Richard Bryce
Analyst · Guggenheim Securities
Thank you, Avanish, and good afternoon, everyone. Following on from our last earnings call in March 2022, we have successfully activated a multitude of sites around the world for our Phase III MANTRA study in dedifferentiated liposarcoma, which I will abbreviate later to DDLPS. These include sites in the U.S., Europe and in Asia. Our site plan built in a degree of redundancy as it was difficult to have predicted how the pandemic was to evolve when we first started planning for the study in early 2021. We also believe that our global site plan was able to mitigate the potential enrollment impact at the Russia-Ukraine conflict. We’re thrilled to announce that we are now over halfway enrolled in the 160-patient study. And as Avanish pointed out, we anticipate enrollment completion by the end of this year with top line data from the pivotal study in the first half of 2023, which is earlier than previously guided. As a reminder, this pivotal trial compares milademetan monotherapy at our preferred dose of 260 milligrams dose daily for 3 consecutive days followed by 11 days off. We refer to this as the 3-out-of-14-day schedule to the approved agent on Yondelis or trabectedin. Yondelis has a published median progression-free survival in the DDLPS population of 2.2 months. In the prior 107-patient clinical trial at milademetan in which 53 patients with DDLPS were enrolled using various doses and schedules, the data previously presented demonstrated that those with the lowest median PFS rates were in the 30 patients receiving milademetan daily for either 21 or 28 days of a 28-day cycle. These dose schedules exhibited a median PFS rate of 6.3 months, which is almost triple out of trabectedin from the DDLPS population in the Yondelis registrational study. In the 16 patients receiving the intermittent schedule of 3 out of 14 days, at the 260-milligram dose, the median PFS rate was 7.4 months. And of note, our Phase III trial is powered to show a doubling of PFS benefit versus Yondelis. And as I mentioned earlier, we anticipate top line data readout from this study in the first half of 2023. Our MANTRA-2 basket trial in patients with p53 wild-type tumors, with MDM2 amplification at copy #12 or greater, is progressing as planned. 11 sites have been activated in the U.S. at the end of April, and additional just-in-time sites will be opened as necessary from referrals from the Tempus and Caris genomic testing services. We anticipate enrolling 65 patients across a range of solid tumors and using the same treatment protocol as in the registrational MANTRA trial. That is with milademetan dosed at 260 milligrams in the 3-out-of-14-day schedule. We anticipate an early data readout in the fourth quarter of this year and reporting patient responses, duration of response and safety in approximately 10 evaluable patients. Based on the progress made with our milademetan clinical program thus far, we’re looking forward to commencing 2 additional studies in the fourth quarter of this year. As Avanish mentioned, we anticipate starting the MANTRA-3 study of milademetan in patients with Merkel cell carcinoma who are resistant or refractory to checkpoint inhibitor therapy. As a reminder, we believe the majority of patients with Merkel cell carcinoma, up to 80% of them have a cancer induced by the polyomavirus, which induces MDM2 overexpression. We are also encouraged by data from other MDM2 inhibitor programs revealing monotherapy activity in this tumor setting. And hence believe that there is an opportunity for an MDM2 inhibitor program that may be better able to manage the on-target cytopenic toxicities. And finally, we’re excitedly anticipating the initiation of our fourth study before year-end to evaluate our first combination regimen with milademetan. This study, the MANTRA-4 study will evaluate the combination of milademetan and Roche’s Tecentriq or atezolizumab, in a Phase I/II study, in approximately 30 patients with wild-type p53 advanced solid tumors that also exhibit loss of the CDKN2A gene. As a reminder, we believe loss of the gene CDKN2A and loss of its protein product, p14ARF, leads to increased MDM2 levels. p14ARF is a natural regulator of MDM2. There are a significant number of patients with wild-type p53 solid tumors with advanced disease that exhibit loss of CDKN2A. This is estimated at over 35,000 patients per year in the U.S., as many as 6% to 7% or more of all solid tumors and is the second most common tumor suppressor aberration after p53 mutation. The MANTRA study will be primarily focused on confirming the safety of the combination regimen but will also evaluate efficacy. With multiple clinical strategies for milademetan underway, we are excited for all the potential new data. So let me turn now over to our Chief Scientific Officer, Bob Doebele. Bob?