PLUS THERAPEUTICS, Inc.

Good afternoon, ladies and gentlemen, welcome to the Plus Therapeutics first quarter 2024 results conference call. 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, including the risks and uncertainties described under the risk factors section included in PLUS Therapeutics annual report on Form 10-K and quarter 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. Mark 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 first quarter 2024 financial results. 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 by reviewing our recent corporate and clinical progress in the first quarter, and then turn the call over to Andrew to review our financials. Dr. LaFrance then will be joining us for Q&A. Let me begin by highlighting some recent corporate updates before discussing our specific therapeutic and diagnostic programs. So first of all, on May 9th, 2024, we closed a private placement financing for an aggregate proceeds of up to $19.25 million, which consisted of an initial upfront funding of approximately $7.25 million and up to an additional approximately $12 million upon cash exercise of accompanying warrants at the election of the investors. The financing included participation from AIGH Capital Management LLC with additional participation from healthcare-focused institutional investors and insiders. Second, we received a notice of award for $3 million grant from the United States Department of Defense congressionally directed medical research programs. The award will be used to fund a Phase I-II trial for pediatric patients with high-grade glioma and ependymoma following IND approval from the FDA. As a reminder, this grant illustrates our ongoing strategy to use external grant funding to support the initial preclinical and clinical development of new technology or indications while minimizing the impact to the balance sheet and shareholder dilution. More specifically, our GBM program had just been acquired when we found out that we had a five-year grant funding from the NCI to fund that program through Phase 1-2. Second, our LN program received nearly $18 million of funding over three years from SEPRINT. And today, that strategy continues with this DOD award for pediatric brain cancer therapeutic development. We're going to continue to leverage our novel technology, subject matter, and grant management expertise to drive this strategy forward for the foreseeable future. To strengthen our team for forthcoming pivotal trials, we added neuro-oncologist Dr. Andrew Brenner and Dr. Barbara Blau to our management team. Dr. Brenner is an MD-PhD and has been instrumental in developing rhenium-obispo-meta and the related clinical strategy. And Dr. Blau is a PhD with extensive experience in clinical operations, CNS tumor biology, biomarker development, and neoplasms of the cerebral spinal fluid. Now, in terms of our clinical programs, I'll begin with updates on our RESPECT-LM Phase 1 Dose Escalation Basket Trial for a single administration of rhenium obispo-meta for leptomeningeal metastases. This trial is substantially funded by a three-year, nearly $18 million product development award from CPRED. During Q1, we announced the enrollment of the three required patients for dosing in cohort 5, at a single radiation dose of 66.1 millicuries. As of the most recent data update in March 2024, 12 of 18 patients' dose remained alive. Multiple compassionate use doses have now also been made available to clinicians for patient survivors that have exceeded the trial follow-up period and continue to do well. We expect to present updated enrollment and safety data at the SNO-ASCO meeting in August 2024 in Denver. Furthermore, investigator and KOL enthusiasm for the trial and the investigational therapy remains high and continues to grow. Recently, we added an additional five sites to the trial that will participate in patient recruitment for both the phase one and subsequent follow-on trials. Our goal is to complete enrollment in the phase one basket trial for a single dose this year, and then to present the full data set from all cohorts of the phase one trial as they exist at that time at the SNO annual meeting in November 2024 in Houston. In parallel, we are presently in dialogue with the FDA regarding a multi-dose expansion arm of the phase one trial. Ultimately, we believe multiple doses of rinium-obispo-meta will be the optimal therapeutic approach to suppress and potentially cure LM. We will provide an update once the plan is finalized and FDA approval is obtained. Additionally, as we move forward towards a recommended phase two dose of rinium-obispo-meta for LM, we intend to expand our communications with the FDA regarding a pivotal phase two, three trial design which is currently in development with our team and KOL advisors. The initial planned pivotal trial will be focused on LM and metastatic breast cancer, for which we have orphan designation from the FDA. Last week, we hosted an investor call focused on the acquisition of the synergistic LM diagnostic platform called See Inside. Rather than fully revisiting the details of that call today, I would like to provide the highlights and encourage you to investigate the recording, which can be found on our website, to learn more about this tremendous new opportunity for the company. So here are the key highlights. And I'll begin with the four key points outlining the rationale for the acquisition. First of all, Leptomeningeal cancer is a tough diagnosis to make, and the current state-of-the-art diagnostics, which include MRI and cytology, lack diagnostic sensitivity. Second, we developed experience