, very exciting times for the company. All right. So, maybe for me just a couple of kind of reminder housekeeping questions might be most helpful. First, with respect to the BLA submission for SER-109.

Once kind of the open-label safety database is completed, can you kind of just walk us through what the expected next steps in time are might be for that program? And then -- yes, go ahead Eric sorry. .

Yes, sorry Chris. I -- so we're continuing to do the work across functional areas to support the BLA. I think we've said before and I'll reiterate this morning the open label we feel is really the key critical path item in terms of moving forward. So, as we said this morning, we're very pleased with the progress. We're over two-thirds enrolled.

Obviously, we've got the follow-up as Lisa mentioned following the full enrollment that we expect in the third quarter. But we're continuing with the work around other aspects of the BLA and we expect to be in a good position following this open-label completion..

Got it, okay. All right, very good. And then maybe just a couple of other ones if I may. The -- I can't remember if we've discussed in the past just maybe are you expecting to have an advisory committee for this program would be another kind of just general housekeeping question.

And then the second, maybe category could be, as we're kind of approaching commercialization as well as some very meaningful readouts certainly for 287. Can you remind us of what any milestones might be achieved from your relationship with Nestlé and any other if you want to remind us kind of what the commercial relationship is there for 109, (2).

And then the third question, I guess, maybe is for Matt which is I think it's interesting that we'll get the top line remission type data for 287 initially and then the biomarker data later. So just would love to hear your perspective on what that additional information would add to the story at that time? Thanks..

Sure. So let me -- I might lose the next three questions, but I think we start with a question around the advisory committee. Maybe at least I can comment I think our expectation is that we -- it's certainly possible that we would have an advisory committee.

Maybe Lisa if you want to comment then I can take it back with the milestone question?.

Yes. I think just as you said we would -- Eric said, it's a new modality totally new modality. So our expectation would be yes..

Yes, okay. We have not guided future milestones with Nestlé, Chris, except to just remind folks that they've been a terrific partner for us. It was a great deal that we within -- in 2016. Their support has been critical for the company in the last couple of years.

But we have not guided as to what future milestones would be from them for a clinical or a commercial progress.

I will remind you that Nestlé owns ex North American rights to SER-109 commercial, right? So, certainly, as we have kind of driven the bus from a clinical or regulatory perspective in the US than those responsibilities and our ownership lies with them ex North America.

And then the last question around 287, I think it's a great one and maybe I'll ask Matt to take that one. Just in terms of what we're expecting from a -- or what we may learn from a -- from the microenvironment analysis from 287. I think Matt might have commented on this a little bit earlier, but Matt why don't you take that one. .

Sure. Thanks. Good morning. Chris. So, yes, perfect. Thanks for the question. Look, as Lisa said earlier, I think, first and foremost, we got to remember this mild-to-moderate patient population is a major unmet need where there's a real gap and also one of the least studied populations in UC.

So the SER-287 trial Phase 2 trial was designed as all our trials are to be translationally rich and including a fair number of time points both in induction and maintenance where we can evaluate the types of things we typically evaluate, which are the bacterial species that are engrafting, how is that driving broader changes in restructuring of the microbiome in terms of other bacteria that may either be pro-inflammatory or other bacteria we know play important roles in host immunology.

And then, importantly, digging into both the functional changes that happened, as a result of those changes in the microbiome, and then also how changes in gene expression in the colon and epithelial barrier change in response to those changes.

And I think where we are as a company as you know we've been investing heavily into our research engine at the company for 10-plus years now where we have a broad strain library of bacteria that are functionally characterized, that are genetically characterized various different proprietary data sets where we can generate high-resolution information on species and even strains of species.

All of which allow us to really dig into the key underlying mechanisms of the drug and identify which bacteria are specifically associated with clinical remission or endoscopic improvement and as well as what metabolizes matter.

And then I think the real power of our platform is we've invested just as significantly in all of these preclinical assays in human -- customized human cell-based assay for doing microbiome studies and in vivo models where we can take our learnings about those bacterial signatures and biomarkers in the clinic and actually test causality in a laboratory setting.

And it's the basis of that kind of work that has been at the heart of all of our rationally designed consortia as well..

Well, I certainly do appreciate that Matt. And I think the great work that you've done to kind of develop all this in the field is certainly appreciated by me. So thanks for answering the question as well..

Thanks Chris..

Thanks for the question, Chris..

Your next question comes from Terence Flynn from Goldman Sachs. Your line is open..

Great. Thanks for taking the questions. I was just wondering if you could give us an update on where you stand with 109 commercial prep? And any latest perspective from payer conversations you might have had lately? Thank you so much..

Yeah. Terence. Thanks for the question. We continue to do work as we outlined in the prepared comments, but maybe I can ask Terri to comment a little bit more specifically on your question..

Sure. Thank you, Terence and Eric. Really, we've been quite busy even since our last earnings call getting ready for commercialization.

And so I think Eric has mentioned some of this in his prepared remarks, but in particular scaling our market education efforts, right? We have an enormous effort around medical communications planning, which has included of late deploying an MSL force into the field.

We're also obviously doing an enormous amount of published -- publication planning as well as Congress involvement and abstract presentations at upcoming congresses. So more and more of the data from the very successful ECOSPOR-III trial we'll be reporting out led by Lisa von Moltke's team and medical affairs.

