Good day, and thank you for standing by. Welcome to the Protara Therapeutics conference call. At this time, all participants are on a listen-only mode. After the speaker's presentation, there'll be a question-and-answer session. To ask a question during the session, you need to press star one one on your telephone. You will then hear an automated message advising your hand is raised. To withdraw your question, please press star one one again. Please be advised today's conference is being recorded. I would now like to hand the conference over to your speaker today, Justine O'Malley, Senior Vice President of Investor Relations. Please go ahead.
Thank you, Kevin. Good morning, and thank you all for joining us today to review the updated results from our ongoing open-label phase II ADVANCED-2 clinical trial, TARA-002, in patients with non-muscle-invasive bladder cancer, or NMIBC. The press release and scientific poster outlining the updated data can be found on the investor section of the Protara Therapeutics website. Before we begin, I would like to remind you that during today's call, we will be making certain forward-looking statements. These statements represent our view as of today only and should not be relied upon as representing our views as of any subsequent date. Actual results may differ from our forward-looking statements due to various factors, including those described in the risk factors section of our most recent annual report and subsequently filed quarterly reports that are on file with the SEC.
Except as required by law, we disclaim any obligation to update these statements, even if our views change. Joining me on today's call are Jesse Shefferman, Co-founder, Director, and Chief Executive Officer, Dr. Jackie Zummo, Co-founder and Chief Scientific Operations Officer, and Pat Fabbio, Chief Financial Officer. With that, I will now turn the call over to Jesse.
Thank you, Justine, and thank you all for joining us this morning. We are excited to share with you positive interim results from our ongoing phase II ADVANCED-2 clinical trial in patients with non-muscle-invasive bladder cancer, or NMIBC. With this data now in hand and several additional milestones anticipated throughout the year ahead, we believe that we are well-positioned for success and represent a compelling opportunity for the investment community. At Protara, we are 100% focused on the patients we hope to serve, and nowhere is this more applicable than with our lead investigational therapy, TARA-002, which will be the focus of our discussion today. TARA-002 is a cell-based immunopotentiator in development for the treatment of NMIBC. With the promising clinical results we will share today, along with TARA-002's demonstrated favorable safety profile and ease of administration, we believe TARA-002 belongs in the discussion about next-generation NMIBC treatments.
Beyond NMIBC, our rare disease programs represent de-risk opportunities that could drive significant additional value for the company. We encourage investors to familiarize themselves with these programs, which we have described in our public filings, and we expect to be able to share clinical trial results from these mid to late-stage programs in 2025. However, as stated, today our focus will be on our NMIBC clinical program. Before Jackie takes us through the data, I will spend a few minutes reviewing why we believe TARA-002 is uniquely positioned to become a meaningful addition to the evolving and expanding NMIBC landscape.
The slides we are sharing today are consistent with our expectations that TARA-002's unique mechanism and significant reinduction salvage rate would drive strong six-month responses, which we believe underscore the role of TARA-002 as an important potential new treatment for BCG unresponsive patients, where we are enrolling a registrational design study. Additionally, we're encouraged by the responses seen in BCG naive patients, which further support TARA-002's potential in other settings. These response rates, including 100% durability of complete response from three to six months and a reinduction salvage rate of 80%, are very encouraging. Additionally, TARA-002 has differentiated features that offer potential benefits to patients and physicians. It has a demonstrated favorable safety profile, a simple 15-minute administration via catheter, and no special handling requirements. We believe TARA-002's activity and unique product characteristics have the potential to drive significant utilization and adoption upon approval.
I will now turn it over to my colleague, Jackie, to walk you through TARA-002 and these interim results.
Thank you, Jesse. TARA-002 is an investigational genetically distinct strain of Streptococcus pyogenes that is inactivated while retaining immune-stimulating properties. TARA-002 is manufactured under GMP conditions in the same master cell bank as the originator therapy, OK-432, which was developed by Chugai Pharmaceutical and is approved for lymphatic malformations and a number of oncology indications in Japan. OK-432's label includes indications in lung, gastric, head, neck, and thyroid cancer, and has over 65,000 patients in its safety database. The FDA has confirmed that TARA-002 is comparable to OK-432, and Protara has worldwide rights, excluding Japan and Taiwan. Other investigational treatments for NMIBC are either enhanced chemotherapeutics or targeted immunotherapies. TARA-002 activates all of the same cytokines that other approved or experimental therapies do, but 002 has a much broader profile that we believe has the potential to drive a durable anti-tumor response.