with the C-inside assay in our RESPECT-LM trial and saw firsthand its value. Additionally, we had the opportunity to engage with multiple KOL physicians who have come to see C-inside assay as a game changer in their practice. Third, autopsy studies indicate LM is likely significantly underdiagnosed. As such, an enhanced diagnostic such as C-inside means more patients may be able to take advantage of our rhenium-obispo-meta therapy for LM. Finally, we recognize that there is a substantial standalone commercial opportunity to develop, commercialize, and then monetize the C-inside technology in the near term. So based on that rationale and our supporting analysis, we exclusively acquired all essential C-inside-related assets to provide C-inside testing commercially, and this includes three types of tests. First of all, the cancer cell enumeration, or CTC, circulating tumor cell testing, which we call CSF01. This quantifies adenocarcinoma and melanoma tumor cells in the CSF. Second, we obtained the fish or fluorescence in situ hybridization testing we call CSF02 that determines cancer-specific gene expression for therapeutic guidance. And third, we acquired the next generation sequencing of cell-free DNA called CSF03 that analyzes DNA to identify genetic mutations related to LM. In Q1 2024, Prior to the acquisition, we validated and clinically implemented the CSF-01 test into our Respect LM trial as an exploratory endpoint and is currently in use today. As part of the acquisition, we acquired the 4C clinical trial data, which evaluates the inside and its clinical utility in addressing therapeutic decision-making at LM. And last week, we disclosed that the trial met its primary endpoint, and a presentation of the full 4C trial data is planned for the August 8th to 10th SNOW-ASCO meeting in Denver. So now looking forward in terms of next steps, we will be expanding the availability of the test in our RESPECT trial to longer time points in conjunction with our planned multiple dosing regime. We are also finalizing a complete business evaluation, including a reimbursement optimization strategy with the intention of commercially launching the test as soon as Q4 2024. As discussed in last week's call, we anticipate a total addressable market of over a half million tests annually with the potential for additional growth. We plan to further discuss the commercial opportunity and the plan at a later date. And finally, in parallel, we are talking to potential diagnostic business development partners that have expressed interest in C-INSIDE. And then finally, just a reminder, you can learn more about the C-INSIGHT asset or acquisition of that by visiting our website and looking at the related press release and investor call details. So now, shift gears, and regarding our RESPECT-GBM trial, evaluating rhenium obispumata in patients with recurrent glioblastoma. We continue to enroll both Phase II patients with GBM tumors less than or equal to 20 milliliters, and also Phase I patients with GBM tumors that are greater than that. And that's in our dose escalation Phase I that's still ongoing and now in Cohort 8. As the NIH NCI funding for this trial that I mentioned earlier, which has been the primary financial supporter for the trial, is winding down in 2024, And as we work to finish enrollment of the Phase 2 study, we are able to add new sites that will help speed trial completion and set us up for the Phase 3 study. So besides our Texas sites in Dallas, Houston, and San Antonio, we are now adding three new sites to the trial focused on key population centers. In the Upper Midwest, the Ohio State University. In the New York area, North Shore and Lenox Hill Hospitals, which are part of the Northwell Network. and in Florida, AdventHealth. These three to enroll in the second half of 2024 and will substantially contribute to a pivotal trial. We have set the goal for ourselves to complete enrollment in 2024 or early 2025, and enrollment timing will be influenced to a significant degree by participation of these new sites. We plan to provide a complete update on the Phase 2 data this fall at one of the key neurosurgery or neuro-oncology meetings, and that final meeting designation is to be determined. As a reminder, the data seen and reviewed to date in the Phase 2 trial has been highly promising in terms of both safety and efficacy, demonstrating thus far a 13-month overall survival as of November 2023 compared to approximately eight months for the standard of care, or 63% improvement in OS over standard of care. As I mentioned last quarter, given the safety profile and the unprecedented amount of radiation we can deliver to the CNS using our technology, we believe there's a tremendous potential for improving upon the standard of care in GBM, and also there's a broader opportunity to leapfrog the primary means of radiation delivery for all CNS neoplasms, which is essentially external beam radiation therapy at this point. We continue to work behind the scenes with existing and potential partners that share our view of this opportunity and want to collaborate to explore the potential in a focused manner. In parallel to our plans to finalize the Phase I and Phase II trials, we are also planning our pivotal trial strategy and plan to meet with the FDA later this year to discuss the Phase II data and align on a pivotal trial design in GBM. Finally, I would like to briefly update you on our pediatric brain cancer program. As I also noted at the beginning of the call, with U.S. Department of Defense funding support, we will be finalizing our IND with the FDA and initiating a Phase I trial