Thank you for attending our healthcare conference. We are very pleased to have a BioAtla team here. We have Jay Short, CEO and Co-founder. We have Eric, Chief Medical Officer, and Sheri, Chief Commercial Officer. Thank you for coming, and welcome to our conference.
Thank you for inviting us, Dev. It's a pleasure to be here.
Great. So we can jump into fireside chat. So for those listeners who might not know the story, can you take a few minutes to provide an overview of the company and key features of the pipeline?
Yeah, I'll do my best here, Dev. I just want to say that BioAtla is both the inventor and leader in conditionally active biologics or CABs. This technology allows us to take targeted therapies and direct them to tumor cells while not attacking your normal cells. And this is very important since this allows us to not only improve the safety of these therapeutics but also the potency. It effectively increases the therapeutic window or therapeutic index. I'd also like to add, we have three key focus areas that are very exciting, the first of which is our CAB CTLA-4, which is showing a very encouraging efficacy and safety with both partial and complete responses. We just came out of ASCO, where we provided an update on our phase I clinical trial.
We believe that there's this differentiated, emerging profile for that efficacy and safety relative to approved agents and also other agents that are in clinical development. We are on track to establish, initiate a registrational trial by year end and have, have set up meetings, with the FDA to discuss, targeting, first and foremost melanoma and the BRAF, subset of patients mutant, which comprises about half of the melanoma patients. And so we believe this has got the opportunity for a more focused trial with a potential, full approval with just a progression-free survival. Very exciting type of opportunity. Number two, we also have a, what we believe is a very, good profile emerging on the CAB-ROR2 and head and neck cancer. We have 11 responses out of 29 of evaluable.
In addition, as of this moment, we now have six confirmed responses, up from five on the last report here just a couple of weeks ago. It's an ongoing trial, so we believe this is continuing to develop. We believe that the opportunities in the second line therapeutics are, second line of therapy is very good, given the low bar there, with the current therapies. We also believe the safety profile allows us to both consider monotherapy and combination therapy, either in second line as well as first line, and we are going to be meeting with the FDA to discuss both of those aspects.
I think the last point, which is really critical, is our current work on establishing a key partnership, 'cause we I think we recognize that while we have some efficient and potentially very rapid endpoints with some of our clinical trials that we're directed toward, we're going to need a collaboration to help fund some of that work, and we're... That has always been on target for the has been a goal for the second half of this year. We remain on track for that, and so we're quite optimistic in view of multiple high-value clinical assets as well as preclinical assets. So, we're very encouraged by that.
So those three key areas, I think CTLA-4 and ROR2, as well as strategic collaboration, are key areas of focus for us right now, Dev.
Great. And, you recently presented phase I data on evalstotug, which is BA3071, at ASCO. Can you briefly summarize the data and what and when the next data readout that investor can expect?
Thanks, Dev. So, we had a great ASCO, and it was exciting to present the evalstotug data, which just as a reminder, we've knocked out the binding of the CTLA-4 antibody in tissues with normal pH, so we can focus really on the tumor microenvironment. We observed several durable responses, and importantly, from a safety perspective, we observed one patient with grade 3 gastritis that resolved with steroid treatment and another patient with new-onset diabetes. So this is 2 out of 21 patients that had grade 3, and this compares quite favorably to marketed CTLA-4 products in terms of the safety profile. And the enrolled patients with advanced cancer generally remained on treatment for extended intervals. At the 5 mg per kg dosing, patients received an average of 7.2 doses, which is substantially higher and longer than marketed products, the tremelimumab and ipilimumab.
So taken together, we're enthusiastic about our responses, the durability of responses, and the safety profile that we're observing.
So another exciting thing is you are currently studying evalstotug at one gram level, which is 14.2 milligrams per kg, which is very high. If safety is clear, what is the possibility of keeping these dose escalation versus this being the last escalation cohort, and what is the path forward for the drug?
Yeah, so that's a great question. For those who are familiar with the CTLA-4 field, dose really matters, and so higher doses, higher exposures, are contributing to long-term improvement in survival, not just progression-free survival, but overall survival at multiple year follow-ups. So for that reason, many in the field of CTLA-4 are really trying to push the dose to the highest levels of exposure, and very importantly, in our PK/PD modeling, we're finding that, by using the 1-gram dosing, we're able to maintain, trough levels of CTLA-4 blockade to keep above the EC50 level for all patients.
I'm really pleased at this meeting to report that we have cleared the 1-gram level, and so that's a dose that we would like to discuss with the agency for next steps in our pivotal trial in melanoma and potentially other indications.
Right. So coming right after, out of ASCO, was there anything at ASCO from the competitive space that might have caught your eyes?
So at ASCO, it was a really productive meeting because of the head and neck data that were important, but I was really focused on the CTLA-4 experience. We saw the Relativity trials read out, and it's an illustration that it's so important to come up with safe regimens for melanoma patients. We saw that ipilimumab was added to the LAG-3 nivolumab to make it a triplet. People were excited with those data, and at the same point, there were some very significant toxicities associated with CTLA-4 that our drug seeks to ameliorate.
And, so we'd like to again pursue our drug in a BRAF population because we believe that it's the BRAF patients that have been demonstrated to really benefit from CTLA-4 blockade when combined with PD-1 therapy.
Right. Transitioning into your, next program, which is ROR2 ADC ozuriftamab vedotin. You recently disclosed phase II data in head and neck cancer. Can you please summarize the data for the audience?
