Richard Bryce
Analyst · - I'm sorry, our first question is from Michael Schmidt from Guggenheim Securities. Please go ahead. And now, this is Graig Suvannavejh from Goldman Sachs. Please go ahead
Thank you, Avanish and good afternoon, everyone. So one of the key differentiators of milademetan is a late clinical-stage MDM2 inhibitor, as it's potentially favorable safety profile over that reported from others in this class. And in particular, we want to remind everyone of the low levels of severe cytopenias that is to say the hematological toxicities that were observed with milademetan from the larger prior study completed last year. Specifically, the rates of grade 3 and 4 thrombocytopenia, neutropenia and anemia were 15%, 5% and 0%, respectively in the preferred dosing schedule. In that study, milademetan was investigated in 4 different doses and schedules, with the optimal dose and schedule determined to be 260 milligrams given by mouth daily for three days, followed by a 11 days off on a repeating schedule. In other words, patients receiving the milademetan 6 days out of a nominal 28-day cycle. Our pivotal trial, the MANTRA trial mentioned by Avanish, is in the second-line setting, in de-differentiated liposarcoma, DD LPS. The current standard of care in liposarcoma today, after anthracycline-based chemotherapy is another type of chemotherapeutic agent called trabectedin, trade name Yondelis, which demonstrated the median progression-free survival or PFS of 2.2 months in DD LPS. In the previous milademetan study, there were a total of 53 patients with DD LPS enrolled. Now, we want to point out that some of our enthusiasm for milademetan stems from the prior data, in which, the cohort of patients treated with the dose and schedule with the worst PFS, still had a PFS of 6.3 months. That's still tripled that of trabectedin. And the cohort of patients that received 260 milligrams of milademetan in their preferred dosing schedule of 3 days on and a 11 days off, which demonstrated the most favorable tolerability, exhibited a median PFS of 7.4 months. Improved safety and better tolerability appear to actually lead to numerically-improved PFS, compared to those described in the literature and the syndication. Further, and it has been published earlier. Patients in that prior study exhibited some very long durations of treatment, extending and ongoing over several years in some instances. We believe the safety profile exhibited by milademetan from the prior study with the results of identifying an appropriate dosing schedule. The entirety of the MDM2 competitive landscape has been focused on trying to identify the right dose and schedule for a specific compounds of properties. Based on this prior trial, we believe milademetan is the first program with clinical evidence of a potentially successful efficacy and tolerability combination that is based on identifying the right dose and schedule. As Avanish mentioned, we recently announced the start of our pivotal Phase 3 MANTRA study for milademetan in patients with DD LPS. Last month, we announced the first patient randomized into the trial. This Phase 3 study of milademetan versus trabectedin is being conducted in patients with unresectable or metastatic, de-differentiated liposarcoma with or without a well-differentiated component, who have progressed on one or more prior systemic therapies, including at least one anthracycline-based therapy. This global study will randomize approximately 160 patients on a 1:1 basis to either milademetan at a dose of 260 milligrams orally, on days 1 to 3 and 15 to 17 of each 28-day cycle or to trabectedin at the standard label dose. The primary objective is to compare progression-free survival, which is an endpoint - an event-driven endpoint. The [technical difficulty] between the milademetan treatment arm and trabectedin control arm as determined by blinded independent central review. Secondary endpoints include overall survival, objective response and disease control rate, duration of response, PFS by investigator assessment and patient reported outcomes. This will be a global study at approximately 70 sites planned across North America, Europe and Asia. We moved quickly to get this trial started, commencing a pivotal registration enabling study after discussions with the regulatory bodies in under three year from in-licensing the program. Our second trial expected to begin enrollment in the second half of this year is the MANTRA-2 study. This Phase 2 study is planned to be multicenter, single arm, open-label basket study, which is designed to evaluate the safety and efficacy of milademetan in patients with advanced or metastatic solid tumors, refractory or intolerant to standard of care therapy that exhibit wild type TP53 and then the MDM2 copy number 12 or greater, using pre-specified biomarker criteria. Our analysis of the mutual exclusivity of TP53 mutations, and the MDM2 copy number is revealed that MDM2 gene amplification beyond copy number 12, largely occurs without concomitant p53 mutations. And we therefore believe that MDM2 may be the oncogenic driver in these cancers. So we plan to enroll approximately 65 patients into this trial, and would anticipate that the frequency of tumors would be greatest among breast, lung and bladder cancers, amongst - various others to be studied. We've also entered into agreements with Tempus for comprehensive genomic profiling tests, utilizing their genomic analysis platform, as well as the patient referral partnership with Caris Life Sciences relative to our MANTRA-2 study to help identify patients potentially eligible for the study. And finally, we plan to commence the Phase 2 study of milademetan in patients with advanced or metastatic intimal sarcoma by early 2022. Intimal sarcoma represents a very small patient population, ultra orphan, and again, is predominantly an MDM2 gene amplified cancer. We believe milademetan may offer a treatment strategy for patients with this disease that currently have no therapeutic options. Let me now turn it over to our Chief Scientific Officer, Dr. Bob Doebele. Bob?