Good afternoon, ladies and gentlemen. Welcome to the Plus Therapeutics Fourth Quarter and Full Year 2023 Results Conference Call. [Operator Instructions] Please be advised that today's conference is being recorded. Before we begin, we want to advise you that over the course of the call and question-and-answer session, forward-looking statements will be made regarding events, trends, business prospects and financial performance, which may affect Plus Therapeutics' future operating results and financial position. All such statements are subject to risks and uncertainties and including the risks and uncertainties described under the Risk Factors section included in Plus Therapeutics' annual report on Form 10-K and quarterly reports on Form 10-Q filed with the Securities and Exchange Commission from time to time. Plus Therapeutics advises you to review these risk factors in considering such statements. Plus Therapeutics assumes no responsibility to update or revise any forward-looking statements to reflect events, trends or circumstances after the date they are made. It is now my pleasure to turn the floor over to Dr. Marc Hedrick, Plus Therapeutics' President and Chief Executive Officer. Sir, you may begin.

Thank you, Victor. Good afternoon, everyone, and thank you once again for taking the time to join us today as we provide an overview of recent business highlights and discuss our 2023 full year financial results. And right upfront, apologies for the hoarseness in my voice as I come back from the flu. Joining me for the call today are Mr. Andrew Sims, our Chief Financial Officer; and Dr. Norman LaFrance, our Chief Medical Officer. I'll begin the call this afternoon by reviewing our recent clinical and regulatory progress with a focus on the fourth quarter, and then turn the call over to Andrew to review our financials and Dr. LaFrance then will be joining us for Q&A. Let me begin with the updates on our two lead CNS cancer programs. I think we're in an enviable position in the development of rhenium obisbemeda drug, in that with the recent progress we have made in LM. This effectively means we have two promising lead clinical programs for LM and recurrent GBM. Our ReSPECT-LM Phase 1/2 dose escalation trial of a single administration of rhenium obisbemeda for LM continues to show positive safety and efficacy signals and is making very good progress. In November 2023 at the Society for Neurooncology Meeting, or SNO, we presented results from the [technical difficulty], we showed that 13 patients with LM received a single intraventricular dose of rhenium obisbemeda between 6.6 escalating up to 44 millicuries through an indwelling Ommaya reservoir. No DLTs were observed and the maximum feasible dose was not reached. The majority of adverse events were mild, 64% Grade 1 or moderate 27% Grade 2. And overall critical organ radiation doses were low. Rhenium obisbemeda circulated throughout the CSF space by one hour following administration and persisted in the CSF for up…

Thank you, Marc, and good afternoon, everyone. Please refer to our press release issued earlier today for a summary of our financial results for the fourth quarter and year ended December 31, 2023. As of December 31, 2023, cash and cash equivalents were $8.6 million compared to $18.1 million as of December 31, 2022. We are projected to receive an additional $6.9 million in grant funding from CPRIT in 2024, with $3.3 million in the first half of 2024, and a balance of $3.6 million by the end of the year. In addition, as Marc mentioned, the company continues to benefit from grant awards of $3 million from the NIH to support the GBM trial through Phase 2. Based on the cash on hand and committed grant funding, our current balance sheet provides runway into the second half of 2025. The company recognized $4.9 million of grant revenue during the year ended December 31, 2023, compared to $0.2 million in 2022, reflecting the progress made on the LM indication in 2023. We expect grant revenue will continue to increase during 2024 and the remaining term of the CPRIT grant through August 2025 as we plan to expand the LM clinical trial to add clinical sites and enroll additional patients. Total operating expenses for the year ended December 31, 2023 of $18.2 million compared to $19.7 million in the same period 2022. The decrease due to lower professional and legal expenses. Other income increased from $147,000 in 2022 to $400,000 in 2023 and fully offset interest expense. As a result of these changes, the net loss decreased by $6.9 million from $20.3 million in the year ended December 31, 2022, to $13.3 million in the year ended December 31, 2023. And now I'll turn it back to you, Marc.

