Aptose Biosciences, Inc.

Welcome to the Aptos Biosciences Incorporated reports result for the first quarter 2022 conference call. My name is Darrell and I'll be your operator for today's call. At this time, all participants are in listen-only mode. Later, we will conduct a question and answer session. During the question and answer session, if you have a question, please press 01 on your touchtone phone. As a reminder, this conference is being recorded. I will now turn the call over to Dan Ferry. Dan, you may begin.

Thank you. Good afternoon, and welcome to the Aptos Biosciences conference call to discuss financial and operational results for the first quarter ended March 31st, 2022. Earlier today, Aptos issued a press release relating to these financial results. The news release, as well as related SEC filings, are accessible on Aptos' website. Joining me on today's call are Dr. William G. Rice, Chairman, President and CEO, and Dr. Rafael Bejar, Senior Vice President, Chief Medical Officer. Before we proceed, I would like to remind everyone that certain statements made during this call will include forward-looking statements within the meaning of US and Canadian securities laws. Forward-looking statements reflect Aptos' current expectations regarding future events, but are not guarantees of performance. And it is possible that actual results and performance could differ materially from these stated expectations. They involve known and unknown risks, uncertainties, and assumptions that may cause actual results, performance, and achievement to differ materially from those expressed. To learn more about these risks and uncertainties, please read the risk factors set forth in APTOS's most recent annual report on Form 10-K and SEC and CDER filings. All forward-looking statements made during this call speak only as of the date they are made. Aptos undertakes no obligation to revise or update the statements to reflect events or circumstances after the date of this call, except as required by law. I will now turn the call over to Dr. Rice, Chairman, President, and CEO of Aptos Biosciences. Dr. Rice? Thank you, Dan.

