Briggs Morrison
Analyst · BTIG. Your line is open
Thank you very much Melissa and thank you to everyone for joining us on today's call and on the webcast. Slide 3 provides a high level summary of our current corporate priorities. As you progress through this year, we continue to focus our resources on two incredibly exciting opportunities. The first is we are anticipating a positive readout of E2112, our Phase 3 trial of entinostat in hormone receptor-positive breast cancer; and a subsequent filing of our first NDA and the corresponding launch of our first product. I want to again emphasize that our positive overall survival trial in hormone receptor positive HER2 negative breast cancer would be a landmark result and would be transformative for Syndax, its shareholders but most importantly for patients. We believe the entinostat opportunity in hormone receptor positive breast cancer carries blockbuster potential. The E2112 Data Safety Monitoring Committee recently completed their scheduled second quarter interim analysis and has informed us that the trial will continue as planned. This result is encouraging and consistent with our base case assumption. We will now turn our attention to the upcoming fourth quarter 2019 analysis. I'd also like to take a moment to congratulate Dr. Roisin Connolly on behalf of everyone here at Syndax for winning the ECOG-ACRIN Young Investigator Award this past Friday. As you may know, Roisin is the lead investigator for E2112 and we appreciate all the work that she's done to make E2112 a successful endeavor. Second, we remained on track to file an IND this quarter for SNDX-5613, our potential first and best-in-class menin targeted agent for the treatment of mixed lineage leukemia followed by the rapid initiation of our broad clinical program in acute leukemia. As we continue to learn more about the potential of 5613 in acute leukemia, we see this molecule becoming another important value driver for our company. We believe that the breadth of indications we will investigate with 5613 represents a second blockbuster opportunity. Now let me review these opportunities in a little more detail. Slide 4, summarizes the design of our Phase 3 trial of entinostat in hormone receptor positive HER2 negative breast cancer. The trial has randomized 608 patients to either exemestane plus placebo versus exemestane plus entinostat, and the focus of this trial is now clearly on overall survival. As we've noted before, overall survival interim analyses are conducted approximately every six months and positive outcome at any of the OS interim analysis or upon achieving the final number events needed to conclude the study would allow us to file for regulatory approval based upon the terms of our breakthrough therapy designation in hormone receptor metastatic breast cancer and a special protocol assessment process we went through with the FDA. The Data Safety Monitoring Committee recently informed us that based upon the second quarter interim analysis the trial passed a formal futility analysis and continue as planned. I like to remind everyone that each interim analysis evaluates both the possibility that the trial is futile through a formal futility analysis at each interim, as well as the possibility that the trial is positive based on a statistically significant improvement in overall survival. So we are pleased that the trial has not stopped for futility and we remain confident that the trial will be positive. The final analysis of this trial will be conducted once there are 410 survival events. We don't know when the 410th event will occur, but based upon the modeling we've done, we believe the final analysis could occur in November of this year or possibly in May of 2020. Slide 5 emphasizes the potential for the entinostat-exemestane regimen to be the preferred agent after CDK4/6 therapy for hormone receptor positive HER2 negative breast cancer representing a blockbuster market opportunity. We know that CDK4/6 therapies, most notably Ibrance, are being used increasingly as first-line agents, there's a clear unmet need for therapy that will be effective in a patient who has stopped responding to a CDK4/6 inhibitor. Our current estimate is that between 30% and 50% of patients in E2112 will have received a CDK4/6 inhibitor prior to entering the trial, and that's we will have a highly relevant dataset in the post-CDK4/6 patient population. This population of patients is substantial with an estimated 34,000 patients each year who go on to receive hormone therapy after failing first-line therapy and who could therefore be eligible to receive the entinostat regimen. We're also of course quite excited about the upcoming IND filing for our genetically-targeted agent 5613. Slide 6 shows the similarity between our menin program and other medicines that have attacked fusion proteins that are a result of chromosomal rearrangements. The first example of a recurring chromosomal rearrangement in oncology was the so-called Philadelphia chromosome, which results in the BCR-ABL fusion protein, and which led to the development of gleevec and other BCR-ABL inhibitors. Since then, there have been many examples of medicines that specifically attack such fusion