Mechanistically, TARA-002 and BCG are similar, as they are both bacterial immune potentiators that drive a Th1 pro-inflammatory response and have a preference to M1 polarization. Where the two drugs differ is that 002 is a NOD2 TLR2 agonist, and BCG is a TLR4 agonist. When we compared TARA-002 to BCG, we found that 002 resulted in significantly stronger tumor cell killing compared to BCG, with higher upregulation of key pro-inflammatory cytokines and chemokines, including TNF alpha and interferon gamma. We believe these important mechanistic differences between TARA-002 and BCG support the meaningful efficacy seen to date with TARA-002 in BCG unresponsive patients from our phase I and our phase II programs, and this gives us confidence that TARA-002 has the potential to be an important therapeutic option for patients who no longer respond to BCG.
Now I will walk through the interim results that are being presented today in a poster at the Society of Urologic Oncology meeting. We are presenting interim data from our ongoing phase II open-label ADVANCED-2 clinical trial assessing intravesical TARA-002 in NMIBC patients with carcinoma in situ, or CIS, plus/minus papillary disease. These patients are either BCG unresponsive or BCG naive. The BCG unresponsive cohort has been designed to be registrational in line with the FDA's updated 2024 BCG unresponsive NMIBC guidance. Patients in the trial receive an induction course with or without a reinduction course of six weekly intravesical instillations of TARA-002, followed by a maintenance course of three weekly instillations every three months. The dataset includes 20 patients who are evaluable at three months, 18 patients who are evaluable at six months, and three patients who are evaluable at nine months.
There are five patients in the BCG unresponsive cohort and 15 patients in the BCG naive cohort. The data cutoff was November 19, 2024. Across all patients, TARA-002 demonstrated a 72% six-month landmark complete response rate and a 70% complete response rate at any time. In the pivotal cohort of BCG unresponsive patients, the CR rate was 100% at six months and 80% at any time. In the proof-of-concept cohort of BCG naive patients, the complete response rate was 64% at six months and 67% at any time. While we wouldn't expect our response rates in BCG unresponsive patients to remain at 100%, as we enroll more patients, we are encouraged by these initial data and believe they demonstrate the strong potential for TARA-002.
Our key priority is BCG unresponsive patient enrollment. By the end of this year, we will have more than 25 sites open in the United States. Our international expansion is also underway across Asia and South America, as well as other regions. We expect the promising results we are sharing today to generate excitement and interest in the trial. As for our plans in BCG naive patients, we believe the data we've generated in this setting are promising and in line with the efficacy seen with BCG. We believe TARA-002 could be an interesting alternative to BCG in earlier treatment settings. We are planning to engage the FDA in the first half of 2025 to confirm our development plans in BCG naive patients. And now I will let Jackie talk through our swimmers plot.
Thank you, Jesse. Moving on to the swimmers plot, we are pleased with the initial durability that we are seeing. TARA-002 demonstrated 100% durability from three months to six months in nine of nine patients. In addition, of particular interest, 002 demonstrated an 80% reinduction salvage rate across all patients. This compares to a roughly 50% high watermark in other immune-activating therapies that have employed reinduction for non-responders at three months. The similar reinduction and durability dynamics we observed in both BCG unresponsive and BCG naive patients leads us to believe that there will continue to be similarities in the effect of 002 across both patient populations. Finally, in this dataset, there were three patients who were evaluated at nine months, and two of those three patients maintained a complete response at this time point.
Moving on to the safety results, you will see that TARA-002 demonstrated a favorable safety and tolerability profile with no grade two or greater treatment-related adverse events to date, and no patients have discontinued due to adverse events to date. The majority of AEs were grade one and transient. The most common were in line with typical responses to bacterial immune potentiation, such as flu-like symptoms, and those associated with the urinary tract instrumentation effect. To summarize, we find these interim results exciting, and we look forward to accelerating patient enrollment in the BCG unresponsive cohort and expect complete enrollment of the proof-of-concept BCG naive cohort early next year. Now I'll pass it back to Jesse to close.