Great. Thank you, Andrew. Before we move on to Q&A, I'll take a moment to provide guidance on selected key milestones anticipated over the next 12 months. First, we had safety and efficacy data from the Phase 1 ReSPECT-LM trial with the SNO/ASCO CNS meeting in August of 2024 and likely further update at the full-on SNO meeting in October 2024. We anticipate completing the Phase 1 trial in LM by the end of 2024, and we're on track [technical difficulty] conjunction develop a Phase 2/3 pivotal trial design for breast cancer patients with LM in conjunction with the FDA. We will also be working with the FDA in 2024 to develop a multiple dosing approach to potentially further extend tumor impact of the rhenium obisbemeda and leptomeningeal patients. In our GBM program, we intend to expand trial sites, as mentioned, and complete enrollment in the Phase 2 trial by late 2024 or early 2025 and in parallel finalized pivotal trial design planning with the FDA that's partially done at this point. Pending IND clearance from the FDA, we intend to initiate the Phase 1 pediatric brain cancer trial for pediatric brain cancer patients. And we also plan to bolster our rhenium obisbemeda supply chain for commercial readiness in 2024 as well as complete device development optimization milestones for our next-generation radioembolic device, RNL BAM. Now with those key milestones, I'll turn the call back over to Victor to introduce any questions we might have. Victor?

Thank you. [Operator Instructions] One moment for our first question. Our first question will come from the line of Justin Walsh from Jones Trading. Your line is open.

Hi. Thanks for taking the questions. You alluded to this, but I was wondering if you could provide some more color on the current availability of rhenium-186 and what it will take to scale up and meet potential clinical and then commercial demand?

Hi, Justin. It's Marc. So, if you kind of model out, I think, in the near-term, near-to-intermediate term, 2024, 2025, 2026, being in pivotal trials and having a commercial-quality, Phase 3 quality drug, we can essentially scale from our current providers. So, we're talking about maybe somewhere between five to eight doses a week, throughout the year that can be further scaled up, by adding more days to the week. So, what we're really doing is, kind of looking at commercial assumptions based on GBM, which is a much smaller indication. As you know, it's about 15,000 patients in the U.S. every year versus LM, which is a much bigger number of patients. So, that's going to require, as mentioned, an additional GMP manufacturer. So, we'll have at least two GMP manufacturers that can meet the GMP manufacturing goals that, we've set for ourselves from a commercial perspective. That should, you know, we're talking about now having five to 10 years of GMP supply from a manufacturing perspective. We also, we are also looking at increasing the radiation services provider, provided to a second provider as well, to make sure that radioisotope is, radioisotopic services is not a limiting in the overall supply chain. It's not limiting now. We have plenty of upside and ability, to increase specific activity with our current provider. But kind of looking downstream, three to five years, we'd have to bring on additional radiation services. And then, in terms of the other supply intermediates, we really have those pretty well in place. It's really about building up backup supply agreements, and then risk mitigation through increasing shelf life and improving inventory.

Got it. Thanks. One more question from me. You'd mentioned that you're still evaluating the long-term commercial potential of the CN side assay. I was just wondering if you'd share any initial thoughts about potential clinical utility of the assay outside of or, in addition to rhenium obisbemeda?

Yes. Thanks, Justin. So, from, I'll look at it, a few different levels. So, first, just from our trial, we see a step function improvement in diagnosis and also in disease management potential just in our patients, our small number of trials in our LM trial thus far. So, we see it firsthand, the value there. A kind of a second level, when we talk to clinical trial sites, which are the NCCN sites primarily in the U.S. And we talk to those principal investigators that are interested in our trial, they - this assay was off the market for a few months. There was really a big hole in there, from their perspective in their therapeutic and diagnostic armamentarium, not having that test. So, we, from their side to, from physicians and centers that weren't even in our trial. And then as we look at the magnitude of the under-diagnosis of LM. We think LM is probably two to four times underdiagnosed based on autopsy studies. When you sort of lump all those things together, it impacts us therapeutically, by significantly increasing the size of the market. And I know, Justin, you know this, but that's a very significant potential increase in our ability, to treat patients and create value for shareholders. And then there's also the opportunity to follow patients. So, if you're following patients over months or years, you're improving survival, this assay could be used as a potential surrogate biomarker, to determine when it's appropriate to retreat patients. And that sort of further magnifies the commercial opportunity. So, even though it's a diagnostic opportunity, it impacts us by expanding the therapeutic market. But also as a standalone diagnostic opportunity. It's actually very meaningful. We're not interested really long-term in being in the diagnostic business per se, but it's so closely aligned, with what we do therapeutically. And it's a very unique opportunity in an unmet medical area that, we think it's well worth going for it, from a commercial perspective. And that's our goal.

