Jorge Cortes
Analyst · Citi. Please proceed with your question
Thank you very much. And my name is Jorge Cortes. As mentioned, I am currently the Director of the Georgia Cancer Center and formerly MD Anderson in the Department of Leukemia, where as the Deputy Chair, and I was there for 23 years on faculty plus my training before that. So I'll be very glad to discuss with you this drug olutasidenib and the role of in patients with IDH1 mutated acute myeloid leukemia. So I'll start with the background on Slide 14. As a reminder, IDH1 mutations occur in somewhere around 8% to 12% of patients with acute myeloid leukemia, you can see depending on different sources and different patient populations, the range may expand a little bit more from somewhere to 6% to 16%. And that's about where we see this type of mutation. As already mentioned, olutasidenib is very important and very select inhibitor of IDH1 mutated. And I will remind you how IDH1 mutations work in acute myeloid leukemia, it's very important because this is one of those mutations that are considered initiating mutations. There are some mutations that happen a little bit later after a leukemia has been developed and some that are initiating mutations, and we think that IDH1 mutations are one of those. That's important because that goes to the root of the development of acute myeloid leukemia. Normally, as you all may remember, from the - from biochemistry, we have this Krebs cycle, which is the metabolism of the normal cells. And it goes to alpha-ketoglutarate and when IDH, which normally metabolizes alpha-ketoglutarate, when it is mutated, it transforms alpha-ketoglutarate into two hydroxyglutarate l or 2HG and when that metabolite 2HG is usually not present in normal cells, in the normal cycle. When it is formed, it has the potential to transform cells into leukemia cells, hematopoietic cells into leukemia cells through epigenetic mechanisms. So actually 2HG becomes a marker, a biomarker of the mutation, IT will go up when there is a mutation of IDH1. And if you inhibit ADH1, the levels of 2HG will go down, which is a good thing because, again, that is what drives the development of the leukemia. So having olutasidenib, a very important, very active drug selective for IDH1 being available, it can reverse that malignant phenotype. So with the understanding of the potential of this drug on slide 15, you can see that we have from the very beginning, when I started being - I started getting involved with this drug from the very early stages of the development. And we very quickly developed a very comprehensive plan for the development of olutasidenib, both as a single agent, as a monotherapy and in combination with other agents, knowing that sometimes in leukemia you need a combination for certain settings. So the monotherapy includes refractory, relapse and other settings, including some exploration of the treatment-naive patients, patients who have not received prior therapy, those are the orange boxes. And we explore that also in the combination therapy. Now for the purposes of this presentation, the data that is most mature is what you'll see in Slide 16, the refractory relapse patients, monotherapy which is the primary indication that's going to be pursued again, because that is where most of the data is at the moment, that's where we usually would start the development of a drug. So for this cohort, the primary endpoint was the achievement of what is called a CR or a CRH, I'll get to the definitions of that in a couple of minutes. And there is essentially the responses, but we have important secondary end points, the overall response rate, the duration of the remission, the transfusion independence, the overall survival and, of course, the safety of the drug. So let me describe the results. And on Slide 17, you can see the patient characteristics of those that are included in these evaluable cohort that's being presented now. These are mostly older patients. The median age is 71. We do have some younger patients, but you can see at the upper end of the spectrum, we had patients way up into their 80s, included in this study. Two thirds of the patients are what we call the novel AML, meaning this is a disease that happens for the first time, as opposed to the secondary AML, which is about a third of the patients, that is an AML that evolves from other malignancies, a myelodysplastic syndrome most frequently, but it could be from other hematologic neoplasia, sort as myeloproliferative neoplasms and others and a few that had treatment-related AML in patients that had other cancers, breast cancer, lymphoma, et cetera, you give them chemotherapy, they developed the AML. Those were just a few. It's most typical that this mutation happens in patients that have either no chromosomal abnormalities or very frequently extra chromosome 8. Those are what we call intermediate risk chromosomal abnormalities, and it represents the majority of these patient populations. But there's a good - a little over 20% that have a poor risk chromosomal abnormality. By definition, all the patients