Briggs Morrison
Analyst · Cowen
Thank you, Melissa, and thanks to everyone joining us on today's call and webcast. This afternoon, I'll share the progress we've made during the first 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 briefly summarizes our corporate strategy, which includes developing three potential best-in-class molecules, entinostat, SNDX-6352 and our Menin-MLL-r portfolio, which are being tested at five ongoing clinical trials across six different indications. An additional important component of our corporate strategy is the opportunistic in licensing or acquisition of products that have both a compelling strategic fit and potential return on our investment. Slide our provides a summary of the investment highlights for Syndax. During this call, I will primarily focus on the progress we're making with our lead program, entinostat. I will discuss both our Phase III trial for breast cancer, which we received breakthrough therapy designation from the FDA, as well as our exciting ENCORE clinical trial program, which combines entinostat with PD-1 antagonist. Slide five provides a summary of the milestones we communicated on our last call back in March. I will say more about the abstracts we were representing at ASCO later in my comments and I will note that we now anticipate topline results from ENCORE 602 in the first half of 2019. Let me now turn to slide six and give you an update on E2112, our Phase III trial of entinostat in hormone receptor positive HER2 negative breast cancer. Slide six summarizes the trial design and endpoints. We will also summarize the key upcoming milestones. As we communicated previously, in the fourth quarter of last year, the ECOG Data Safety and Monitoring Committee completed the final progression free survival or PSS analysis and the first interim overall survival or OS analysis of this trial. And these analyses are held confidentially by the ECOG-ACRIN study statistician and the Data Safety and Monitoring Committee. No communication regarding this analysis will be released until the completion of enrollment. We recently learned that the ECOG data safety monitoring committee has now also completed the second interim overall survival analysis of the trial and the trial is now 90% enrolled as of the end of April. We anticipate enrollment completing sometime in the third quarter of this year, and we'll continue to update you about the precise timing of completion of the trial as its final enrollment progression. Once enrollment is completed, we will learn of the results of the final PFS analysis and if positive, we're poised to file an NDA by the end of this year. We received many questions about what exactly will be communicated at the time of completion of enrollment. And so just to clarify, if the PFS analysis is statistically significantly positive, Syndax will communicate topline results and present full data in an appropriate medical meeting. If the PFS analysis is not positive, Syndax will not receive any data from the trial and will simply communicate that PFS was not positive and indicate when the next interim OS analysis will be conducted. Indeed, I'd like to remind you that the Data Safety Monitoring Committee will examine updated overall survival every six months, generally, in May and November. Should any of the interim analysis of overall survival show a statistically significant benefit, the trial will end and all data will be released to ECOG and Syndax. We will begin communicating top line results and present full results at appropriate medical meeting. We remain confident in the potential outcome of E2112 given that it's based upon strong Phase II data, which led to FDA breakthrough therapy designation. Slide seven emphasizes the potential for the entinostat exemestane regiment to become the preferred agent after a CDK4/6 therapy for homosexual [ph] positive HER2 negative breast cancer. We know that CDK4/6 therapies most notably high brand [ph] are being used increasingly as first-line agents, but is a clear desire to understand what therapies will be effective in a patient where it's stop responding to CDK4/6 inhibitor. Our current estimate is that between 30% and 50% of patients of 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. And importantly, as shown on slide seven, we have tested entinostat in 3 distinct preclinical models of palbociclib resistance and have found no cross resistance with entinostat. That is the median effective dose of entinostat in these model systems is the same whether or not the cell line is resistant to palbo. This preclinical data suggests that the fact that patients have received a CDK4/6 inhibitor prior to entering E2112 should not affect the ability of entinostat to provide a clinical benefit. Together, we believe these data uniquely position entinostat to be the preferred agent after CDK4/6 first-line therapy. Slide eight makes the same point and notes that this population of patients is relatively large, with an estimated 34,000 patients who go on to receive formal therapy after failing first-line therapy and could, therefore, potentially be able to receive the entinostat exemestane regiment. Let me now turn to slide nine, which summarizes our exciting ENCORE clinical trial program, in which we are testing entinostat in combination with PD-1 pathway antagonists, either PD-1 antibodies or PD-L1 antibodies. We are now exploring entinostat in combination with 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 coral 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 is starting to yield exciting pulmonary results. We are extremely encouraged by the results we're seeing across this clinical trial program and 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. Slide 10 is a summary of where we are with our program in melanoma. We presented the initial cohort of 13 patients at ASCO in 2017, where we saw a 31% response rate. Based upon continued discussions with melanoma physicians, it's clear that a response rate of about 20% or greater would be considered highly clinically relevant especially in patients whose disease has progressed after receiving both a PD-1 antagonist and a CTLA-4 antagonist. Given the tremendous enthusiasm with this combination from our investigators, we've allowed continued enrollment in this cohort of patients and have now enrolled a total of 55 patients. We'll present an update on this cohort at ASCO. Given that we have now conducted our regulatory consultations and a number of advisory boards with physician’s experts in melanoma, we will be providing details on our registration strategy sometime later this quarter. Slide 11 is a summary with where we are the program in non-small cell lung cancer. We presented the initial cohort of 31 