Thanks, Jackie. We are clearly pleased with these encouraging interim data. TARA-002's six-month complete response rate and safety and tolerability profile are promising. These data reinforce what we learned from our earlier dataset, specifically that our response rates increase over time, driven by 002's unique mechanism of action, consistent maintenance dosing, and a significant reinduction salvage rate. When patients progress to BCG unresponsive disease, they fall into a category for which there are currently few options, and they risk radical cystectomy. Most patients will choose any option available to avoid this radical surgery. Today's compelling data, combined with 002's ease of administration and reliable manufacturing, would make this a unique treatment and attractive choice for these patients and brings 002 to the forefront in the discussion of the evolving NMIBC treatment landscape.
Looking ahead, our near-term priority remains driving enrollment in our design-to-be registrational BCG unresponsive cohort in ADVANCED-2, and secondarily, determining the appropriate next steps to continue studying BCG naive patients. With our recent financing in April, we have runway to reach several exciting milestones in 2025. In NMIBC, we expect to present data in 12 months of evaluable patients from the ADVANCED-2 clinical trial in mid-2025, and with global expansion underway and new clinical sites coming online, we remain on track to have six-month results in 25 BCG unresponsive patients by the end of 2025. In our rare disease programs, we expect to share interim data from our registrational trial with IV choline chloride for patients on parenteral support and additional data from our phase II trial in children with lymphatic malformations.
It's an exciting time for Protara and we look forward to providing additional updates as we make progress in 2025 and beyond. I would now like to open the call up to Q&A.
Thank you. Ladies and gentlemen, if you have a question or a comment at this time, please press star one one on your telephone. If your question has been answered and you wish to move yourself from the queue, please press star one one again. We'll pause for a moment while we compile our Q&A roster. Our first question comes from Stacy Ku with TD Cowen. Your line is open.
Hi, good morning. Congratulations on the compelling data. Thanks very much for taking our questions. So we had a few. So first, big picture, where do you envision TARA-002 now slotting in the treatment paradigm following first-line BCG? And if you could comment on the size of the market ahead of cystectomy, even in a third or fourth-line setting, I think that'd be really helpful as we look at this data. So that's the first question. And then the second, as you look at other companies developing agents in BCG unresponsive population, how are you thinking about the patient split between CIS-only patients and concomitant CIS papillary patients? So curious how you're thinking about that and what split you see in other studies and what you might be considering for your own. So that's the second question.
Then the last, just helpful to walk through the swimmers plot, but when you talk about that salvage rate, just maybe help us to understand or characterize those BCG unresponsive patients, that single one that didn't achieve complete response after induction at three months. Thanks so much.
Thanks, Stacy. So I'll take the first one, and then I might pass this over to Jackie on the split of the CIS versus concomitant papillary. So look, big picture, our contention has always been that once you're through a threshold of efficacy in the unresponsive setting, and indeed in the naive setting, then you have to think about what your product characteristics are. And as we look at today's results and see that we are demonstrating sort of competitive response rates at six months, we also note that we have a significant safety and tolerability profile as well as ease of administration. So when you think about all the things that in this market kind of matter for adoption, our view is that we tick all the boxes: ease of administration and competitive efficacy along with a safety profile that is really favorable.
So I see us being in the discussion at the forefront of what's a doc going to reach for first when they have a patient who is BCG unresponsive. In terms of the size of the market, for BCG unresponsive patients, our view is that that market is not only substantial enough to kind of bear multiple entrants, but that it will probably grow. We're going from a situation where your current approved products offer somewhere between kind of 30% and 40% response rate at six months to places like 70% or numbers like 70% and 60%, as demonstrated with 002 and some of the other novel therapies kind of in development. That means that more people are avoiding cystectomy and staying in the prevalence population where recurrence rates until there's a cure are going to stay what they are.
