Briggs Morrison
Analyst · Cowen. Your line is open
Thank you very much, Melissa, and thank to everyone for joining us on today's call and webcast. This afternoon, I will share the progress we've made during the second quarter as we continue to execute on our corporate strategy in support of our primary mission – to realize a future in which people with cancer live longer and better than ever before. Slide three provides a summary of the investment highlights for Syndax. During this call, I will discuss both the progress we're making with our lead program entinostat as well as provide some commentary on the clinical development strategy for SNDX-6352, our anti-CSF-1R antibody. I'll review the plans for the upcoming progression-free survival, or PFS, readout from our Phase III entinostat hormone receptor positive breast cancer trial for which received a breakthrough therapy designation from the FDA and I'll review the upcoming milestones related to our exciting ENCORE clinical trial program, which combines entinostat with PD-1 antagonist. Slide four provides a summary of the milestones that we communicated on our last call back in May of 2018. As you can see, we have a lot of definitive clinical data reading out over the next period, a potentially transformative time for our company. Let me now turn to slide five and give you an update on our Phase III trial of entinostat in hormone receptor positive, HER2 negative breast cancer. Slide five summarizes the trial design and the endpoints of the trial. It will also summarize the key upcoming milestones. As we have communicated previously, in the fourth quarter of last year, the ECOG Data Safety Monitoring Committee completed the final progression-free survival analysis and the first interim overall survival analysis of this trial. And these analyses are held confidentially by the ECOG-ACRIN study statistician and the Data Safety Monitoring Committee. No communication regarding this analysis will be released until the completion of enrollment. The trial is now 98% enrolled as of the end of July and we anticipate enrollment completing sometime in the next two months by the end of this quarter. Once final enrollment is achieved, we will learn of the results of the final PFS analysis. And if positive, we are poised to file an NDA within about four to six months of receiving the data from ECOG-ACRIN. We received many questions about what exactly will be communicated at the time of the completion of enrollment. So, to clarify, if the PFS analysis is statistically significantly positive, Syndax will communicate top line results and full data will be presented at an appropriate medical meeting. If the PFS analysis is not met, Syndax will not receive any data from the trial and will simply communicate that PFS was not met and indicate when the next interim OS analysis will be conducted. We will not communicate completion of enrollment. We will communicate the result of the PFS analysis. I'd also like to remind you that the Data Safety Monitoring Committee will examine updated overall survival every six months, generally in May and November. The next interim analysis for overall survival is scheduled for November of this year. Should any of the interim analyses of overall survival show a statistically significant benefit, the trial will end and all data will be released to both ECOG and Syndax. In that scenario, we would communicate top line overall survival results and again full trial results would be presented at an appropriate medical meeting. We remain confident in the potential outcome of E2112 as it's based upon strong Phase II data which led to FDA breakthrough therapy designation. I must say that it's a truly riveting time to be at Syndax. Completing any clinical trial is always extremely gratifying, but finishing a Phase III trial for what could potentially be the next breakthrough therapy for women with hormone breast cancer is simply thrilling. I'd like take a moment to thank the many people who have made this trial a reality. Our colleagues here at Syndax, our colleagues at ECOG and at the many clinical research sites involved in the trial. Perhaps, most importantly, I want to thank the hundreds of women and their families who took part in the trial. We look forward to sharing the results of this landmark clinical trial with the medical and investment community. Slide six emphasizes the potential for the entinostat/exemestane regimen to be the preferred agent after a CDK4, 6 therapy for her HR positive, HER2 negative breast cancer. We know that CDK4, 6 therapies, most notably Ibrance, are being used increasingly as first-line agents, but there's a clear desire to understand what therapies will be effective in a patient who has stopped responding to a CDK4, 6 inhibitor. Our current estimate is that somewhere between 30 and 50% of patients in E2112 will have received a CDK4, 6 inhibitor prior to entering the trial, and thus we will have a highly relevant data set in this population. This population of patients is relatively large with an estimated 34,000 patients who go on to receive hormone therapy after failing first-line therapy and could, therefore, potentially be eligible to receive entinostat. Let me now turn to slide seven, which summarizes our ENCORE clinical trial program, in which we're testing entinostat in combination with PD-1 pathway antagonist, either PD-1 antibodies or PDL-1 antibodies. We are now exploring entinostat in combination with a PD-1 antagonist in six different tumor types – melanoma, non-small cell lung cancer, microsatellite stable colorectal cancer, triple negative breast cancer, ovarian cancer and hormone receptor positive breast cancer. This broad clinical trial program is supported by an extensive cohort [ph] of science program that is designed to identify biomarkers that could predict which patients will experience a clinical benefit from our combination therapy, an effort that, as we have previously communicated, is starting to yield exciting preliminary results. We are extremely encouraged by the results we are seeing across this clinical trial program. As we complete our initial clinical trials in each tumor type, we will prioritize which indications to advance to registration trials based upon unmet medical need, the competitive landscape and our ability to generate an attractive return on our investment. I'm pleased to report