Richard Ghalie
Analyst · Laidlaw & Company. Please go ahead
Thank you, David. And I'll begin first by discussing voruciclib, a selective oral CDK9 inhibitor drug candidate. The mechanism of action of voruciclib is depicted in this cartoon. Voruciclib blocks the transcription of MCL-1 and MYC at the pol II level DNA transcription. In addition, voruciclib block the stabilize -- includes the stabilization of the MYC protein which has a downstream effect on that pathway. In a moment I will give more detail to the meaning of these two targets. Voruciclib has a favorable PK and PD profile that allow its use orally because it's bioavailable. It is selective to CDK9 compared to other CDK, as shown on the table to the right, with a more binding affinity and longer resonance time for CDK9 compared to the other CDK. In addition, voruciclib had more selectivity to CDKs compared to other kinase. Voruciclib is potent with an IC50 ranging from 0.2 to 1.7 micromolar in a variety of cell lines tested and interestingly it concentrates in tumors over plasma, which is relevant in patients with solid tumors or lymphoid malignancies with tumors. Now let's focus on the two targets of interest. The protein MCL-1, it is known that its increase is associated with poor prognosis in patients with acute myeloid leukemia or AML and in a variety of B-cell malignancies. In addition, upregulation of MCL-1 is an established mechanism of resistance to venetoclax. As venetoclax inhibits BCL-2, it can lead to stabilization of MCL-1, leading to resistance to venetoclax over time. Independently and separately, we also know that MYC is overexpressed in a variety of cancers and tend to be associated with poor prognosis. In addition, the MYC pathway includes KRAS mutation, which will be relevant for the discussion about the potential role of voruciclib. Let's begin first on the aspect of inhibition of MCL-1. As mentioned, it is relevant for AML and B-cell malignancies and as a way to address venetoclax resistance. MEI focused its initial development in hematologic malignancy beginning with AML. The reason we selected AML is because venetoclax-based therapies are standard of care and approved in elderly patients who are unfit to receive intensive chemotherapy. In the NCCN guidelines, it's been established also as the standard of care in a variety of market research, including the one cited on the right. In addition, ongoing studies are being conducted to establish the role of venetoclax as part of the standard of care in chemotherapy-eligible patients. Our hypothesis is voruciclib combined to venetoclax has the potential to restore sensitivity to venetoclax and therefore improve durability of response. This slide summarizes the non-clinical data that support the combination of voruciclib and venetoclax in AML. This is a murine xenograft model. In panel A, it shows suppression of MCL level. In panel B, it shows that either agent alone has activity in AML, but the combination is synergistic with further increase in apoptosis level. And that corresponds to an improvement in survival in the model depicted here in AML. We have similar data with a combination with venetoclax and CLL and diffuse large cell lymphoma models. Now moving to describe the Phase 1 study. This is a typical Phase 1 dose escalation expansion study in patients with relapsed refractory AML and B-cell malignancy in the first stage, which is the monotherapy dose escalation, and in patients with relapsed and refractory AML for the combination with venetoclax stage. As for Phase 1 studies, its endpoints consist of safety, pharmacokinetic. We are also collecting sample for biologic correlate, primarily to look at DHC profiling and MCL-1 expression, as well as molecular mutation analysis. And we will also collect, of course, activity data. The monotherapy dose escalation component has been completed with 40 patients enrolled, and we are now currently enrolling in the combination with venetoclax group and patient with AML. As mentioned, this is a two-stage component. First, a dose escalation going from 50 milligrams every other day upward. And as of now, we have completed enrollment at the 150 milligram dose level. Once a dose that is confirmed to have well tolerance as well as evidence of activity, then we will proceed to expansion cohort. Currently there is one contemplated and additional expansion cohort will be discussed with the FDA. In total, the study will enroll over 100 patients with hematologic malignancies, including approximately 70 patients in the combination with venetoclax. This is a brief summary of the data observed in the [indiscernible] escalation. Primary data was presented at the ASH 2021, and additional data and final data was presented at some subsequent scientific meeting. In total, 40 