Conference Transcript - TARA 2026-09-15

Ashley Vanderbeck, Analyst — H.C. Wainwright

Hello, everyone, and welcome. My name is Ashley Vanderbeck, and I am a biotech equity researcher here at H.C. Wainwright, and it is my greatest pleasure to introduce our next speaker, Pat Fabio, who is the Chief Financial Officer of Protara Therapeutics. And with that, I will pass it off to Pat.

Patrick Fabbio, CFO

Thank you very much, Ashley. Happy to be here to walk you through our exciting programs at Protara. Please note, I'll make some remarks today that include forward-looking statements that involve some risks and uncertainties. Okay. Protara is a biotech company located in New York City, just about a mile down the road, with about 70 employees. We have three clinical programs in oncology and rare disease, all of which are in pivotal trials. We have several key clinical and regulatory catalysts over the next 6 to 12 months. Our oncology program is in NMIBC, where we are evaluating Terra002 in several trials. We are close to completing enrollment in our pivotal Advanced II trial in BCG-unresponsive patients. We have shared positive interim data from this trial in BCG-unresponsive and BCG-naive patients, both of which I'll review shortly. We also have the Exploratory Advance III trial, which is being redesigned to help us understand how Tara002 performs across broader patient populations, including BCG-naive, BCG-exposed CIS, as well as high-risk papillary patients across BCG exposures. The redesign of this trial is expected to accelerate and expand the breadth of data available at or around the time of the potential launch of Tara002 in BCGM-responsive. Tara002 has a differentiated product profile in NMIBC, which we believe has the potential to drive significant adoption among urologists, particularly those community practices, which is where the vast majority of patients are currently treated. On the right side, we have two rare disease programs, again, both with pivotal studies ongoing. We are evaluating Tara002, the same compound, in lymphatic malformations, or LMs, in the pivotal STARBORN1 trial, and this is in about 30 pediatric patients. Tara002 has received FDA rare pediatric disease. It's received orphan drug, breakthrough therapy, fast-track designation, and is PRV eligible. We intend to complete the enrollment in STARBORN1 by the end of this year and should submit a bla in the second half of next year our third program on the bottom right is iv choline chloride for patients on parental support or ps 78 of patients dependent on ps are choline deficient and the majority have some resulting liver damage Yet there is no approved IV formulation of choline. IV choline has been granted FDA orphan drug and fast-track designation and is already included in key medical guidelines for patients on PS. We are currently enrolling patients in a pivotal trial. Excited by our near-term milestones. As I mentioned, with the three programs, they're all in pivotal trials, and we have some exciting milestones ahead. We expect a complete enrollment in our NMIBC and LMS trials and share interim results from our IV choline trial all by the end of this year. Let me take a moment to talk about our lead compound, Tara002. Tara002 is similar to BCG. This is the standard of care in NMIBC. Tara-002 is a bacterial immune potentiator that ignites both the innate and adaptive immunity. It is derived from inactivated strep pyogenes and drives an anti-tumor Th1 immunological response. While similar to BCG, it also has several important differences in its safety and efficacy profile that make it a potentially exciting new option for patients. Okay, let me spend a little time on the BCG, on responsive data. So here you see the swimmer's plot. In the ADVANCE-2 trial, at the time of the data cutoff, which was January of 2026, the complete response rate at any time was 66%. It was 68% at six months and 33% at 12 months. This initial durability is encouraging, especially in light of the small sample size and the inherent challenges intrinsic to early landmark analysis with evolving data sets. In addition, you see that responders in the swimmer's pot are maintaining their CRs, demonstrating good potential for a continued durable response. You see that 100% of evaluable responders maintain their CR from 9 months to 12 months. So we are very enthusiastic about these initial results and expect to complete enrollment in this registrational study by the end of the year. So now let me move over to the BCG Naive cohort of 29 patients, which is fully enrolled. At the time of the data cutoff here was April of 26. The complete response rate at any time was 72 percent, 67 percent at six months, and 55 percent at 12 months. You know, we're pleased to see the 12-month CR rate continue to increase as longer follow-up accrues. Tara002 shows good sign of durability here in naive patients, with 91% of evaluable responders maintaining their CR from 9 months to 12 months. So we're pleased with these strong results in these naive patients. On safety, Tara002 has a favorable safety profile with the majority of treatment-related AEs being grade one and transient. We're glad that the team continues to hear very positive feedback from physicians about their experience with Tara 002. By now, I think there is a good general understanding that the NMIBC market opportunity is substantial. It's driven by annual incidents in the U.S. of over 25,000 and high-risk non-muscle invasive bladder cancer patients with an annual recurrence that it's multiples of that. Like all other companies in this space, our initial focus has been on BCG unresponsive. With the redesign of our ADVANCE-3 trial, we expect to take a more efficient path to expand the study of TaraO2 across a broader patient population, including BCG-naive, BCG-exposed, as well as high-risk papillary patients across all BCG exposures. This redesigned study reflects what we feel is an opportunity to accelerate and expand the breadth of data available at or around the time of potential launch of Tara002 in BCGM-responsive patients. So this reflects our confidence in our ADVANCE-2 trial. One other point, which we believe could be a game-changer in NMIBC, is that Tara002 is the only therapy approved or in development with the ability to be safely dosed systemically. And we continue to explore this opportunity. As we know, intravesical administration is burdensome for patients, and being able to use a sub-Q dosing for maintenance therapy could be a real benefit to patients. So here you see the results of a Bloomberg survey from about 50 urologists, we know that about 80 percent of NMIBC patients are treated in community urology offices. And in community practice, workflow and practice economics are really important. And here you see the data from the survey. And this highlights our view that in addition to predictable safety and tolerability, key elements such as product handling, administration, preparation time, and reimbursement are and will be critical when physicians make treatment decisions. When we look across the treatment landscape, it is clear to us that Tara002 is the easiest to administer with the least burden on both physicians, their practices, and their patients. Tara002 has a clean safety profile and is administered through a simple office-based intravesical installation with no viral handling, no special preparation, and no burdensome post-administration protocols for patients. This makes it easy to integrate into existing practice workflows. Compelling safety and efficacy combined with its off-the-shelf availability and fast, simple administration, we believe provide key competitive advantages for Tara002. Tara002 has a unique profile in the NMIBC treatment landscape. It sits at the intersection of what patients and urologists prioritize, safety, efficacy, and simplicity. Tara002 delivers robust single-agent activity with competitive complete response rate and encouraging durability. We truly believe these product attributes position Terra002 as a best in class next generation investigational therapy with the potential to meaningfully impact care in non-muscle invasive vladic cancer. So let me spend a few minutes talking about our LMs program. LMs are a rare congenital malformation of lymphatic vessels that results in failure of these structures to connect or drain into the venous system. There are three types of LMs. Macrocystic, which are large balloon-like cysts with well-defined fluid-filled sacs. Microcystic LMs, which are small infiltrative lesions with tiny cystic spaces. And then the third is mixed. Mixed cystic LMs, which are a combination of both macro and micro components. We are evaluating Tara O2 in macrocystic and mixed LMs, not in microcystic. Once diagnosed, treatment is almost always warranted in macrocysts as they can cause significant morbidity affecting breathing, swallowing, feeding, and speaking. Tara002 is being evaluated in the STARBORN-1 trial, and this is in approximately 30 pediatric patients. The results of this trial, we believe, should serve as the basis for approval. There are approximately 1,500 patients diagnosed with LMs each year in the U.S., with the majority of these patients being macrocystic, and there are up to 80,000 patients currently living with LMs. We believe that about 20,000 of these patients have macrocystic and mixed cystic disease and are seeking treatment. This is an attractive total addressable patient population, which we believe represents a sizable market opportunity. Currently, there are no FDA-approved therapies for LMs. Today, patients are treated with off-label sclerotherapy or surgery. The patient burden and high recurrence rates associated with surgery are well documented. The reported safety and efficacy of currently utilized sclerosins varies widely because of a lack of consensus dosing and administration guidelines, as well as a lack of well-controlled studies. This typically results in a significant variance in terms of patient outcomes and risks based upon provider preference and experience. There is a significant need for a more targeted FDA-approved option for LMs with macrocystic and macro-dominant LMs. But let me now walk you through the interim results that we shared from Starborn I early this year at the ISFA World Conference. As you see, this analysis includes 16 patients as of an April 10, 2026 data cutoff. 83% of participants had completed treatment. That completed treatment achieved clinical success. Of the patients who were assessed at the eight-week post-treatment time point, 100% of the evaluable patients achieved clinical success. In 80% of those patients, clinical success was achieved with just one or two doses of Tara002. It is clear to us that Tara002 demonstrates a clinically meaningful response in macro dominant disease. Okay, so this is a medical photography from three LM patients treated with Tara002. All of these patients, all three of these patients, achieved a complete response. As you can see from the photos, Tara002's effect is prominent across varying sizes of macro-dominant cysts. So let me spend a minute. The image on the left-hand side of the page is of the child who had a 1.7 liter cyst. You can see the size of that. And after four injections of Tara002, you can see the remarkable resolution. Moving on to safety, the majority of adverse events were mild to moderate with no serious adverse events reported. In summary, the positive interim data from STARBORN1 gives us confidence that Tara002 has the potential to be an important mainstay in the LM's treatment paradigm. As we prepare for the potential launch of Tara002, we anticipate a focused commercial launch that targets its efforts on the vascular anomalous centers concentrated as the vast majority of patients are treated at a small number of centers. We are confident that we can achieve commercial success with a relatively modest-sized commercial organization, and we are excited to begin the commercial infrastructure build as we eye a BLA filing in the second half of 2027.