Great. Thanks for taking the questions.

Thanks, Justin.

Thank you. One moment for our next question. Our next question comes from Sean Lee from H.C. Wainwright. Your line is open.

Good afternoon, guys, and thanks for taking my questions. I just have two quick ones. First, for the CNS side assay, you mentioned that it's starting to be used, starting in the first quarter. So, will we start seeing more results based on that from, I guess, cohort 4 of the LM study?

Hi, Sean. Yes, I think, yes, I want to be clear. So, yes, the test is actually up and running. We have all 18 monoclonals up and running. We have the microfluidics, the transporters up and running. We missed, more or less, we missed cohort 4 when the test was unavailable. We're in cohort 5. And so, you'll start seeing additional data from cohort 5 on. That's our goal. So, absolutely, we're looking forward to having that data again, as are the investigators, quite frankly.

Great. Thanks for the clarification. And as a follow-up on that, for the potential future pivotal study that's coming next year, do you see CNS side serving as a primary endpoint for that study? Or will it be more used alongside more standard measures, such as the OS and response rate?

Yes, good question. I'm going to let Dr. LaFrance take the brunt of that question. But I - think most likely this will be used as an exploratory endpoint in our LM pivotal, Phase 2/3 pivotal trial. We just don't have enough data yet, to know how we might incorporate that as a primary endpoint. But I think long-term, it could be in LM. Another reason why we think it's a valuable test for these patients. But Dr. LaFrance, would you like to talk a little bit about primary endpoint selection in LM?

Sure, Marc. Thanks. And Sean, great question. And for LM, I think it's important to look at what our options are. So mentioning on the CN side, given the study and where FDA typically feels about surrogate endpoints, probably the most realistic, as Mark mentioned, is a secondary, or exploratory endpoint. And we'll be positioning that and getting some of those data as we progress the current Phase 1 monotherapy. And as Marc mentioned in his remarks, there are several additional LM programs that, will be starting later this year, or early next year. We would expect all of those to have the CN side assay in some regard, as a secondary or exploratory endpoint. Those data will really drive what makes sense in terms of generating the best pivotal database. But I think it's important to underline how the investigators feel about this test. And they've been using it, before the current - the prior company's difficulties in a lot of standard of care applications, and very successfully. In terms of trial endpoints, although we have reported OS, and of course, we know the agency likes an OS primary endpoint, I think we all need to remember LM is a very tragic, and difficult to treat complication, of a primary tumor. We would anticipate focusing on breast cancer with the leptomeningeal complications for several reasons. First of all, that's one of the main contributors to a leptomeningeal complication. And as we all know, FDA is very specific on wanting disease specific indications. And we've already accomplished their preliminary agreement by having orphan drug designation for that indication. In terms of endpoint, OS would certainly be one of the endpoints. I would anticipate that likely to be a secondary endpoint, despite some of our very provocative and promising preliminary information only, because we know that what drives these patients survival, is their primary tumor. In our current database, we have seen that the patients that although have gotten some benefit, both some clinical benefit. And certainly the benefits of CSF tumor reduction that Marc mentioned in his remarks, the patients that unfortunately have expired have all expired from the primary tumor. So the important thing with this indication will be the control of the leptomeningeal complications. So their medical oncologist can focus on the treatment of the primary tumor, giving them more runway for that. All of this needs to be reviewed with FDA and that's the plan. I'll stop here and see if that satisfied your question and happy to give you more feedback, if you'd like.