I want to welcome everyone to our call for the first quarter ended March 31st, 2022. Because our last call was only a month and a half ago, and because we plan to hold a KOL corporate update event around the European Hematology Association, or EHA, conference in just a few weeks, today we'll provide you with a brief update. Today I want to emphasize that Aptos is in the best position in which we've ever been, with two well-differentiated, well-tolerated, and active kinome inhibitor drugs, HM43239, or just 239, and Luxeptinib, or Lux as we call it. We continue to thoughtfully execute on our corporate vision, and we're entering a new stage of maturity. In fact, our chief medical officer, Dr. Rafael Behar, will discuss why we believe our lead candidate, 239, is a best-in-class oral kinase inhibitor designed to treat the disease of AML, not just treat a particular target, and is superior to competitors for the treatment of AML patients with adverse mutations. And LUX, which is mechanistically and preclinically remains a well-differentiated agent, has demonstrated clinical activity in B-cell and AML cancers. Plus, we continue to make strides with a new formulation with LUX in an effort to achieve greater plasma exposures with lower doses of LUX. And we recently highlighted its activity on the NLRP3 inflammasome and potential application to inflammatory and autoimmune diseases. Again, Dr. Behar will deliver the updates on both product candidates. But before I turn the microphone over to him, I want to make a few remarks about 239, about the upcoming EHA conference, and about our new chief commercial officer. Let's begin with 239. A timely event to highlight is our recent news that the FDA has granted fast-track designation to 239 for the treatment of patients with relapsed or refractory AML who have FLT3 mutations. 239 previously had received orphan drug designation from the FDA for the treatment of AML. And the designation of fast-track status certainly is welcome news as it codifies the recognition that 239 already has demonstrated meaningful clinical benefit to FLT3 mutated AML patients. As most of you are aware, fast-track status acknowledges 239's potential to fill an unmet need for AML patient populations and supports our efforts as we advance it towards a potential registrational study. The FAST-TRACK designation also helps facilitate and potentially expedites the drug's development, which allows us to have early and frequent communication with the FDA so that questions and issues are resolved more quickly. Now let's discuss our plans for the upcoming eHOP conference that is just a few weeks away. We recently were notified that an abstract we submitted to eHOP encompassing preclinical research on 239 has been accepted for a poster presentation in Vienna. But just prior to EHOP, we plan to hold a KOL corporate event, during which we plan to present available clinical data from all patients and all dose levels enrolled in our clinical trials for both 239 and LUX. We will continue to collect PK, PD, efficacy, and PET scan data up until the time of the KOL corporate event, and such data will not be embargoed. For LUX, we also plan to update you on the clinical data with our new G3 formulation in AML and B-cell cancer patients. Data from patients receiving G3 will continue being collected over the next few weeks, and we plan to present the available data at the KOL corporate event. Regarding 239, regard that during the ASH conference in December, we presented five complete remissions, or CRs, with the 80-milligram cohorts. four of which advanced to the potentially curative allogeneic stem cell transplant. In addition, one patient who was unfit for transplant harbored wild-type FLT3 and a highly adverse TP53 mutation. This patient experienced a durable response, including a CR, for more than one year. These data illustrate that 239 meaningfully and safely extended the life of multiple patients with relapsed or refractory AML that already had been failed by other therapies. More recently, we reported that at the 120-milligram dose, that one patient had experienced a partial remission, or PR, and another patient with MLL and RUNX1 mutations experienced a complete remission, or CR, adding to the CRs from the 80-milligram dose level reported in December. Consequently, we already have identified two dose levels. 80 milligram and 120 milligram that pair complete remissions with tolerability. And we now are exploring a higher dose by expanding at the 160 milligram dose level. By methodically testing different doses with numerous patients during this phase one trial in a disciplined manner, we optimize our chance to select the best doses to maximize safety and to minimize regulatory risk by avoiding a dose that could exhibit toxicity. Also, I want to be clear that as we approach EHOP, our focus with 239 now is to recruit AML patients with a diverse array of mutations in our ongoing phase one trial. We already have demonstrated CRs in multiple patients with FLT3 mutated AML, and the FDA has recognized that capability by awarding Aptos with fast track designation for 239 in these patients. However, we are not attempting to focus solely on FLT3 mutated patients in this trial. This is a phase one trial designed to explore doses and the range of activity of 239. Because we also have seen CRs in patients with wild type FLT3 and a host of other adverse mutations, we want to further our understanding of the full breadth of activity of 239 in patients with diverse mutation profiles. While this may result in a lower percentage of CRs in the near term, in patients with adverse commutations, we believe this approach should allow us to select the appropriate populations to treat and those populations to avoid in future studies as part of our goal to deliver the greatest value to patients, physicians, and the investors. To be clear, our focus is to select genetically defined AML patient populations with unmet medical need that appear to have sensitivity to 239. and then to initiate fixed-dose expansion trials in these patient populations. The first step is to identify the appropriate patient populations, and we believe the ongoing Phase I trial already is delivering this information. Second, for these expansion trials, we must identify an efficacious and well-tolerated dose at the selected expansion or go-forward dose. In fact, the ongoing Phase I already has identified at least two go-forward doses that are both safe and efficacious that we can use to explore and optimize in our expansion trials in specific patient populations. In the second half of the year, we plan to present the selected expansion dose along with the safety and efficacy packages to the FDA and request allowance to initiate the expansion trial soon thereafter. If data from those trials are sufficiently compelling, we then would request an accelerated registrational pathway Of course, this is the desired path for 239. There is much work ahead of us, but 239 today has delivered results that point us in this direction. We plan to speak more about this plan during the KOL corporate event. As an FYI, we plan to announce formally the KOL corporate event and its logistics later this week, along with the EHA abstract. Now let me turn to my last subject. With the maturation of the company's products, comes to the task of building the right team. And so I'm very pleased that we recently added a chief commercial officer, Dr. Philippe Ledru, to our executive management team. Philippe comes to Aptos with exceptional pharmaceutical industry experience in the U.S. and Europe. Most recently, he served as associate vice president and head of oncology new products at Merck, where he was responsible for commercial leadership over the Merck oncology pipeline, over 25 assets from discovery to mid-stage clinical development across major solid tumors and hematologic malignancies. At Merck, he also provided commercial leadership on all licensing and M&A activities, including the Peloton Therapeutics and Arcul acquisition in 2019. Prior, Dr. LeDrew spent a 20-plus year career at Novartis in the U.S. and France, most recently a senior director of early commercial strategy focused on oncology products. There, he also was a member of the brand team, and he held early commercial development and global marketing responsibilities for several new compounds, including the FLT3 inhibitor imatastorin. Earlier at Novartis Oncology, he helped lead the launches of several oncology products, including the kinase inhibitor imatinib, brand name Gleevec, a landmark drug pioneered by Dr. Brian Druker that has transformed outcomes for patients with chronic myelogenous leukemia. Prior to Philippe joining Aptos, our drug 239 lit up on his radar screen of priority agents, and he actually approached us with his interest in joining Aptos to work on the development and commercial strategy for 239. Need I say more about what a timely fit he is for Aptos, and we're delighted to have him join our team. With that, let's have Dr. Behar give us a brief commentary on 239 and LUX. Raph?