Richard Bryce
Analyst · Piper Sandler. Your line is now open
06:37 Thank you, Avanish, and good afternoon, everyone. Following on from our last earnings call in November 2021 where we announced we are progressing with site activations throughout the U.S. and rest of the world for our pivotal Phase 3 MANTRA study of milademetan compared to trabectedin in dedifferentiated liposarcoma, I can report that we were ahead of expectations for site activations at the end of the year 2021, and we anticipate having all sites activated before the end of this month. Patient enrollment continues as expected. 07:10 As a reminder, this pivotal trial will compare milademetan monotherapy at our preferred dose of 260 milligrams and 3 out of 14 day schedule to the approved agent, Yondelis or trabectedin, which has a published median progression-free survival in the dedifferentiated liposarcoma patient population of 2.2 months. In the prior 107-patient clinical trial at milademetan in which 53 patients with dedifferentiated liposarcoma were enrolled, the lowest median PFS observed was 6.3 months. At our preferred dosing schedule, a median PFS of 7.4 months was observed, representing a greater than threefold improvement versus trabectedin. Our Phase 3 trial is proud to show a doubling of benefit. 08:03 We anticipate final data in 2023, but we'll refine that guidance as we move through enrollment. I’m pleased to announce that the first patient was dosed in our second trial, the MANTRA-2 basket trial in November. The MANTRA-2 study is currently planned to run only in the United States, and all primary sites are expected to be activated by the end of this month with additional just-in-time sites being opened if necessary from referrals from the Tempus and Caris genomic testing services. This trial is open to patients with tumors that have p53 wildtype and have a specific threshold of MDM2 amplification. 08:45 As previously reported, we have defined MDM2 amplification for the purposes of the clinical trial as a minimum gene copy number of 12. And as discussed in the third quarter call, this threshold is chosen because the high gene amplification at these levels has been shown to essentially exclude concomitant p53 mutations, thereby ensuring MDM2 as the oncogenic driver in these tumors. We anticipate enrolling 65 patients across a range of solid tumors, and the treatment protocol is the same as in the registrational MANTRA trial, that is, with milademetan dosed 260 milligrams orally, once daily for 3 consecutive days out of 14. We anticipate an interim analysis and early data readout in the second half of this year. 09:38 Also as announced in November, we plan to evaluate the efficacy of milademetan as a monotherapy for the treatment of patients with Merkel cell carcinoma in the second-line setting, i.e., for patients who are refractory or resistant to immune checkpoint inhibitor, which we call the MANTRA-3 trial. We note MDM2 inhibition appears to have gain validation in the Merkel cell carcinoma based on other programs, whereas we believe the improved tolerability of milademetan may offer improved responses and durability. In the second-line setting, post checkpoint inhibitors, the commonly used chemo doublet of carboplatin and etoposide exhibits very short durability of response and no survival benefits has been published from treatments in this setting. We anticipate commencing the MANTRA-3 trial in the second half of this year, and we believe this indication has a high probability of a favorable outcome. 10:40 At the beginning of January, we announced plans to conduct a Phase 1 clinical trial, MANTRA-4, to evaluate the safety, tolerability, and efficacy of milademetan in combination with Roche's atezolizumab in patients with advanced solid tumors with loss of CDKN2A gene function and wildtype p53. Bob will talk more about the mechanism shortly. This will be a dose-deescalation study design, where we will start at the full doses of both milademetan, again, the 260 milligrams in 3 out of 14 day schedule, and the approved dose of atezolizumab or Tecentriq on the Q4 week schedule. We will reduce the dose of milademetan if we observe a dose-limiting toxicity. 11:30 However, as we would not anticipate any overlapping toxicity between milademetan and atezolizumab, this trial could effectively become a 30-patient efficacy signal-finding basket trial across a range of solid tumor types. We're anticipating starting MANTRA-4 in the second half of this year. Upon a favorable safety signal, subsequent Phase 2 clinical trials may evaluate combination of milademetan and atezolizumab in various additional tumor types. To conclude, we have outlined 4 clinical trials of milademetan, led by the flagship MANTRA pivotal Phase 3 trial in liposarcoma. 12:13 The MANTRA-2 and MANTRA-4 trials reflect unique basket study approaches and with MANTRA-3 and Merkel cell carcinoma representing an important unmet medical need. We look forward to presenting some data later this year from the MANTRA-2 basket study, and the MANTRA-3 and MANTRA-4 trials will start in the second half of this year. 12:37 Let me now turn it over to our chief scientific officer, Dr. Bob Doebele. Bob?