Laurence Cooper
Analyst · Raymond James
Thank you, David. And thanks to everyone for joining us today. Let me also thank Director Jim Cannon for his service to Ziopharm. He has provided terrific help and support to me and the company, and we wish him the best. Ziopharm aims to be a leading developer of immunotherapies to target cancers by harnessing the power of our 2 platforms: Sleeping Beauty and Controlled IL-12. I will provide an update on both, beginning with the Sleeping Beauty platform. One of the hottest areas in immunotherapy is centered on the use of T-cell receptors or TCRs, to target neoantigens for the treatment of solid tumors, the leading cause of cancer deaths in the United States. We believe the enthusiasm associated with TCRs today mirrors where CAR-T was several years ago, and we plan to be a leader in the category. So a key question, what sets us apart from others? There's 4 things: first, Ziopharm is focusing on the use of TCRs to target solid tumors as we believe chimeric antigen receptors, or CARs, will have limited commercial appeal. The evidence is that unless the T-cell therapy addresses antigens that are expressed within all of the patient's cancer cells, then that patient will progress or relapse due to the overgrowth of tumor cells that failed to express the targets; second, Ziopharm has developed a solution to enable the cost-effective production of T cells, expressing neoantigens specific TCRs. This is based on the use of DNA plasmids from the Sleeping Beauty system. The simplicity and elegance of this nonviral gene transfer technology sets us apart from the complexity and cost of genetically modifying T cells with virus; third, Ziopharm recognizes that there is currently no off-the-shelf cellular solution to generating T cells that express TCRs. This is because the TCR repertoire needed to address solid tumors, needs to match the number of targeted neoantigens, and in addition, has to match the HLA background of the recipients. If you can't easily swap in and out TCR is targeting a multitude of neoantigens, then you will not be able to fully tackle the tumor which will lead to incomplete responses. Further, if you can't readily swap in and out TCRs representing the HLA background of patients, then you will have difficulty enrolling patients. In other words, there is no CD19 equivalent target for TCRs, in which 1 receptor can be used over and over, justifying the time and expense to manufacture virus and off-the-shelf T cells. Our solution, the Sleeping Beauty system, can be scaled to express multiple TCRs. DNA plasmids enable the desired TCRs to be readily swapped in and out. Of note, to help safeguard against relapse, we anticipate in fusing populations of T cells in the patients that have more than 1 introduced TCR, which further highlights the need for our clinical solution based on DNA plasmids; and fourth, Ziopharm has the most clinically advanced, nonviral, clinical gene transfer technology. Our Sleeping Beauty system has been evaluated in more than 40 patients to date. We have multiyear survivors and contract the presence of CAR-modified T cells for years in some of these recipients. Importantly, we have derisked the Sleeping Beauty System in the CAR-T space, enabling us to soon evaluate this technology for the TCR-T. This contrast with alternative transpose on technologies and other nonviral gene transfer approaches that is just getting going. And we believe, have an uncertain path ahead of them. In summary, we are working with the right team at the NCI, we're targeting the right targets, neoantigens, and with the right tool, the Sleeping Beauty system, to genetically modify patient-derived T cells. At the plenary session of this year AACR annual meeting, Dr. Rosenberg from the NCI highlighted that the advantage of cell therapy in fighting solid tumors will be to administer a large number of T cells that express TCRs for neoantigens. To date, he and his team, in multiple publications, have shown that the Sleeping Beauty system can express TCRs, targeting more than 1 neoantigens. They have shown that these modified T cells can then be grown to numbers needed and as the produced T cells meet anticipated release criteria. We reiterate our plans to initiate a Phase I clinical trial mid-year, in collaboration with the NCI team to treat patients, who have a variety of solid tumors using the Sleeping Beauty platform to genetically modify T cells to target patient-specific neoantigens. David and I, with our respective teams, were recently together at the NCI and the enthusiasm to start this trial is obvious. Turning now to our second program, also built on the Sleeping Beauty platform, is our work on rapid personalized manufacture of CD19 specific CAR-T, which we are now advancing in the United States and in Greater China. The approach is also centered on DNA plasmids from the Sleeping Beauty system, which allows us to genetically modify resting T cells without the need to propagate T cells in a bioreactor. When a CAR is coupled with our proprietary membrane-bound IL-15, we will likely be able to administer small numbers of T cells by comparison to other approaches as our