Sure. So we're now shifting to our antibody-drug conjugate that targets ROR2. It's called ozuriftamab vedotin, and we disclosed that we have phase II data in head and neck cancer. We treated a total of 33 heavily pretreated patients. They had a median of 3 prior treatment regimens, ranging from 1 to 6 prior lines of treatment. Everyone had prior PD-1 experience, and almost all patients had previously been treated with platinum-containing regimens. So we observed responses among 11 of 29 evaluable patients, and as Jay just mentioned, we now have 6 confirmed responses to date. One of the responders achieved a complete remission and presently maintains that complete remission. Not surprisingly, the 6 confirmed responders had a median of only 2 prior lines of treatment, while the 5 unconfirmed responses were more heavily pretreated, having a median of 3.
Great. So, what is the bar for ozuriftamab in head and neck cancer from your perspective? And how are you thinking about opportunity for ozuriftamab in the context of pembrolizumab?
Yeah. So we believe the bar for a refractory head and neck population is a response rate of around 25% and a duration of response anywhere between 4-6 months, depending on second line, third line. So we believe that the opportunity for ozuriftamab vedotin in the second line and beyond setting for head and neck is quite strong. Given the manageable safety profile, the robust responses, and anti-tumor activity that we're seeing, we believe that given the high unmet need in second-line head and neck, as well as the low bar, it really represents a really good promising path for ozuriftamab vedotin in head and neck cancer.
Great. Coming on to the next program, which is your AXL ADC mecbotamab vedotin BA3011, which is progressing in UPS. Can you provide a status of this program and next step, and what are you viewing the opportunity for this asset in UPS?
Sure. So, moving on to this AXL antibody drug conjugate that is conditionally binding mecbotamab vedotin. All 20 of the UPS patients were dosed in April, and we added another one in early May for a total of 21 patients, and that's undifferentiated pleomorphic sarcoma. We're on track to have a meeting with the FDA in the second half of the year to discuss the second part of this potentially pivotal study. Our goals with the FDA meeting are to confirm our accelerated registrational path that's based on overall response rate with acceptable durability. Then we'll also be talking with the agency about Project Optimist requirements. Of course, as everyone knows, Project Optimist will be looking at dose and response and safety and making an integrated analysis to pick the best dose to move forward.
We believe that the current dose we're using, where we're giving the antibody-drug conjugate on days 1 and 8 regimen of every three weeks, has excellent safety, and we're looking forward to reporting the data for the efficacy of that regimen.
Great! And, maybe to the audience, what are the key drivers for the remainder of the year?
The opportunity in UPS? Yes. So, UPS represents one of the largest subtypes of sarcoma. Oh, and the key drivers for the remainder of the year. So there are really five-
Maybe we can talk about the opportunity first.
Yes, that's what I thought.
Yes.
Yes. That's what-
Sorry.
-where I was going. Sorry. Yeah, so it's one of the largest subtypes of soft tissue sarcoma and has a very high unmet need given the limited therapeutic options. So we believe mecbotamab vedotin can achieve a peak of $500 million worldwide in UPS alone, with a relatively small commercial infrastructure. Given responses that we've seen in other soft tissue sarcoma subtypes, we also believe that there's a really good opportunity for a confirmatory label expansion study across all soft tissue sarcomas. So quite a good opportunity in UPS alone, but also a good opportunity for label expansion across all soft tissue sarcoma.
Great. And, jumping onto the key drivers-
Yeah
... maybe you can remind to the audience.
Yeah. Thank you. So, we actually have five key drivers for the remainder of the year. The first is evalstotug monotherapy in refractory melanoma and carcinomas at the 350 milligram level, with some patients at the 700 milligram level, and that is planned for an R&D day in a few weeks in July. The second key driver, again with evalstotug, is in combination with pembro in a front-line melanoma setting, and we plan to report that data out in the second half of the year. The third is the FDA feedback that we're anticipating for evalstotug in front line BRAF-mutated melanoma, for ozuriftamab vedotin in head and neck cancer, and mecbotamab vedotin in UPS, to how do we finalize the second portion of the UPS study for registration.
So with that feedback, it enables initiation of at least one potentially registrational trial. The fourth, which Jay mentioned earlier, is an important corporate goal for us, is to establish a strategic collaboration for at least one of our phase II clinical assets. And then finally, it's the phase I data readout for our dual CAB EpCAM T-cell engager bispecific, which again, is slated for the second half of the year.
Great. Lot, lot of things to look forward for the rest of the year, and especially the R&D day that you mentioned. And, another important question is cash, cash position. Maybe if you can talk about the cash position of the company and what is the runway based on current spend.
Yeah. Given the fact that several of our ADC trials have really come to winding down and we're going into the FDA for discussions, our expenses are coming down both in second quarter as well as the rest of the quarters through the year here. And so our current cash balance allows us to get into the second half of 2025 without raising additional capital. Obviously, Sheri just mentioned, and I mentioned earlier, where one of our corporate goals is to establish a strategic partnership, which we believe will further assist us in positioning to initiate a pivotal clinical trial toward the end of the year.
And so we're, we think we have enough runway to accomplish what we need to do, and I think we're on track, and it's consistent with the goals that we set at the front of the year.
Great, and, we will wrap up our session here. Thank you for spending time with us, and looking forward to next milestone, including the R&D day, from BCAB.
Well, thank you-
Everyone for attending. Sorry.
Thank you, Dev, and I appreciate that. Thank you to all for the attendance and, we look forward. We're gonna be setting up our R&D day in around mid-July, a couple of weeks. We were originally targeting to the end of June, but we're gonna put that probably just to align with KOLs and other things for around mid-July. So we look forward to seeing everybody there.
Yeah, great. Thank you.