Marc Hedrick
Analyst · B. Riley. This will be asked by Andrew saying
Thank you very much, David. Good afternoon everyone. Thank you once again for taking the time to join us today as we provide an overview of recent business highlights and discuss our 2021 fourth quarter and full year financial results. Joining me on the call today is Andrew Sims, our Chief Financial Officer. In addition, Joining Andrew and I on the call today for the first time is Dr. Norman LaFrance, our new Chief Medical Officer who joined plus at the end of 2021. We are very excited to have Dr. LaFranceon board as he brings many years of highly relevant clinical regulatory and commercial expertise in radio therapeutics in oncology to the Plus Therapeutics management team. Welcome aboard Norman. I'll begin the call by reviewing our recent corporate and clinical progress before turning the call to Norman who will provide commentary on our clinical expectations for the remainder of 2022. Following Norman, Andrew will review our financials. 2021 and early 2022 has been marked by significant progress as we work toward our mission to become a global leader in developing precision targeted radio therapeutics for cancer. In 2021, we continue to advance our lead investigational targeted radiotherapeutic drug rhenium Rhenium NanoLiposome or RNL in our U.S. ReSPECT-GBM trial. As a reminder, the trial is a dual Phase 1/2 multicenter sequential cohort, open label volume and dose escalation study. The trial is currently funded to a significant degree of the U.S. NCI or National Cancer Institute. Our initial indication for RNL is recurrent glioblastoma with defects approximately 30,000 patients annually in the U.S. and about the same number of patients in Europe. It's the most common and lethal form of brain cancer. And the treatment of this saving disease remains a significant unmet challenge. We call also that RNL is proprietary liposomal encapsulated, radionuclide that is delivered locally regionally via targeted three dimensional convection enhanced delivery. It is administered directly to the tumor, bypassing the blood brain barrier. The activation is the rhenium-186 isotope, which is a dual energy emitter, releasing both cancer killing beta particles, which are high energy electrons, as well as gamma particles, which are useful for imaging, localization and dosimetry. We provided positive interim data from the Phase 1/2 ReSPECT-GBM to the trial in patients with recurrent GBM at the Society for Neuro-oncology Annual Meeting and Education Day, last November. 2021 And then we updated the data set at the BIO CEO conference in New York this month. Both of those presentations can be found now on our website. According to the most recently presented interim clinical data set 186 RNL, delivered via convection enhanced delivery is feasible, up to at least 31.2 millicuries and 12.3 milliliters of volume. No delivery failures were observed. An average absorbed dose of 276 grade of radiation was delivered to the tumors over the course of the trial thus far. Average absorbed radiation to the tumor increased and correlated with dose escalation. In fact, we've shown that we can successfully deliver up to 740 gray, or 20 times the amount of radiation dose one can deliver with traditional external beam radiation in recurrent setting. As an aside about radiation therapy published studies indicate that EBRT external beam radiation provides the best incremental improvement in survival of all therapies currently available for glioblastoma, which is about five months in improve survival. And it remains to this day and a central component of multimodal therapy for GBM and many other cancers. There's no question radiation works in GBM. Furthermore, in ReSPECT trial, key drug delivery parameters such as flow rate, catheter, et cetera, were increased during the course of the trial. And that increase correlated with better drug delivery outcomes and improved overall survival. 186 RNL also thus far well tolerated without those limiting toxicities, has an acceptable safety profile. There were no adverse events, thus far in the trial with the outcome of death, or discontinuation due to adverse events, and placement of up to four catheters in a patient thus far have been safe. As to efficacy, and it's interestingly similar, the efficacy results thus far to our preclinical results and absorb radiation dose of greater than 100 gray in patients it's with increased overall survival. Well, the Phase 1 trial is neither designed or powered for efficacy, we are observing promising signals of both biological effect and increased overall survival. In the latter cohort of the trial specifically cohorts five through eight, receiving greater drug volumes in radiation doses, and frankly more optimized delivery parameters. Nine of the 12 patients are 82% of those patients in cohorts five to eight, received a therapeutic dose of 100 gray are better. And we believe it's entirely possible to achieve a 90% or greater coverage of 100 gray or better bone forward. This far in 23 Total subjects treated in respect with recurrent GBM, the median -- excuse me, the mean and median overall survival for the entire group is currently at 38 weeks and 50 weeks respectively, with seven patients remaining alive. It's interesting to note that in this current trial, which was initiated by the academic physicians back in 2015, it's very unusual have such long-term overall survival data which we do in this trial. Therefore, we take the logical step and take advantage of what's been done by the academics who started the trial and assess a subset of patients who received at least a minimum therapeutic dose of radiation. And as I mentioned, that's greater than 100 gray of radiation. They were treated in the initial five cohorts, which range from the start date of March 2015 through to July 2020, which is longer survival data we have in the trial thus far, immediate and mean overall survival stands at 82 and 88 weeks respectively, the two patients still alive. That compares very favorably with the 32 weeks overall survival published in a recent med analysis, every nearly 700 patients with recurrent GBM treated with Bevacizumab monotherapy in recurrent setting. And that reference can be found on our website in our corporate presentations. Furthermore, our team continues to make excellent progress in drug scale up and manufacturing activities. Specifically during pretty funny one in this by 2022, the company entered into multiple collaboration agreements to support its process development in analytical chemistry activities, as well as to strengthen our supply chain in compliance with GMP practices for planned late stage clinical trials. The company remains on track to deliver GMP 186 RNL in mid-2022. Before I turn the call over to Norman, he will update you on the path forward for 186 RNL. I'd like to highlight the agreement that we announced right at the beginning of January, consummated the end of December. This substantially expands our policy portfolio. As we stated before, we fundamentally believe in the future of cancer therapy is going to be in the precise targeting of tumors with the most potent cancer killing agents while minimizing damage to normal tissues. To that end, we entered into an agreement with the University of Texas for a worldwide exclusive license to develop and commercialize novel interventional therapeutics for cancer. The licensed patents include composition of matter patents for biodegradable alginate microspheres, which we call BAM, containing the nanoliposomes loaded with imaging and our therapeutic payloads. Therapeutic payloads may include radio therapeutics chemotherapeutics, or thermal therapeutics. The BAM technology is delivered into the vascular system via standard interventional vascular technology that are placed precisely in the vessels feeding blood to the tumors. Once injected, BAM both blocks all blood flow to the tumors and simultaneously delivers very high doses of cytotoxic compounds for an extended period of time. Many days later, following full radiation decay, BAM resorbs are physiologically metabolized and then excreted from the body. With this technology, we can target almost any solid organ tumor in the body using standard interventional radiologic methods to leverage the breadth of the human vascular system and deliver a resorbable biomaterial embolic technology coupled with a highly potent radio isotope. The company will initially focus on developing 188 RNL BAM as a next generation radioembolization for liver cancer, in which BAM blocks the hepatic artery segments is supplied blood to the malignant tumor, while also providing 188 RNL radiotherapy and directly irradiating the tumor. Next steps in this program are technology transfer from academia and completing TID enabling CMC and preclinical work. And with that, I'll turn the call over to Norman.