PLUS THERAPEUTICS, Inc.

Good afternoon, ladies and gentlemen. Welcome to the Plus Therapeutics fourth quarter and full year 2020 results call. At this time, all participants have been placed in a listen-only mode, and the floor will be open for your questions following the presentation. If you would like to ask a question at that time, please press star 1 on your touchtone phone. If at any point your question has been answered, you may remove yourself from the queue by pressing the pound key. We ask that you please pick up your handset to allow optimal sound quality. If you should require operator assistance, please press star zero. Before we begin, we would like 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 Therapeutics' future operating results and financial position. All such statements are subject to risk and uncertainties, including the risk and uncertainties described under the risk factors section included in PLUS Therapeutics' annual reports 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. Mark Hedrick, Plus Therapeutics President and Chief Executive Officer. Sir, you may begin.

Thank you, Erica, and good afternoon, everyone. Thank you for taking the time to join us today as we provide a business update and discuss our 2020 fourth quarter and full year results. Joining me on the call today is Mr. Andrew Sims, our Chief Financial Officer. But before Andrew provides a brief overview of our financial performance, I would like to provide an update on our drug development activities, focusing my remarks on two key topics. First, progress on the clinical development of our lead drug, rhenium nanoliposomes, also called RNL, currently being developed for recurrent glioblastoma. And second, and update on additional potential clinical target indications for RNL, apart from the current glioblastoma. Now, for those of you who are new to the company, RNL, our lead drug, is a unique therapeutic consisting of isotopic rhenium-186, which is made in a fission reactor that is chelated with proprietary technology and loaded into 100 nanometer liposomes. RNL is interesting in part because it releases two energy types, beta energy for cancer killing and gamma energy for imaging. Our lead indication for R&L is recurrent glioblastoma, which affects approximately 12,000 patients annually in the U.S. and about the same number of patients in the EU. It is the most common and lethal form of brain cancer, and essentially all primary glioblastoma tumors will recur after initial treatment. The treatment of this devastating disease remains a significant challenge, and it's been about a decade since the FDA approved a new therapy to treat it. Not surprisingly, then, there is really no clear go-to standard of care for recurrent glioblastoma. And even in the few currently approved treatments, they provide only marginal survival benefit for those patients. So it's a real true medical need. Now, external beam radiation therapy is commonly used for glioblastoma, and its efficacy against GBM is about as good as it gets, or really better than any other potential treatment used today. Compared to external beam radiation therapy, whereby external energy or radiation passes through healthy tissue to reach the tumor, with RNL, it may be possible to deliver a radiation dose only to the tumor that is up to 15 to 20 times higher than with external beam radiation therapy as it's used today. And despite the super high doses of radiation delivered by RNL, and precisely because of its inherent tumor targeting capability, unwanted radiation exposure to nearby healthy tissue is actually reduced. Now the gamma energy produced by the RNL that I mentioned previously could actually be visualized in real time during the administration of the drug. This may allow doctors the ability to better control the radiation dose and distribution in order to more effectively treat both the bulk tumor and concomitantly the microscopic disease that's often left in the penumbra of healthy tissue. In 2020, R&L was granted both orphan and fast track designations from the FDA for treatment of patients with recurrent glioblastoma. And to further assist the company in its efforts to develop R&L successfully for brain cancer and other cancers, PLUS formed scientific and clinical advisory boards in 2020. These experts on our boards are leaders in the fields of neuro-oncology, neurosurgery, preclinical drug development, and nanotechnology, and will help guide and advise us as we advance our versatile proprietary nanotechnology forward. The ongoing RESPECT clinical trial is a Phase 1-2 design of up to 55 patients to determine the maximum feasible dose and to assess the safety, tolerability, distribution and potential efficacy of 186 RNL in recurrent or progressive malignant glioma funded to a significant degree. The trial is funded to a significant degree by the NIH or National Cancer Institutes. Through 2020 and into 2021 thus far, we remain on track and on plan for our RNL development program for glioblastoma, including winding up the phase one clinical program called RESPECT, optimization of the regulatory plan, and bringing the manufacturing and supply chains forward to industry standards in anticipation of the next steps in clinical development. In 2020, the Society for Neuro-Oncology annual meeting that was in November of last year, we provided an update on the RESPECT trial for RNL. At that time, interim data from the first 15 patients through cohort five and their SPECT trial were available. And that data can be found in detail on our website. But the interim data in brief showed that intratumoral RNL can successfully deliver up to 15 times the absorbed dose of radiation administered by standard external beam radiation therapy. RNL treatment volume and radiation dose were increased successfully from the earlier cohort's to the fifth cohort. Also, RNL was well tolerated with no dose-limiting toxicity observed, despite markedly higher absorbed doses of radiation compared to EBRT or external beam radiation. In our view, one reason we've seen no systemic serious adverse events or SAEs such as marrow ablation is that the radiation stays in the brain tumor and the adjacent tissue and exposure outside the brain is very low. And there's actually about a 3,000-fold difference between those two. Although the dose escalation part of the RESPECT trial is not designed to show efficacy per se, we have seen two long-term survivors greater than 30 months and a median and mean survival duration in subjects with tumor coverage greater than 75%, which is currently 8.9 months, and 13.6 months respectively and growing with six patients still alive. In the interim, we expanded enrollment to a third clinical trial site in the Anderson Cancer Center at Houston. We've completed enrollment of the three required patients in the sixth cohort of the RESPECT trial, increasing both the R and L drug volume and radiation dose once again. And additionally, I can tell you that we have treated one of an additional three planned patients at the cohort six dosage and volume, but with more aggressive drug delivery parameters. So thus far in summary, 19 patients with recurrent GBM have been treated in the respect trial. The latest patient update can actually be found in our February, 2021 by a CEO corporate presentation, which is now on our website. The plan then in GBM is to complete enrollment in the phase one trial this year, as well as complete critical CMC activities by year end or early 2022, such that we would potentially be ready for a phase two pivotal about a year from now, of course, depending on the strength of the data and FDA feedback. Now switching gears and regarding additional clinical development programs for R and L, A priority for us in 2021 is to move additional indications beyond recurrent glioblastoma forward into clinical trials. Although we have promising preclinical data for a number of potential indications, we intend to focus our near-term efforts on two additional CNS indications, leptomeningeal carcinomatosis, which the more modern term that's used is leptomeningeal metastases, and also pediatric brain cancer. Both are two very difficult to treat cancers. LM, leptomeningeal metastases, affects about 110,000 patients in the U.S., and there is no clear standard of care, and these patients die rapidly despite what care we do provide to them. Pediatric brain cancers, though much rarer, carry an equally poor prognosis. The anticipated treatment approach for pediatric brain cancer would mirror our approach in adults with glioblastoma using direct targeting and convection-enhanced delivery. However, LM is a disease of the lining of the spinal fluid space, and nanoliposomes seem to circulate freely if injected there, and preclinical studies thus far look promising. Therefore the delivery approach, which would be an LM direct into the CSF or cerebral spinal fluid, would go typically through an end-dwelling reservoir, which is commonly placed in these patients. Our goal is to have pre-IND meetings with the FDA for both indications in the early part of 2021, understand any gaps that we may currently have in the preclinical data, fill those as needed as rapidly as possible, and then move these into patients, hopefully by near end 2021, if possible. As a final note, and consistent with our stated philosophy of striving for maximum capital efficiency and minimal shareholder dilution in our drug development activities, we intend to apply for state of Texas funding through its CPRIP program whenever possible to help support our development expenditures, as we mentioned previously on other calls. So now with that, let me turn the call over to Andrew for a review of the financial results. Andrew.