Our view is you've got lots of different mechanisms. As Jackie mentioned, there's targeted immunotherapies, enhanced chemotherapeutics, and now you've got 002 as a broad-spectrum immunopotentiator. That's a third sort of type of mechanism in the mix here for the unresponsive patient population. The world has done a pretty good job of sort of quantifying what the kind of revenue opportunity is, and we think that it is substantial. Let's remember that NMIBC is the sixth most prevalent cancer in the United States and fourth most among men. There's a lot of room for multiple players. Again, we feel like these data, along with our profile, should have us right at the top of the discussion when docs reach for something for an unresponsive patient.
That's helpful, and then the concomitant CIS papillary patients, that split between CIS-only and kind of how other studies have been developing their drugs.
Sure. So maybe the first point to make is that concomitant papillary disease is a more difficult disease state to treat than CIS-only. We see that if you kind of take a look at our data in the data table, you can see that we did break out CIS-only versus CIS with papillary disease. And the drug does have a higher response rate in the CIS-only population, but it also has an encouraging and meaningful, and I think clinically meaningful response rate in the concomitant papillary patients as well. One of the most important things to do, I think, for any organization that's looking at this patient population and studying them, is making sure that the patients that come into the trial are appropriate for a clinical trial.
Some of the T1 patients, and we learned this early on from our own dataset, some T1 patients really aren't suited for it. You need to follow AUA guidelines. You need to ensure that restaging and regrading of those T1 patients are done. You need to ensure that if you're using historical or archival tissue for baseline, that you're ensuring, again, that T1 is really what the disease state of that patient is in and that they haven't progressed to T2 at the start of the trial. And we're taking all of these measures to ensure that we are putting proper patients into the study. I'm still encouraged by the fact that we have a 50% complete response rate in a larger or, sorry, a more difficult patient population to treat.
In addition to that, if you look where you can sort of ascertain from other sponsors their mix of CIS-only versus CIS plus concomitant papillary disease, we have a higher percentage of patients that have concomitant disease, and we're still at a very clinically meaningful, encouraging CR rate. So I'm very encouraged by that, and I think that 002 will continue to provide clinical benefit in both CIS as well as CIS with papillary patients.
Okay. Incredibly helpful. And then I guess that last question around that one BCG unresponsive patient that didn't achieve complete response after reinduction, could you just give more details around kind of the background of the patient?
Yeah. So, Stacy, I'm looking at it. I think you're referring to patient number seven, which is a BCG naive patient that had reinduction but did not actually achieve CR. On the swimmers plot, I don't see which patient you're referring to that was BCG unresponsive. All patients who were BCG unresponsive that received reinduction were complete responders at six months. I can tell you about patient seven if that's the patient you're referring to.
Oh, yes. Patient seven. Thank you.
Sure. Okay. No problem. So that patient, BCG naive patient, that patient was a CIS plus Ta at baseline. That patient is one of the patients that is someone we learned from, is what I would say, in that they should have been relooked at at baseline. We used archival tissue, and that patient did progress to T1. It's likely that that patient had T1 at baseline, and we didn't catch it.
Incredibly helpful. Thank you so much for the clarification.
One moment for our next question. Our next question comes from Leland Gershell with Oppenheimer. Your line is open.
Hey, good morning. We appreciate this positive update, and thanks for taking our questions. Just a few from us. Jesse or Jackie, I wanted to ask with respect to better efficacy in patients who are already unresponsive to BCG or exposed to BCG versus naive. I think we also had seen evidence of that in the earlier data cut back in April. Just wondering if you could just offer any perspective there and how that may relate to other programs in NMIBC to the extent to which they've broken out different populations with disease with respect to BCG. Thanks.
Sure. Thanks, Leland. Yeah. Look, I think so far, it's kind of early for us to make a definitive call. I would say we suspect that patients who show up that have previously been exposed to BCG carry with them a degree of trained immunity. That makes them tend to respond quite well to 002. We're still talking about a small end, but as we've sort of teased out what we could from the investigators that are really focused on sort of mechanism and the biology, our best working thesis right now is that BCG-exposed patients bring with them, as I said, trained immunity that helps accelerate their response. And at least that's what we're working with now.
As far as naive data, I believe we're the first to really look at it from the perspective of drugs that are under investigation to report on a BCG naive population, a meaningful enough number of patients to be able to draw conclusions from. I think the takeaway from the naive setting is that TARA-002 is performing pretty well. I mean, it's performing almost as well as BCG, pretty close, and could potentially be a BCG alternative.