Thank you, Norman. That's very helpful. And my last question is for Andrew. Could you provide us with an overview of how much of the CPRIT grants are still left? And what's the - how much do you expect to recognize over the next year?

Hi Sean, thanks for the question. So at this point, we have additional funding expected from CPRIT of just over $10 million through kind of as I look at it from now, through August 2025, which would be the end of the three-year period. So how that - how we expect and how we forecast that to breakdown is really into three additional payments to be received. The first payment is - should be received kind of late in the first half of this year, and it will be about $3.3 million approximately. We then expect the next incremental advance in CPRIT to be $3.6 million, to be received on, or about the end of this year. And then the final piece and the balance will be received in probably early to mid-2025. If that answer your question.

Great. Thank you for that. That's all the questions I have.

Yes. Thanks, Sean.

Thank you. One moment for our next question. Our next question comes from the line of Edward Woo from Ascendiant Capital. Your line is open.

Yes. Congratulations on all the progress. You mentioned that you guys were going to look for $10 million of grant proposals this year on top of $7 million last year. What are you seeing in terms of the landscape for grant opportunities out there? Is the pot getting bigger, the pot getting smaller, pot about the same? And what about the competitive landscape of competing with other people looking for grants? How is that impacting your ability to get these grants?

Hi Ed, thank you. I don't see a big change over the last few years. Grants are hard to get. And the yield is low, which means you need to put a lot of them out there to get one or two. So, we are in an advantage not only, because we have unmet medical needs, but also we're a Texas-based company. And that opens up, what is still the second largest funder of cancer research in the world, which is the state of Texas and CPRIT. And we've had success. In fact, we have one of the biggest CPRIT grants ever given, which is for LM. So, I think we have a pretty good - we have a great - working relationship with CPRIT. We have a very good understanding of how to get those grants. We know that there are companies that have up to three of those grants, and we know the process for that. So I think, we'll continue to look not only at the more traditional U.S. governmental grants, but also look at CPRIT as well and in development. That non-dilutive funding allows us to really, to manage our balance sheet in a materially different way than we would otherwise have to. And so it really makes a lot of sense leveraging very experienced team in terms of getting grants, to continue to seek those for the foreseeable couple of years, or so as we hopefully bridge to improved product and revenue.

Great. Well, congratulations again, and I wish you guys good luck. Thank you.

Thank you.

Thank you. And now I'll turn it over to Andrew for any questions.

Thanks, Victor. So we have one question, and it's for Dr. LaFrance. What is the status of the pediatric trial? And when do you expect to start treating patients?

Thanks, Andrew. Great question. As everyone heard, Marc touched on that briefly at the end of his remarks that we had been to FDA, and we'll be following up with them for submitting the final IND for approval. I would add that FDA has embraced and are very pleased that with Plus and are pursuing the pediatric indications for high-grade glioma and ependymoma. So we have - we already have basically an agreement with FDA for the pediatric protocol. They had some final minor questions, not so much on the pediatric protocol conduct, which like I said, we have their preliminary agreement, but some additional - some GBM data that we've generated in adults around asymmetry, all of which is very straightforward. We committed to get that information back to them as we've enrolled more Phase 2 adult patients. We will be getting that data to FDA in the first half of this year, which we hope means, we will beginning and be able to enroll by second half of 2024, our first patients. Importantly, we have our pediatric site - first pediatric site identified, and preparation at that site is well underway and the principal investigators that, that site are already well engaged and partnering with us for that. So peds is on track, and it's been very well embraced by the agency.

All right. Andrew, any other e-mail questions?

That is it tonight, Marc.

Okay. Thank you. All right. I want to thank everybody for joining us. Again, thank you to the investigators and patients and their employees who work so hard, and we're obviously very excited about where the company is right now. And this is a great road ahead of us in 2024. So, we appreciate your time and your interest, and we'll look forward to talking to you next time. Thank you, Victor.

Thank you. Thank you for your participation in today's conference. This does conclude the program. You may now disconnect. Everyone, have a great day.