Thank you, Mark, 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 full year ended December 31, 2020. At year end 2020, cash and cash equivalents was $8.3 million compared to $17.6 million as of December 31, 2019. Debt principal at December 31, 2020 was 4.3 million, down from 9.3 million at December 31, 2019. In April 2020, we amended our debt with Oxford, providing additional flexibility by pushing out the interest-only period through May 2021 at the earliest, together with a 5 million pay down of principal. In the fourth quarter of 2020, we entered into a purchase agreement and registration rights agreement with Lincoln Park Capital Fund to sell to Lincoln Park up to $25 million worth of shares over the 36-month term of the agreement, subject to various terms and conditions. PLOS will have the right at its sole discretion to sell these shares. In addition, in the fourth quarter of 2020, the company filed a shelf registration on Form S3, allowing for sale of securities at the market of up to $10 million. As previously discussed, Our plan remains to maintain approximately 12 months of go-forward cash or access to cash on the balance sheet, such that we can reliably fund key product development efforts. In addition, we will continue to utilize non-dilutive sources of capital, such as the existing NIH grant that substantially offsets our clinical development costs. We will also continue to be aggressive in seeking further separate and other grants and partnership dollars where able. Cash used in operations for full year 2020 was approximately $8.4 million compared to $5.9 million in 2019. Reported revenues for full year 2020 were $303,000 compared to $7 million in 2019. This decrease was due to the closeout of the BARDA contract as previously disclosed. Research and development expenses were $2.7 million for full year 2020 as compared to $5.4 million for 2019. The decrease was partly attributed to the completion of the BARDA contract in 2019. G&A expense was $6.4 million for full year 2020, as compared to $5.3 million for 2019. The increase reflects an increase in professional fees relating to the recent enlightening transaction announced in 2020, partially offset by a decrease in payroll and related expenses. Interest expense decreased for a full year 2020 to $1.1 million from $1.9 million for full year 2019, reflecting the principal paydowns in 2019 and 2020. Net loss for full year 2020 was $8.2 million, as compared to a net loss of $11.4 million for full year 2019. Net loss in 2019 was impacted by 7.6 million loss from discontinued operations related to the asset divestiture in the second quarter of 2019. And now I'll turn it back to you, Mark. I think you may be on mute, Mark.