And that means even though we’re concentrating on AML and STS, Annamycin should be relevant to 10 times as many patients once expanded to additional indications. As it relates to expanding our pipeline, by the way, we are very effectively utilizing non-dilutive institutional funding for clinical development. In addition to our sponsored research at both MD Anderson and UTMB, we’ve benefited from clinical development funding from MD Anderson, Emory University, and the Madame Curie Institute in Poland. And we’re expecting several clinical trials to benefit from outside funding this coming year. And our sponsored research has paid some big dividends thus far. In addition to demonstrating the synergy between Annamycin and Cytarabine that’s now playing out in our Phase II AML trial, this ongoing research also eliminated the fact that Annamycin is 30 times better at accumulating in the lungs than doxorubicin, making it an ideal candidate for advanced STS, which is most commonly what is the point of metastasis is to the lungs.
So with that as background, I’d like to invite our Senior Chief Medical Officer, Paul Waymack, to give you the specifics on the new data.
Paul Waymack: Thanks, Wally. It has taken a long time to get to the point of generating Phase 2 clinical data for AML, but we are finally there. Part of the challenge from a regulatory standpoint was needing to demonstrate the safety and the efficacy of Annamycin as a single agent before combining it with Cytarabine for AML patients. Given that we also had to demonstrate that patients could be safely dosed at well above the FDA’s maximum allowable anthracycline dose, this also meant we had to work with patients who were receiving third, fourth, fifth line, or worse therapies, which are the most difficult patients to treat and expect any impact. Now notwithstanding all these challenges, we are now finally treating AML patients in a Phase 2 study with Annamycin in combination with Cytarabine, a combination our preclinical testing suggested would be even more effective for AML patients.
And this appears to be the case. We now have data from the first eight patients who incidentally entered our trial with a median of four prior therapies. We are very pleased to report that among patients who have completed their Annamycin dosing, we have three complete responses. This represents a 38% response rate, something that would not be expected in such heavily pre-treated patients. For comparison, you may recall that Wally mentioned the approval of Veneza [Ph] was based on a 37% complete response rate. So we are already performing at a level that we believe will support marketing approval of Annamycin. And what’s more, we are doing this in heavily pre-treated patients, whereas the Veneza trial for approval was in first line therapy patients.
When you look at the specifics relating to our complete responders, there are some valuable insights that are now apparent. First, one of them responded to Veneza but then relapsed. One was refractory to Veneza and the other had no prior exposure to Veneza. The first two responders are now confirmed as durable with one at eight months of remission and climbing and the other having just received a bone marrow transplant three months after treatment with Annamycin. We can’t yet declare durability for the third patient simply because not enough time has passed since their treatment and remission. It’s also worth pointing out that all three of these patients were treated well above the lifetime maximum allowable anthracycline dose of 550 milligrams per meter square.
Again, this is what we were hoping to see in AML and if we continue to see this level of activity, we think we’ll be in a very good position to establishing a marketing approval pathway. Turning to our soft tissue sarcoma, we now have complete enrolment of the Phase 2 arm of our U.S. clinical trial and are able to present some preliminary data from the trial as a whole. There’s a lot to process here but in total, we believe this trial’s data bodes well for an ultimate approval in advanced soft tissue sarcoma. The unmet need here is so great that most of the recent approvals have been based on the very modest improvements in progression-free survival or PFS. It took us a while in this trial to zero in on the optimal dosing regimen and it turns out that the most productive dosing regimen is not the highest dose we tested.
When isolate for this optimum dose, which turned out to be around 330 milligrams per meter squared, the column on the far right shows that we had a 78% response rate with 56% of the patients reaching three months or higher progression-free survival among patients who had received one or two prior therapies. That compares favorably with other approvals for the indication, but it’s only half the story. One of the shortfalls of second-line therapies is delivering extended overall survival. Although we haven’t had enough elapsed time in the Phase 2 group to reach the medium overall survival, since 12 of the 17 patients receiving Annamycin are still alive, and the median overall survival won’t be reached until the number still alive falls all the way down to eight, we can look to the Phase 1 cohort’s data where we see overall survival at 11 months and climbing.
Considering that the median number of months from diagnosis for patients entering the Phase 2 portion of our trial was 20, the overall survival that we appear to be headed for could be an even stronger basis for a marketing approval. We had the pleasure of sharing these data with a group of soft tissue sarcoma key opinion leaders at the recent CTOS, that’s Connected Tissue Oncology Society Conference in Dublin, and the enthusiasm was high. As a result, we now have two different groups proposing to run their own versions of a pivotal approval trial, which we expect to be kicking off next year. I’ll now hand it off to our Executive Vice President and Chief Financial Officer, Jon Foster, to wrap up the call. Jon?
Jonathan Foster: Thanks, Paul. We ended the quarter with roughly $25 million in cash on hand, and our balance sheet remained clean with no debt and little overhang with warrants. With our current burn rate, this cash will get us into the third quarter of 2024, a runway that we’ve been consistent in our discussion since our last major equity raise in 2021. We have just short of 30 million shares outstanding. This runway allows us, we believe, to deliver these milestones into 2023, early 2024, and set the table for delivering the milestones later in 2024. Regarding Annamycin for the treatment of AML, with MB-106 being an open-label trial, we will continue our quarterly clinical trial updates and also concurrently with other events, such as scientific conferences or other public presentations.
With us delivering the efficacy discussed, recruitment has picked up, and we expect recruitment to be fulfilled in early 2024, if not sooner, and engaging with the FDA and the EMA with the end of Phase 2 meetings. From that, we expect to identify the next steps for the next pivotal clinical trial and begin that at the earliest in the second half of 2024. Regarding treatment of advanced soft tissue sarcoma, we will continue to monitor subjects for OS and PFS, and we expect to report in the second quarter of 2024 that final readout. That’s not stopping us in moving forward with discussions with investigators for a possible investigator-funded trial, either partly or fully in first-line treatment of advanced STS, just as Paul discussed. The response to our meetings with investigators at CTOS leads us to believe that the next program could be identified in either the U.S. or the EU in the first half of 2024 and initiated in the second half.
All of these milestones are building upon the efficacy data that we just discussed. Wally?