for children with pediatric high-grade glioma and ependymoma. We anticipate, based on several previous rounds of discussion with the FDA, that we can obtain IND approval in 2024 and perhaps be ready to begin enrollment early next year at our initial site, Lurie Children's Hospital in Chicago. Once the final trial details are agreed upon, we will provide an update on those. Now, with respect to our next generation radioembolic device called rhenium-188 or 186 nanoliposome biodegradable degradable alginate microsphere, or RNL-BAM. As previously mentioned, feedback from the FDA is that BAM will be regulated as a device, not a drug. With that decision in hand, we are now working on the device-related quality system, finalizing the device design requirements, and expanding the related IP portfolio. And I anticipate providing more updates when warranted in the near future. Finally, Although our current supply chain is both reliable and sufficient for our near-term needs, as we contemplate pivotal trials beginning in 2025, we are devoting significant energy to build out a supply chain that is ready for both pivotal trials and ultimately commercialization. Two key focus areas are as follows. First is to have a redundant and high-capacity GMP manufacturing capabilities. So to complement our two existing manufacturers of the final drug product, we are in the process of selecting a third partner that meets GMP standards. This addition, serving as an alternative and redundant source, will ensure that collectively we can fulfill our demand projections for rhenium-obispo-meta through 2028. Second focus area is for additional radiation services capability. So to support the commercial radioisotope supply, a key part of the overall manufacturing process, we will need to expand our network of providers. We are currently well into that process today, and I'll report more as we are able to update. Moreover, we're enhancing both exclusive and non-exclusive supply agreements for key starting or intermediate drug products. We are also refining inventory-based strategies, to guarantee reliable drug availability under any foreseeable demand scenario. And with that, I'll now turn the call over to our Chief Financial Officer, Andrew Simms, who will review the financials. Andrew?

Thank you, Mark. Good afternoon, everyone. Please refer to our press release issued earlier today for a summary of our financial results for the first quarter ended March 31, 2024. The cash balance was $3 million at March 31, 2024, compared to $8.6 million at December 31, 2023. The company recognized $1.7 million in grant revenue in the first quarter of 2024, compared to $0.5 million in the first quarter of 2023. This represents CPRIG's share of the cost incurred for our rhenium abysmometa development for the treatment of patients with LM. We expect 2024 grant revenue to be in the range of $6 million to $7 million, i.e., tracking total operating loss for the first quarter of 2024 was $3.3 million compared to $4.8 million in the same period of 2023. The decrease was primarily due to increased grant revenue. Net loss for the first quarter of 2024 was 75 cents per share compared to $2.07 per share for the same period the prior year. I would also like to provide a more detailed update on our runway and cash position based on the recently announced private placement and provide guidance on our grant funding for the remainder of 2024. There are two additional sources of cash that PLUS has access to. beyond the balance disclosed in cash on hand and liquid investments on our Q1 2024 balance sheet. The first, as we announced last week on May 6, we closed a private placement fund financing of up to $18 million from new healthcare-focused institutional investors and company insiders. In addition, it should be noted that, as reported after market on Form 8K on May 9, This financing was subsequently upsized to $19.25 million, with a total of $7.25 million received at closing. This $7.25 million amount represents approximately 12 months of incremental runway at our current burn. The second source of cash remains our continued funding through now three announced grants. Firstly, the CPRIG grant to support the Respect LM trial. With respect to expected grant advances from CPRED in 2024, and to be clear, cash advances from CPRED, we are on track to receive advances totaling 6.9 million in 2024. 3.4 million will be received in late Q2 or early Q3, and an additional 3.5 million will be received in late Q4. An additional 3.5 million is then due from CPRED in 2025. Secondly, as reported on April 22nd, PLUS has received an award recommendation from the United States Department of Defense for $3 million to support the upcoming RESPECT pediatric brain cancer trial. This funding is expected to commence in late Q3 or early Q4 of 2024 and materially cover the costs of the planned phase one trial. Funding is generally received annually in advance and covers a three-year period. i.e. approximately $1 million will be received under this grant in 2024. PLOS also continues to benefit from the NIH grant to support the respect GBM Phase 1-2 trial. Although expected to be complete in 2024, it currently covers approximately 90% of the overall trial costs. We also continue to source other non-dilutive sources of grant capital. with the target of applying for at least $10 million per year. We will continue to only report on individual grants when they are awarded. Taken in total, this cash on hand placement financing warrants to fully exercise and committed and contractual grant revenue is in excess of $35 million. I'll now turn it back to you, Mark.