Ashley Vanderbeck, Analyst — H.C. Wainwright

Okay.

Patrick Fabbio, CFO

Let me cover IV choline chloride, which is an investigational intravenous phospholipid substrate replacement therapy. This is for patients receiving parental support, or PS. Choline is critical for healthy liver function, as well as brain development, muscle function, and bone health. PS patients are unable to synthesize choline, and there are currently no available PS IV formulations containing choline. As a result, approximately 78% of patients dependent on PS are choline deficient. And out of those, 63% have some degree of liver dysfunction. This is a unique rare disease opportunity to be able to bring the first approved therapy to approximately 30,000 patients in the U.S. who are on long-term PS. We are in a registrational trial with a PK primary endpoint of increasing choline levels in the blood. IV choline has the potential to address a clear, guideline-supported, unmet medical need in PS. We're really excited about that opportunity. So I can wrap things up and, in summary, say, you know, as we advance across our late-stage pipeline, we believe we are well-positioned to deliver on a series of important clinical, regulatory, and operational milestones with the potential to create meaningful value for patients and patients and shareholders we remain confident that the potential of tara o2 to become a preferred treatment option for patients with bcg unresponsive nmibc we are also excited to continue evaluating tara o2 in a broader patient population of patients with high grade high risk nmibc through our redesigned advanced three trial, which is expected to accelerate and expand the breadth of data available at around the time of the potential launch of Tara-002 and BCG unresponsive. Our rare disease programs address significant unmet medical needs and represent significant commercial opportunities, further strengthening the potential of our pipeline. Thank you for your time and interest in our work.