patients whose disease had progressed out of PD-1 antagonist at SITC in November of 2017. The response in that cohort was 10% and we've continued to receive very strong feedback from physicians participating in this trial. As I noted earlier, we're making exciting progress with our extensive cohort science size program designed to identify biomarkers that could enable us to enrich for patients who derive clinical benefit as we design future clinical trials. We've allowed continued enrollment in this cohort to aid in our biomarker discovery effort and have now enrolled a total of 76 patients. An update on this cohort will also be presented at ASCO. ASCO abstracts will be released next week on May 16. It's important to note that these abstracts were submitted in early February with the data cut off as of late January and I want to emphasize that our non-small cell lung cancer abstract has no information about our biomarker work. That work has just come together in the past couple of months. Data from the biomarker analysis will be included in our poster and we're excited about this new data and look forward to sharing it with you. Slide 12 highlights two points. The first is that biomarkers are routinely used today to select the most appropriate therapy for patients with non-small cell lung cancer. Outside of immuno-oncology, tests for EGFR mutations and ALK reenactments are now routine, and they're a number of commercially successful therapies that are specifically used for patients with these genetic. KEYTRUDA, of course, is indicated as monotherapy for newly diagnosed non-small cell lung cancer patients with high PD-L1 expression. And BMS recently communicated that tumor mutational burden may be a marker to select newly diagnosed patients who benefit from the combination of Opdivo and YERVOY. So based upon this established approach to treating non-small cell lung cancer, we are focusing our efforts on developing a patient selection strategy that will enable us to enrich for a specific publishing of patients as we progress development of entinostat in non-small cell lung cancer. The second point is that the treatment paradigm for non-small cell lung cancer is becoming clearer as a number of Phase III trials have read out. The data from our keynote 189 trial suggests that all patients regardless of PD-L1 status may derive a benefit in terms of overall survival when treated with KEYTRUDA plus chemotherapy compared with platinum-based chemotherapy alone. And data would suggest that the chemo 189 regiment will increasingly be used in the first line setting. Once you know, however, that in keynote 189, roughly 80% of patients have progressed with an 18 months of starting therapy and these patients are today treated with standard single agent or combination chemotherapy. We believe there is a large and growing unmet need in this population of patients for improved therapy. Slide 13 is a summary of where we are with our program in colorectal cancer. We completed enrollment of the first cohort of patients at the end of the third quarter last year and are continuing to monitor these patients, we'll presented data on that cohort at ASCO. However, in collaboration with Merck, we have modified the Simon II stages design for colorectal cancer. Initially, this cohort was designed with 13 patients in stage 1 and a criterion to have at least 2 responses in order to move into stage 2 and then enroll a total of 34 patients. That design was based upon a prudent response rate of 25% for the overall cohort. As we noted in our last call, based upon continued discussions with physicians that are expert in the treatment of colorectal cancer, it's clear that a response rate of even 15% would be highly clinically relevant in this population of patients. So therefore, modified the Simon two-stage design to test for a proactive response rate of 15%. We will thus enroll a total of 37 patients in stage 1 and if we see at least 3 responses, we'll proceed to stage II and enroll an additional of 47 patients for a total of 84. We will commence enrolling this modified stage 1 cohort later this quarter and anticipate making a go no go decision to advance to stage II in the first half of 2019. I should also again emphasized that we're exploring a number of biomarkers in this cohort with the goal of again, finding a way to retro [ph] patients who derive clinical benefit. Slide 14 makes the point that microsatellite stable colorectal cancer represents a significant market opportunity for entinostat if we can demonstrate efficacy in this clinical setting. Slide 15 summarizes ENCORE 602 and 603, our Phase III trial for triple negative breast cancer and ovarian cancer. I'm pleased to report that ENCORE 603 has completed enrollment and ENCORE 602 should complete enrollment this quarter. We now anticipate top line results from both ENCORE 602 and 603 in the first half of 2019. So again, we're very pleased with the breadth of our ENCORE clinical program and the excitement we are sensing from physicians who are conducting these important clinical trial. Let me now turn to slide 16 and SNDX-6352, our potential best-in-class monoclonal antibody targeting the CSF-1 receptor. We presented the Phase I healthy volunteer data at SITC in November of 2017, and the MAD study cancer patients is ongoing. In January of this year, we were very pleased to announce our collaboration with AstraZeneca, to study the combination of 6352 with infinze. Initial work focused on safety of this domination is expected to begin this quarter and we've now designed a very focused clinical development program for this molecule and we'll say more about that later this year. Slide 17 summarizes our Menin-MLL-r program, which fancied broad range of leukemias and potentially other indications as shown on the slide. We remain on track to file an IND in the first half of 2019. Data was presented at AACR regarding demonstrated efficacy both in MLL-r PDX models, as well as in MPM 1 mutant PDX model. And these presentations can be found on our website. Slide 18 summarizes how the transactions that we completed to acquire both SNDX-6352 and the Menin-MLL-r programs prove that we have ability to strategically expand our pipeline. Our management team and board have established relationships that allow us to identify quality assets and the extensive clinical development and experience of our team gives us a competitive advantage in closing agreement. We continue to expand significant efforts in this area and we consider this capability to be a core strength of our customers. On Slide 19, we summarized the data that will be presented at ASCO and we look forward to seeing many of you there in Chicago. And with that, I'll turn it over to Rick for the financial update.