proteins that result from a chromosomal translocation, including medicines against EML4-ALK fusions, NTRK fusions and RET fusions. In these chromosomal translocations, there were strong evidence that the resulting fusion protein is driving the cancer cell. Being able to precisely define these patients led to the development of medicines that demonstrate large treatment effects in specific patient populations and enabled a rapid clinical developments and regulatory path. I want to emphasize that our 5613 program is an example of a targeted therapy that was designed based upon our understanding of a specific chromosomal rearrangement that leads to a specific fusion protein known to drive the leukemic process. On Slide 7, we summarize the status of this program. The IND is on track to be filed later this quarter, with the Phase 1/2 clinical program to begin soon thereafter. Once the IND is approved, we'll be able to provide the final details of our Phase 1/2 clinical program. However, we can say that our goal is to enroll adults with MMLr Leukemias followed by children with MMLr Leukemias. And we also intend to enroll adults with NPM1 mut leukemia based upon the very compelling preclinical data that was presented at ASH this past December, which showed that 5613 has promising activity in that disease as well. Again, I want to emphasize that we see a rapid and straightforward clinical development path for 5613 similar to the path taken for patients with NTRK fusions or IDH1 mutations. We expect that the molecule should have single agent activity and it's quite possible that we could observe clinical activity early in the clinical development path, again unlocking significant near-term value for Syndax. As we continue to learn more about the potential of 5613 in acute leukemia, we see this molecule becoming an additional and important value driver. Let me now briefly turn to our entinostat ENCORE clinical trial program, in which we evaluated entinostat in combination with PD-1 pathway antagonists. I will remind investors that the ENCORE program was set up as a signal-seeking program exploring multiple tumor types with different immunologic characteristics. We've also look for biomarkers that could predict clinical benefit. Slide 8 shows that the immunologic environment is quite variable in different tumors. The ENCORE results today indicate that the beneficial effect in entinostat is strongly evident in inflamed tumors but not in the other immunologic settings. We believe this is an important conclusion of our work. Slide 9 summarizes our findings recently presented at AACR, consisting with prior data we see a strong signal of clinical benefit when entinostat is combined with KEYTRUDA in patients with non-small lung cancer patients, who's decease has progressed after both chemotherapy and a PD-1 antagonists. We've also identified a biomarker, peripheral blood class O monocytes that appears to predict clinical benefit in this population of patients. In addition, we've seen a strong and durable clinical benefit when entinostat is combined with KEYTRUDA in patients with melanoma, whose disease has progressed on after both PD-1 inhibitor and a CTLA-4 inhibitor. We're especially encouraged by the positive feedback we've received from therapeutic area experts and investigators, who like us recognize the potential of this combination to deliver a clinically meaningful benefit to patients who are currently lack alternative options. As we discussed on our last quarterly call, following the availability of positive E2112 OS results, we will determine whether to advance the entinostat-PD-1 combination programs into one or more registration trials. Let me now turn to turn Slide 10 in SNDX-6352, our potential best-in-class monoclonal antibody targeting the CSF-1 receptor. We initiated a trial testing in chronic graft versus host disease in the fourth quarter of last year. Chronic graft versus host disease is a frequent complication of hematopoietic stem cell transplantation, wherein the donor derived immune cells contribute to the initiation and development of fibrosis and manifestations of many of the advanced disease symptom. In preclinical models, blockage of the CSF-1 pathway with anti-CSF-1R antibodies can result in the depletion of donor macrophages, thereby preventing and reducing chronic graft versus host disease. We believe that chronic graft versus host disease represents an attractive opportunity and we look forward to sharing initial efficacy data in the second half of this year. Finally Slide 11 summarizes how the many transactions that we have completed to acquire both SNDX-6352 and the Menin-MMLr programs prove that we have an ability to strategically expand our pipeline. Our management team and board have established relationships that allow us to identify quality, differentiated assets, and the extensive clinical development experience of our team gives us a competitive advantage in closing agreements. We continue to expend significant efforts in this area, and we consider this capability to be a core strength of our company. I'd like to now turn the call over to Michael Metzger, our President and Chief Operating Officer to discuss our recent financing. Michael?