had an IDH1 mutation, the different variations of the IDH1 mutation. The most common is R132C, that's a little over half of the patients and then some of the others that you see on this slide. We also know that patients with acute myeloid leukemia do not always only have one mutation, the mutations in other genes could coexist with IDH1 mutations. The most frequent that we saw in these cohorts was NPM1 that occurred in almost 30% of the patients, but we saw mutations in other genes B3 and others, as you can see on this slide. We're talking about refractory or relapsed patient population. Refractory means, you gave them initial therapy. They did not respond at all. That is the largest cohort, and it's a little over 40% of the patients. The others are relapsed. That means you give them some initial therapy, they responded, but the disease is coming back. The worst-case scenario is that either the disease comes back quickly before 12 months. That is the highest risk, the patients that tend to have the worst prognosis. And that is the next largest cohort, 37%. There also could be patients that have had a response and relapse, you give them something else, responded again, they relapsed again. So two or more relapses that’s also pretty, bad 20% of the patients in this cohort are like that. And the best case scenario is the patients who have a first relapse and the first remission lasted more than 12 months. That’s a smaller subset of these patients, only 11% of the patients. You can see actually, that most of the patients had received, the median number of prior regimens was two. So they had received at least two prior therapies before they came to the studies, some had received as many as seven, and 11% had received actually a stem cell transplant. All right, let's jump to the response rate then. This is on Slide 18. And you can see here that I mentioned the primary endpoint was CR plus CRH. Let me define that for those of you who may not be as familiar. CR means that the blast counters [ph], the blast or essentially the leukemia cells, the normal is less than 5%, more than that would be the leukemia. So CR means that the blast count has gone down below 5%, and the platelets have recovered to at least 100,000 and the neutrophils to at least 1,000. That's a CR. If there is some recovery of the neutrophils and the platelets, but not completely, so the neutrophils are more than 500, but not quite more than 1,000. And the platelet is more than 50,000, but not quite more than 100,000. With the blast still less than 5%, that's a CRH. So you can see here that 33% of the patients achieved that primary endpoint. Importantly, the great majority of these are the full CR, 30%. So only four of the 41 patients who responded are CRh. CRh is - are good, but certainly CR is the ultimate response. We also have some patients that have some recovery of the neutrophils and the platelets, but they do not quite make it to that - to those ratios, the 500 and the 50 of the CRh. We call those CRIs. There's an additional 11% of patients who have this response. And then a couple of smaller categories, MLFS, means morphologic leukemia freestate, the blast count went down to less than 5%, but there's not really much recovery in the platelets or the neutrophils. And the PR means the blast count went down, but it did not go all the way down to less than 5%. Let's say, somebody started with 90% blast, and it went down to 8%. While that's a partial response, doesn't quite make it to the full criteria of less than 5%. If you take all of these together, almost half of the patients responded, 46% of the patients had at least one of these categories of response. But very importantly, what you see on Slide 19 is the duration of response. You want to see that these responses last for some time, not just happen one time and then immediately the patient relapses. As you can see here, the duration of response is the median duration is - has not yet been reached. At the time of this analysis, if you do a very conservative approach, what's called the sensitivity analysis and say, well, because some of these patients went to a transplant. I'm going to end the response at the time they went to a transplant. So I don't adjudicate to the drug something that was partially attributed to the transplant, then the median duration is 13.8, still a very, very good outcome. And again, it's not that they relapsed at that point. We just stopped counting because they went to a transplant. And then on Slide 20, also something very important. I mentioned that the primary endpoint was CR and CRh and this shows the survival of the patients according to the response that they had. The patients who had a CR or a CRh, the median survival has not yet been reached, by 18 months, the 87% of patients are still alive, which is an outstanding outcome. Now very importantly, some of these lesser responses that I mentioned, the CRIs, the morphologic leukemia-3, they also have a survival benefit. These patients had a median survival of 15 months or more than a year compared to the patients who did not