that during the first half of this year, we've completed enrollment in two of the three cohorts of ENCORE 601, as well as having completed enrollment in both ENCORE 602 and 603. As I noted previously, we have a lot of definitive data reading out from this program in the coming months. Slide eight is a brief summary of where we are with the three cohorts of ENCORE 601. At ASCO this year, we presented data on the first 57 patients who were treated with a combination of entinostat and pembrolizumab for their non-small cell lung cancer that had progressed on a prior PD-1 antagonist. There will be an oral presentation at the World Conference on Lung Cancer in September of this year on the full 76 patients enrolled in this cohort. That presentation will also provide updated data on the utility of peripheral blood classical monocytes to enrich for patients who derive clinical benefit. As a brief reminder, in the data we presented at ASCO, we saw a 28% overall response rate and a 5.4 month median PFS in the approximately 30% of patients with high peripheral blood classical monocytes at baseline. We expect to communicate our development plans for entinostat in this indication in the fourth quarter. Also at ASCO this year, we presented data on the first 34 patients who were treated with a combination of entinostat and pembrolizumab for their metastatic melanoma who had progressed on a prior PD-1 antagonist or both a PD-1 and CTLA-4 antagonist. Updated data from the full 55 patients in this cohort is anticipated by the end of this year. And as we have previously communicated, we will also be examining the utility of the peripheral blood classical monocytes to enrich for patients who derive clinical benefit in this cohort and anticipate making a decision on our registration plans by the end of the year. Coming out of ASCO, we have not seen any agent that provides a level of efficacy we have seen with the combination of entinostat and pembrolizumab in patients who have progressed on both a PD-1 and a CTLA-4 antagonist. Finally, we also presented data at ASCO this year on 16 patients who were treated with a combination of entinostat and pembrolizumab for their metastatic microsatellite stable colorectal cancer, another area of clear unmet medical need. We expect to complete enrollment of a total of 37 patients in this cohort by the end of this quarter and anticipate making a decision whether to enroll additional patients in the first half of 2019. Slide nine summarizes ENCORE 602 and 603, our Phase II trials in triple negative breast cancer and ovarian cancer. I'm pleased to report that both trials have now completed enrollment and we anticipate topline results from both ENCORE 602 and 603 in the first half of 2019. I want to emphasize that both of these trials are randomized, blinded, placebo-controlled trials that will provide robust evidence on the utility of entinostat in these populations. Positive results from either trial could prove transformational for Syndax and could directly inform the design of potential registration trials in these indications. Again, we're very pleased with the breadth of our ENCORE clinical program and the excitement that has been expressed by physicians who are conducting these important clinical trials. Let me now turn to slide 10 and SNDX-6352, our potential best-in-class monoclonal antibody therapy targeting the CSF-1 receptor. We presented the Phase I healthy volunteer data at SITC in November of 2017 and the multiple ascending dose study in cancer patients is now ongoing. In January of this year, we were very pleased to announce our collaboration with AstraZeneca to study the combination of 6352 with IMFINZI, and that combination trial is now underway. We had previously indicated that we provide an update on our clinical development program for SNDX-6352 around midyear. Given the many competitors who are working on this target, we've chosen to outline aspects of our clinical development program at the time of initiation of specific trial. Today, we're announcing that we have filed a separate IND to study SNDX-6352 for the treatment of chronic graft-versus-host disease, a well described frequent complication of hematopoietic stem cell transportation. This Phase I trial is anticipated to start this year. Slide 11 provides a brief summary of the rationale for developing SNDX-6352 for chronic graft-versus-host disease, a disease in which the pro-inflammatory activity of donor-derived macrophage contributes to the initiation and development of fibrosis and manifestation of many of the advanced disease symptom. Testing and preclinical models of chronic graft-versus-host disease has demonstrated that that blockade of CSF-1, CSF-1R axis with anti-CSF-1R antibodies results in depletion of the pro-inflammatory, pro-fibrotic donor macrophages, thereby preventing and reducing chronic graft-versus-host disease. Based on these data and significant unmet need, we believe that chronic graft-versus-host disease provides an attractive opportunity for testing the safety and efficacy of single agent SNDX-6352 and our trial is the first to test an anti-CSF-1R inhibitor for this syndication. This trial represents an extremely modest investment which we believe, if positive, could unlock significant value for SNDX-6352. It's estimated that upwards of 12,000 patients per year globally suffer from this disease. Last, but certainly not least, on slide 12, we summarize our Menin-MLLr program, which spans a broad range of genetically-defined leukemias and potentially other indications as shown on the slide. We remain on track pending the successful completion of our IND-enabling studies to file an IND in the first half of 2019. Exciting positive data was presented at this year's AACR, demonstrating efficacy against both MLLr PDX models as well as NPM1 mutant PDX models, and those presentations can be found on our website. I want to emphasize that we see a rapid and straightforward clinical development path for our Menin-MLLr inhibitor. The molecule is anticipated to have single agent activity. We will, of course, target patients who have an MLLr rearrangement. It's quite possible that we could observe clinical activity very early in the clinical development path, again unlocking significant value for Syndax. So, really, stay tuned on this program. And with that, I'll turn it over to Rick for the financial update.