Okay. Great. And our second question has to do with sort of this concept of CR at any time. This is sort of a metric that we've been seeing in other programs report as well. I wanted to hear maybe just maybe from interactions with urologists or maybe even regulators, what role does this CR at any time play versus CR reports at particular time points?
Yeah. Leland, that's a great point. So just as a reminder, our primary endpoint for approval that we agreed to with FDA is, as you said, CR at any time up to the six-month time point. I personally think that a more clinically meaningful and more relevant assessment for six months is just landmark. I mean, in CR at any time, you can have a CR at three months and then fail at six, or you, like some of our patients, could be not yet a CR at three months but then achieve CR through reinduction and be a complete responder at six months. Both of those patients would have a 100% complete response rate at any time, but I'm sure we can all agree you'd rather be the second of the two and disease-free at six months. So that's sort of our viewpoint.
We, of course, will always report CR at any time because that's the regulatory endpoint. But I think durability is increasingly the game here. And just if you or a family member had NMIBC, you would want to be disease-free for as long as possible. So from our perspective, we've talked a lot about 002's mechanism and how it could potentially be predictive of durable responses. As you've seen in this dataset, we've had an encouraging 100% kind of durability of response from three to six months. And even the nine-month patients, while a very small n, it seems that we're demonstrating a level of durability that's encouraging there too. So yeah, I think CR at any time is useful, but CR at time points is really how these investigational products and approved products are going to be evaluated by the treating community and patients.
Thank you. And finally, Jesse, you'd mentioned plans for looking at systemic priming, perhaps combination therapy. I think you've been doing some non-clinical work there to support those initiatives. Just want to check in and see how those plans may be coming with respect to clinical work as we get into 2025.
Yeah. So first of all, look, we're really excited and proud of the results that we are demonstrating in this dataset, albeit early. I think it shows that this can be a really powerful therapeutic option for NMIBC. But until the world has achieved 100% complete response at all times, it's sort of our job to keep pushing the envelope. And so look, of all the investigational products out there, only 002, because it's completely inactivated, can be administered systemically. Everything else has to be administered intravesically. And from our perspective, sort of interrogating the possibilities out there with systemic administration starts with the priming study where you'll administer one systemic dose at a time point sort of two-to-three weeks ahead of the initiation of intravesical instillation.
And the idea there is, as you can see, if you can reach a response quickly, which we believe priming will acquaint the adaptive immune system with this pathogen sort of a lot faster than through intravesical absorption. Look, if you can get to a complete response quicker, that gives that durability profile of 002 an opportunity to really take hold. And so we'll be looking at that. And then, of course, sky's the limit once you demonstrate that you are maintaining an immune response through systemic administration. We'll really want to, in the coming years, see what our options are there. And in terms of combination.
Really?
In terms of combination, just very quickly, I don't know of any oncology setting that, as it matures, doesn't move to sort of multimodal therapies. And so we anticipate that rather than just sort of being acceptable for where the market is today, we want to be looking ahead. And if this oncology market in NMIBC looks like any other oncology market, there's going to be combination therapies. And I would just state that I don't know of any other investigational or recently approved therapy that doesn't have overlapping toxicities with other agents. 002 has zero overlapping toxicities with any other agent that's out there, including BCG. So that's sort of a story for 2025. But again, this is until you're at 100% complete response rates that are really, really durable, patients and providers, and as should we, are going to be looking for 100% CRs.
Super. Thanks so much for the additional color.
Thanks, Leland.
One moment for our next question. Our next question comes from Michael Schmidt with Guggenheim Partners. Your line is open.
Good morning. This is Brittany on for Michael. Thank you for taking our questions. First, I wanted to speak a little bit more about the acceleration of enrollment that you alluded to. While this early efficacy data is certainly very promising, we're excited to see these results continue in larger numbers of patients. So what efforts are you implementing to increase the enrollment of this cohort, and what gives you the confidence in this acceleration of enrollment?