respond, who have a median survival of only four months. So that means that even the lesser responses have value to the patients, add to the survival probability significantly from four months to 15 months as the median. Let's talk now a little bit about the safety of olutasidenib. I am showing you here what is called treatment emergent adverse events, TEAE and what that means is any toxicity that happens while the patient is - anything that happens while the patient is taking the drug, we are not making assumptions that it was related or not related. We just say it happened, we report it. So anything that happened in 20% of patients or more or that was a Grade 3 or 4 in at least 10%, Grade 3 or 4, the more severe instances of these adverse events. When you treat patients with leukemia, it's very typical with any treatment that their neutrophils go down, the platelets go down, the hemoglobin goes down. So that is a fairly standard with chemotherapy 100% of patients have these things. Well, that's the great majority of the adverse events that you see here reported on this slide. It's anemia, it's the thrombocytopenia, it's neutropenia. And actually, those are the only ones that reached any significance in terms of Grade 3 or Grade 4. And of course, the patients who drop their neutrophils very frequently have fever as well. But other than those, the only ones that stand out of any grade are some nausea in a little over a third of patients, constipation in a - quarter [ph] of the patients, some fatigue in 20% of the patients. But none of these really make it to any Grade 3 or 4. So these were mild side effects that clearly manageable for these patients, maybe much better than what you would expect with a chemotherapy, for example. Now moving to Slide 22. I want to point some of the adverse events of special interest on some things that are of particularly important. First, QTc prolongation. With QTc, the QT is an interval in the electrocardiogram, you've seen those graphics of an electrocardiogram. You measure from one wave that's called the Q wave and the other wave that's called the T wave. You see the interval between those. If it gets very long, there is risk of very [indiscernible] that can be even fatal and we see that sometimes. Now fortunately here, it happened very infrequently, less than 10% of patients had any QTc prolongation. But most importantly, the ones that we worry the most about, the Grade 3 and the Grade 4, the very long intervals, it happened in only one patient and was Grade 3. But even that did not lead to discontinuation of the drug. So it was a very low rate and very manageable. Then we have liver abnormality. This were perhaps the adverse events other than the blood counts that we saw more frequently. You see any grade happened in anywhere between 27% for bilirubin to 42% with one of the transaminases AST. Fortunately, these were Grade 3 in a small percentage of patients. So overall, 20% of patients had any elevation of liver enzymes, but only 12% have Grade 3 or Grade 4, most of these are actually Grade 3. But very importantly, of these 32 patients, 25 of those 32 did not require any dose modification or if they had a dose modification that was enough for the patient to continue on therapy. There were only seven patients with discontinued treatment. For with recurrence, three others investigator did not want to re-challenge with dose adjustments or anything. So we don't know what would have happened there. And then differentiation of syndrome is something that we've learned happens with IDH inhibitors, is part of a process of maturation, but it can come with symptoms with problems that happen. But fortunately, it happened only 14% of these patients and the most - and about half of these were Grade 1 or Grade 2, the others were Grade 3 or Grade 4, 8% total, only three patients, however, discontinued treatment because of the differentiation of syndrome, meaning the great majority of these are very - they can be managed well with treatment interruptions. We know some drugs that use corticosteroids on mild chemotherapy like hydroxyurea a. So a very, very manageable toxicity because of the low rate and the low intensity of these events. So my conclusion is that with this interim analysis, we see that olutasidenib has a very high response rate, very high rates of CR/CRh, but very importantly, most of these are true CRs, and they're durable remissions that even with a very conservative analysis accounting for transplant the median duration is more than a year in this very heavily pretreated patient population. And that these benefit extends even patients that do not have the full CR or CRh with all the responses, they also have a survival benefit. And this comes with a drug that's oral, that's very well tolerated, that most of these toxicities are very manageable, very mild and that makes it a very applicable, very welcome drug for the management of these patients with IDH1 mutation, with acute myeloid leukemia. So this is my presentation. I thank you for your attention, and I'll hand it over to our next speaker.