We're also developing moving kind of to the payer. I'll kind of dip in and out and then I'll go deeper into that at the end of my remarks. We're developing and deploying a robust payer value proposition. Obviously, with the help of those very important customers, we have a lot to talk about with SER-109.

And so really narrowing the focus to what is most important to that very important customer audience is really the work that we're doing. We have a great story to tell. The feedback has been very positive. We're also continuing to enhance our understanding of the commercial opportunity segmenting physicians.

We have work underway to do that and really prioritize the physician audience in terms of who we're going to reach when, as we prepare for launch. We continue to do pricing and reimbursement analysis sort of in parallel with that value proposition work. And we're building infrastructure. I mentioned the deployment of the MSL team.

We're also hiring I've hired a couple of commercial leadership roles of late and we're beginning to build out the team. Because all of the clicking on the payer a little bit. I think you may have noticed in our slide deck on our website. We have a slide that kind of summarizes the feedback that we're getting from payers and physicians.

But what I would say is that the payer reception has been quite positive. They recognize the value that SER-109 is bringing. And they actually -- if you look at the value rating they give, it's very similar to the not so recently launched life-saving HCV medications like us of all the inharmonious.

So we're quite pleased with the response to the profile. And our task now is to -- as we move forward to launch, we have plenty of -- we have time to do this, but determine the right pricing corridor and working with these external customers. And I'll turn it back to the next question. .

Your next question comes from Gobind Singh from JMP. Your line is open..

Hi. Congratulations on the progress you're doing with SER-109, and thanks for taking my questions. I guess for me just curious coronavirus world where we're seeing for example lower rates of flu and probably increases in other diseases.

Are you guys seeing any differences in terms of CDI in populations compared to what it was before? And would be curious, if you can share any comments about how patients are doing on efficacy wise with first-time CDI versus what was studied in the open label? And -- or if not, maybe you'd be willing to help us how we should be thinking about that.

And then related to the prior program that you guys had in development, I believe this was one or 262 maybe for primary CDI if -- assuming there's a label that allows you broad applicability, how should we be thinking about 262 coming forward if at all then? Thanks..

Yeah. Gobind, there's a few questions there. Maybe I'll try to hit them. In terms of the coronavirus, it is a good question in terms of are we seeing fewer cases? All I can tell you is that there's only so many data points that we have.

One of the data points, it's just the enrollment in the open-label study, right? And from that perspective, I think we feel strongly that particularly with the profile that is available with SER-109, we have a lot of confidence and this continues to be a major issue.

And sometimes, when you have the type of profile or step function advancement in the potential of helping patients that we're showing with 109, the opportunity becomes even more acute. So in terms of those data points, I think, we're -- we certainly continue to be comfortable and confident that there's a major unmet medical need that we can help.

In terms of efficacy and the open label, we don't have that -- certainly have not commented on the data. On 262, let me just comment that I think that there's a major franchise here that we're thinking about. Obviously, with the data on 109, we're thinking about how we can help patients across certainly not just infectious disease or C.

diff, but certainly the -- our opportunity set in other indications more broadly. But within 109, within the recurrent C diff population -- with the C. diff population, we are thinking about other ways in which we can help patients and we're actively involved in discussions on that.

I will say our efforts have been really titrated and focused on getting 109 (2) patients first. But certainly, we're thinking about other opportunities to all patients within that franchise..

Thank you..

Thanks for the question..

Your next question comes from Vernon Bernardino from H.C. Wainwright. Your line is open..

Hi everyone and congrats on continued progress with all the clinical programs, definitely looking forward to the total 109 reveal and approval. The only question I had left was, could you remind us what Nestlé's role is in 109 commercialization.

What they currently are doing to prepare for the launch? And will you provide any details on the results of your market research? Terri provided some details I think -- or things that you might talk about. But just wondering what kind of details you reveal from your market research? Thanks..

Yes Vernon, just to remind you and the group. Nestlé has ex-North American commercial rights to SER-109. So Seres owns US rights -- or actually North American rights to SER-109 commercial. So that's the structure of that relationship.

I do think we put out a fair amount of detail including in our corporate deck related to some of the findings from Terri's work. And Terri, I think has provided that some additional color and commentary around that. And then I think it's likely that we'll continue to do that as we move forward.

But bottom line is that, the reception that we're getting from the field has been -- continues to be very positive and gives us a lot of confidence in the commercial opportunity in this agent going forward.

Not easy to find comps, not as easy to find analogue, simply just because there really hasn't been the combination of efficacy and safety that we saw in the ECOSPOR Phase II results. So, we do think that SER-109 is going to stand by on its own and we're thrilled with the opportunity to all patients with it..

Okay.

And can you comment on what Nestlé is doing ex-North America?.

Well, as I mentioned before, we're processing the Phase III results. We're in discussions with them around next steps and we continue to be in discussions with the ex-North American regulating bodies as well in terms of how we move forward with 109..

Okay. Thank you..

Great. Thanks, Vernon..

There is no further question at this time. You may continue..

So, thanks to everyone. We appreciate your time this morning. We look forward to continuing to update you on our progress, including at our UC Investor Event on June 21. Be healthy and well and have a great week. We look forward to speaking with you soon. Thanks very much. .

Ladies and gentlemen, this concludes today's conference call. Thank you for participating. You may now disconnect..