patients were enrolled, all heavily pre-treated with a median of three prior therapy ranging from one to up to eight therapies in one patient. Two of those schedules were evaluated initially daily continuously in 16 patients. And we have at that time pivoted to evaluate voruciclib on a 14 days on, 14 days off therapy in a 28 day cycle. And the reason for this pivot is because we have seen in the daily dosing two patients pneumonitis that we felt were confounded by patient having developed differentiation syndrome, seen in AML patients receiving target therapy, as well as prior allogeneic transplant with [indiscernible] disease. When we switched to the two weeks on, two weeks off schedule, we were able to dose escalate up to 200 milligrams without seeing DLTs. We stopped those escalation not because of safety reasons, but because we wanted to start pivoting to the combination with venetoclax, our target combination regimen. With the monotherapy, we have seen patients having evidence of anti-tumor activity, including one patient with AML who has a morphology leukemia-free state achieved, and five of 10 patients with AML at the 200 milligram dose who have stable disease. Importantly, we have seen in our collaborative laboratory studies done with collaboration at academic centers, a decrease in MCL-1 and MYC using a single-cell RNA sequencing from three patients with CLL and two patients with AML. So overall, voruciclib as a monotherapy at a dose of up to 200 milligram on a 14 days on, 14 days off schedule, was well tolerated, had no DLT, we did not see drug-related neutropenia, we did not see Grade 3 or higher drug-related toxicity, and no patients were discontinued due to drug-related toxicity. As mentioned, we are now enrolling in the venetoclax combination. Up to now, we have not seen DLTs. The PK analysis of the earlier dose level do not show drug-drug interactions, and we are seeing evidence of clinical activity at the low dose evaluated today, manifested by a reduce in transfusions, improved counts, response observed in some patients, and over 85% of the patients continuing beyond cycle 1 of the DLT windows. Keep in mind, this is observed in patients who have been heavily pretreated with a medium of two prior therapy, including venetoclax. Now let's turn the focus to the recycling effect on MYC. As mentioned, MYC is over expressed in a variety of cancers and tend to be associated with poor prognosis. There is no current treatment approved for MYC mutated tumors. CDK9 inhibition lead to reduce transcription of MYC and stabilization, thus can have a potential treatment effect. We have clinical data from initial studies conducted in patients with solid tumors by the prior sponsor. Two studies were conducted, one using a two weeks on, one week off schedule, and the other one using a daily continuously schedule. Relevant to the discussion today is in the daily continuous schedule study, samples were obtained from 25 patients with a variety of solid tumors and tested on a 10 gene biomarker with a sample obtained at baseline and with each subsequent course of therapy. We have seen a decrease in c-MYC expression in 60% of the patients tested in that study. And here are shown only two illustrative examples of two patients. Circled are the MYC gene that were evaluated showing a decrease in MYC over time with each course of therapy. At MEI, we have further expanded the evaluation of that effect on MYC and KRAS by evaluating a number of cell lines listed here, including colorectal cancer and other tumors, that had a variety of KRAS mutations, G12C, but also others. And shown to the panel to the right is a dose response relationship between voruciclib dose and suppression of tumor growth in three different cell lines with different KRAS mutations. And lastly, and of interest, is combination of voruciclib with the KRAS inhibitor, sotorasib. This experiment was conducted in a pancreatic tumor cell model. This is intralesional infusion of one or a combination of drugs. And the readout is shown to the panel to the right where we see two type of analysis. One is the standard pathology with an HA staining that shows the control arm, either agent alone, and to the bottom right panel, the combination, showing evidence of cell death, pyknotic cells, and also in the fluorescent staining, an increased number of cells dying. So that is my summary for the voruciclib program. Now I'm turning to the description of ME-344, a mitochondrial inhibitor drug candidate. This is a very interesting and novel mechanism of action where the inhibition on the mitochondria is a dual effect. One, on OXPHOS, and two, on purine synthesis, reminding that purine synthesis is made at the surface of mitochondrial cells. The relevance of that mechanism is illustrated in