Sure. So thanks, Brittany. We have been in the process of expanding geographically for quite some time. The thing about running clinical trials outside the U.S. is that you have mandated regulatory timelines. And we undertook that process in early 2024 so that we could be positioned in 2025 after we kind of had a chance to take a look at efficacy and safety to be able to sort of put your foot on the gas, if you will, and go in the unresponsive setting. So what we did was we actually targeted countries around the world and geographies that have an abundance of BCG. The FDA has made it clear that they are not concerned about all patients being unresponsive to BCG type. There are other strains around the world that patients are unresponsive to as well.
What we did was we targeted our efforts in the countries where BCG is in abundance because we believe that's where the BCG unresponsive patient populations will be. We will obviously continue to expand in the U.S. as we have, as Jesse mentioned, but you've got a lot of patients out there in the world that could benefit from 002. We have now started to get our RA approvals, move into opening our first sites in South America. We're targeting Asia just based on the size of the population, as well as the fact that they do have BCG Tokyo in most of the countries over there. That's what our efforts have been.
I'm confident in our ability to be able to enroll the unresponsive population in those countries, mainly because we take a very hands-on approach to the way that we manage our clinical trials and the outreach that senior management at Protara does to ensure that our PIs are hearing from us and are understanding the role that they play and how important they are to us and to our trial, and I think that the relationships that a company forms with the PIs is what actually makes them successful in clinical trial enrollment.
Great. Thank you so much. And just to confirm, is the enrollment goal for the BCG unresponsive cohort still 75-100?
Yes.
Great. Thank you. And just one more question, if I may. What treatments have the BCG naive patients been exposed to? It looks from the background table like they've been exposed to TURBT and maybe an incomplete dosing of BCG. Have they been exposed to any other competitive drugs that might have some reserve to potential follow-on effect?
Yeah. So you're talking about the BCG naive specific population? So most of those patients have had some form of chemotherapeutic, whether it's gemcitabine, gemcitabine plus docetaxel, mitomycin. That's where we've seen the majority of the pretreatment in that population. And then we do have coming into our study now some patients that have recently failed newly approved products, but they're in the unresponsive setting where those products are approved.
Thank you so much.
Sure.
Again, ladies and gentlemen, if you have a question or a comment at this time, please press star one one on your telephone. One moment for our next question. Our next question comes from Matt Kaplan with Ladenburg Thalmann. Your line is open.
Hey, good morning, guys, and congrats on the encouraging results. Just a quick follow-up on the prior question in terms of the cadence of enrollment. I guess, where are you in terms of number of sites that you've initiated, and where do you expect to be, I guess, in the next few months in terms of opening up new sites to help to enhance the cadence of enrollment?
Sure, so our goal is to have at least 50 sites around the world. That's our goal. We expect to have all of those sites open by the end of 2025. Where we've been majority focused is in getting through the sort of long process of the academic centers in the U.S. because we know that those are really where we're going to find unresponsive patients. They treat the harder-to-treat patient population, and that's where we've seen in our previous studies where a bulk of unresponsive patients will come from, so we've been focused there as it relates to the U.S., as well as targeting community practices where a large number of patients are being treated, and they have sort of a factor to activation, if you will, just given the central IRB process and just the way that those community centers work.
We started our ex-U.S. regulatory submissions and strategies in literally January of 2024. Each country is different. Each country takes a different amount of time, but we are already approved in three ex-U.S. countries. We have active sites in two of those. We're about to open up our first site in our first South America country. We are filing in China, Japan, and Brazil. And those are, again, all large regions that have abundance of BCG based on the strains that are available there. So that's how we've approached this. And we expect those large Asia countries to come online in the, I would say, mid to second half of 2025 to really bring and round out our overall enrollment.
All right. Thank you for the added detail.
Sure.
And I'm not showing any further questions at this time. I'd like to turn the call back over to Jesse for any further remarks.
Thanks, Kevin. Thanks, everybody, for your Q&A, and before we leave, we would like to just make sure that we thank the patients, the physicians, the families that have participated in this clinical study, and the investors and other stakeholders that have come along the ride with us. Our objective is to stay doggedly focused on patients and making sure that we are a meaningful difference maker in the NMIBC setting, so thanks, everybody, for joining today, and we look forward to catching up as we release data in 2025 and beyond.
Thank you, ladies and gentlemen. This does conclude today's presentation. You may now disconnect and have a wonderful day.