Seres Therapeutics, Inc.

Ladies and gentlemen, thank you for standing by. My name is Desiree and I will be your conference operator today. At this time, I would like to welcome everyone to the Series Therapeutics First Quarter 2025 Earnings Conference Call. 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. If you would like to ask a question during this time, simply press star followed by the number one on your telephone keypad. If you would like to withdraw your question, again, press the star one. I would now like to turn the conference over to Dr. Carlo Tanvi of Investor Relations. You may begin.

Thank you and good morning. Our press release with the company's first quarter 2025 financial results and business updates became available at 7 a.m. Eastern time this morning and can be found on the investors and news section of the company's website. The company has also posted an updated corporate presentation to the website. I'd like to remind you that we'll be making forward-looking statements, including statements about the timing and results of our clinical studies and data readouts, future product candidates, clinical development plans and commercial opportunities, communications with, feedback from, or submissions to the FDA, upcoming presentations, future payments related to the valve sale, operating plans and our future cash runway, our ability to secure partnerships and or generate or obtain additional capital or financing, are planned strategic focus, anticipated timing of any of the foregoing or 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 Schaaf, Series President and CEO, and Mirella Thorell, Chief Financial Officer. Additional members of the management team, including Dr. Matthew Henn, Chief Scientific Officer, Dr. Terry Young, Chief Commercial and Strategy Officer, and Dr. Dennis Walling, Senior Vice President of Clinical Development, will be available during the Q&A portion of the call. And with that, I'll pass the call to Eric.

Thank you, Carlo, and good morning, everyone. Today, I'll share business highlights from the first quarter and provide an update on our progress advancing 0155. During our recent full-year 2024 results call, we provided an in-depth review of our programs and recent data, and therefore, we will keep our remarks more abbreviated today and focus on progress updates. Advancing 0155 into the next stage of development in alloHSCT remains our top corporate priority, and we are making significant progress towards initiating the next clinical study. As a reminder, our Phase 1b study showed that 0155 administration resulted in a 77% relative risk reduction in bloodstream infections compared to placebo. This represents a highly meaningful outcome in this high-risk alloHSCT patient population. We also observed a favorable safety profile in this study, consistent with the favorable safety profile we've seen historically across our live biotherapeutic product platform. The clinical results generated to date underscore the potential of 0155 to redefine the standard of care for alloHSCT recipients, and the many other vulnerable patient groups at risk of bloodstream infections. We believe that developing 0155 and other live biotherapeutics to prevent infections in alloHSCT and other adjacent patient groups, including autologous HSCT patients, cancer patients with neutropenia, CAR-T recipients, individuals with chronic liver disease, and solid organ transplant recipients, could represent significant improvement for patients and multiple substantial commercial opportunities for CERES. Last month, members of our team attended the recent European Society for Blood and Marrow Transplantation Conference, and we obtained encouraging commentary from the transplant community that provides support for our mission and echoes what we've heard from U.S.-based physicians. Healthcare providers emphasized that preventing bloodstream infections remains a major clinical challenge and new approaches are desperately needed. Many physicians also expressed enthusiasm for both the safety and efficacy results observed in our SEER 155 Phase 1B study. Importantly, many also communicated their interest in participating in further SEER 155 development efforts. Our planned phase two study is expected to include multiple sites in Europe, so it is certainly encouraging to hear the support from European physicians. Additionally, our poster received the best clinical poster award from the EBMT Scientific Organizing Committee, providing external validation of both the patient need for CR155 and the rigor of our science. We also reported compelling exploratory translational biomarker data that reinforced the intended mechanisms of action of 0155. The data support that 0155 strengthens gut epithelial barrier integrity and induces immune homeostasis, findings that align with the observed clinical efficacy. These results further demonstrate the broader potential for live biotherapeutics to address inflammatory and immune diseases. Guided by constructive FDA feedback, including recently received, wherein the FDA recommended that we conduct a standalone phase two study as our next step, we plan to submit a 0155 phase two study protocol to FDA in the coming weeks. Our aim is to achieve a time and capital efficient path to clinical data. We are pleased with the productive interactions we've had with the FDA, which have been facilitated by CR155 having breakthrough therapy designation. And we are incorporating FDA's feedback into the design of the Phase II study protocol. As a result of our interactions with the FDA, we believe that we have the information needed for a rigorous Phase II protocol design. The study is expected to be well-powered, placebo-controlled, and target enrollment of 248 participants undergoing alloHSCT with a primary endpoint of preventing of bloodstream infections. We anticipate incorporating an adaptive design and an interim data analysis when approximately half of the enrolled participants have reached the primary endpoint. Based on our preliminary operational plans and anticipated enrollment rates, we believe we could obtain interim results within 12 months of study initiation thereby rapidly informing next steps in allo-HSCT development in pursuit of additional clinical development opportunities targeting adjacent patient populations such as auto-HSCT. If successful, we think the efficacy and safety parameters of the Phase II study could be used to support the design of what we anticipate being a single registrational study for approval of SIR 155 in allo-HSCT. As we prepare for the phase two study, we are moving forward with operational activities to support study initiation and execution, including having selected a CRO, commencement of study startup activities, and manufacturing clinical trial material. In parallel with these internal efforts, we are actively engaging in partnership discussions. As previously discussed, we would seek to collaborate with an entity that can provide financial support and that would help CERES realize the full clinical and commercial value of CR155. As you know, the biotech financing environment remains challenging, and we believe that obtaining the support of an external party who can provide financial and other resources is our best option to move CR155 forward and achieve the next clinical data milestones. Regarding our broader strategic goals, we believe 0155 and other live biotherapeutics have significant potential not only in the HSCT patient population, but also in additional patient groups at risk of bloodstream infections, including other blood cancer patients, CAR-T recipients, solid organ transplant recipients, individuals with chronic liver disease, and individuals in the ICU and long-term care facilities. I also want to highlight the potential that we see for live biotherapeutics to address various gut-related inflammatory and immune diseases, such as IBD, including ulcerative colitis and Crohn's disease. In each of these diseases, the gut epithelial barrier is known to be compromised, and this has been identified as a core component of underlying pathology. During the first quarter, we presented exploratory biomarker data from our Phase I study showing that SIR-155 was associated with improved epithelial barrier integrity and lower concentrations of various plasma biomarkers associated with systemic inflammation, such as interferon gamma, TNF-alpha, IL-17, and IL-8 in the HSCT peritransplant period, which is the period from the end of the first SIR-155 treatment course through to neutrophil engraftment. Additionally, at the recent Digestive Disease Week Conference, we presented data that could help identify and stratify patient subgroups most appropriate for a live biotherapeutic intervention and that could facilitate clinical development efforts in IBD and other immune-related diseases. We were very pleased to have received a Poster of Distinction Award in the Microbiome and Microbial Therapies subgroup at DDW. We continue to assess options, including through potential partnerships, to further evaluate these exciting I&I opportunities. With that, I'll now turn the call over to Mirela to review the financial results.