the panel to the right, which I will simplify by saying that mitochondria generate ATP, which are essential for producing energy for cells, and that is done through the OXPHOS pathway. Blocking the OXPHOS with ME-344 would lead to a decrease in ATP, source of energy, and eventually by a cascade of event to potentially cell death. Separately, purine biosynthesis is done, as I said, at the surface of mitochondria, which ME-344 can block. Purine are essential to cell proliferation, and blocking purine biosynthesis could lead to a decrease in cell growth and proliferation. This is a simple panel of over 200 cell lines that were tested for ME-344 activity in vitro. And as one can see, ME-344 is potent at the nanomolecular level in nearly all cell line tested except a few. MEI conducted two Phase 1 studies, one as a single agent dose escalation to determine the safety efficacy and PK. And that study led to the determination that recommended Phase 2 dose for further development is 10 milligram per kilogram. The next study evaluating ME-344 with a chemotherapy topotecan in a couple of types of solid tumors. 48 patients enrolled in the study. Myelosuppression due to topotecan was observed. We had disease stabilization at 49% of the patients. However, MEI decided to pursue the development of ME-344 in a different direction on the basis of biology. However, before I go to that, this is a table summarizing the safety profile of ME-344 as a single agent in the Phase 1 study, pointing to the fact that neuropathy was seen only at doses higher than 10 milligrams per MYC kilogram was the dose limiting toxicity. It was not reported at lower doses. Now, let's describe the new strategy that we would like to employ ME-344 in combination with the anti-angiogenic agents, primarily Avastin or bevacizumab. This stands for a simple observation that when Avastin is administered to a patient, it blocks the glycolytic energy pathway, leading to effect on cell growth. However, cells are [Technical Difficulty] the ATP I mentioned earlier. Therefore, it is plausible that combining ME-344 [Technical Difficulty] So I'll continue then. Combining ME-344 to block the mitochondrial energy and a VEGF inhibitor like Avastin would now have a possibility of synthetic lethality and therefore improving anti-tumor control. This hypothesis was tested initially in animal model of which I present two, one, a colorectal cancer model and, one, a breast cancer model using ME-344 in combination with oral VEGF inhibitor, nintedanib and regorafenib. And seen on this slide is a decrease in tumor growth for the combination compared to either agent alone and improved survival in colorectal model. This led to a study by collaborate at the NCI Spain in Madrid, a multi-center study, a proof-of-concept study evaluating ME-344 and Bevacizumab in patients with breast cancer. The reason breast cancer was selected is because that is a window of opportunity for this type of mechanistic studies where patients between diagnosis and definite surgery has a period of time where the study could be conducted. It was a randomized control study in 41 patients. Group A received a bevacizumab with ME-344, just one cycle. And Group B received bevacizumab alone. The readout was a PET scan to look at tumor vascularization and tumor biopsy looking primarily at the biomarker of tumor proliferation called Ki67. Results are illustrated on this slide. Group A again is the combination of ME-344, a bevacizumab in green. As you can see, looking at all patients enrolled in the study, there was a significant decrease of Ki67 compared to what observed with bevacizumab alone. Focusing now on the subset of patients in this study who had a tumor normalization vascular -- vascularization normalization by PET, this effect is further enhanced. This led us to the decision now to proceed in a clinical trial with clinical readout, and we selected colorectal cancer as the first study to evaluate the combination because it's an unmet need and Avastin is used in that study. So this is a Phase 1/2 to study in patient relapse colorectal cancer after failure of all standard therapy. Primary objective is progression free survival. Secondary objective are survival and safety. The study is conducted in separate cohort, beginning with cohort one, and using the same dose and schedule that was used in the breast cancer study. 20 patient will be enrolled, and the readout will be that four months after the patients -- last patient is enrolled and considering the positive outcome is a PFS at four months of 20% or higher. Then that will lead to a evaluation of a second cohort and subsequent to a cohort to be discussed with the FDA. With that, I conclude the clinical update and will turn it to Jay File to talk about the financial overview.