cells will have an embedded cytokine go signal, which is designed to provide a survival advantage for our modified T cells. We also believe that the same go signal may work even in the absence of lymphodepleting chemotherapy, which would infer yet another competitive advantage to our CAR-T program relative to others, especially off-the-shelf therapeutics. Thus, the cost efficiency and the speed of production, coupled with the potential to avoid lymphodepletion, will provide an advantage for our approach in the production of CD19 specific CAR-T. We recognize that last year that there were opportunity to expand on our clinical efforts without CD19-specific CAR outside the United States, and we're very pleased to announce the formation of our joint venture, Eden BioCell, in December. Our partners at TriArm are ideal for this joint venture as they, in Greater China, have strong relationships with front-line physicians and officials at leading hospitals and regulatory bodies. A commitment to conduct high-quality trials and state-of-the-art facilities with good manufacturing practices. The team at TriArm has considerable experience in drug development, including scientific research, clinical and regulatory areas as well as significant laboratory and manufacturing know-how regarding T-cell therapy. Thus, TriArm will manage all clinical development to execute trials in greater China for Eden BioCell. Our teams will be working to map out the best clinical strategy for Sleeping Beauty generated CAR-T therapies in Greater China, and we look forward to sharing our progress with you. Turning to the Controlled IL-12 program. IL-12 is one of the most potent immune stimulators that if correctly administered, can safely lead to profound antitumor effects. We believe that our switch technology provides the precision to safely harness IL-12, which will enable us to turn it into a potent drug. In our clinical studies, we had demonstrated that IL-12 recruits and sustains a significant and long-term inter-tumor T-cell response and enough regulation of immune checkpoint such as PD-1. We recently announced that FDA granted fast-track designation for our Controlled IL-12 program for the treatment of recurrent glioblastoma multiforme in adults. The fast-track program is designed to facilitate the expedited development and review of drugs to serious, life-threatening conditions and demonstrates the potential to address unmet medical needs. In our monotherapy studies, we rapidly completed enrollment and treated a total of 36 patients in a substudy to expand a Phase I trial during the first quarter. All 36 patients were enrolled in less than 6 months and the enrollment exceeded our planned total of 25 patients. We attribute this to the compelling emerging data on overall survival, particularly in patients who received 20 milligrams of veledimex and low-dose steroids. As a reminder, we showed -- we showed data at SNO last November where the median overall survival for that subset of 6 patients reached 17.8 months, which we believe is quite remarkable compared to historical controls of 6 to 9 months. We now have more than 50 patients in cohort, receiving 20 milligrams of veledimex, with the expansion substudy completed. And we expect approximately half of them will have been treated with low-dose steroids. Some of these data will be available at ASCO this year, in a poster presentation. We also have two combination trials of controlled IL-12 with PD-1 inhibitors in our Phase I dose-escalation trials in combination with Opdivo, which began dosing in June of 2018. We have commenced the third quarter now, combining the PD-1 inhibitor with IL-12 and expect to complete enrollment later this quarter. Some of these data will be available at ASCO this year in an oral presentation. These data will continue to mature as more patients are enrolled and as the time and follow-up lengthens. Building on this initial Phase I combination study, we are on track to open in the second quarter of 2019, a Phase II trial to evaluate Controlled IL-12 in combination with Regeneron's PD-1 antibody Libtayo for patients with recurrent GBM. Compared to the Phase I dose escalating trial with multiple cohorts for Opdivo, we expect that the enrollment for this Phase II checkpoint combination trial will be rapid, so we are eager to get started. In summary, for these first few months of 2019, we have worked to build on the momentum of our significant transformation of late last year. We remain steadfastly focused on our near-term goals and another transformation -- transformative year for Ziopharm. And to summarize our key milestones this year include: commencing through NCI a Phase I trial for TCR-T cell therapy midyear; initiating a Phase I trial in the second half of 2019 at MD Anderson and providing data to FDA to lift the clinical hold status; working through Eden BioCell's to advance the Sleeping Beauty platform in Greater China; presenting information from 2 approved abstracts at ASCO next month; and finally, initiating a Phase II combination trial with Regeneron's Libtayo this quarter. And with that, we will turn the call to the operator for your questions.