Which Emerging Myelofibrosis Therapies Are Showing Promise?
Which Emerging Myelofibrosis Therapies Are Showing Promise? from Patient Empowerment Network on Vimeo.
What are the latest advances in myelofibrosis therapy? Expert Dr. Gabriela Hobbs discusses various inhibitor therapies, including BET inhibitors, that are currently being studied in clinical trials for patients with myelofibrosis.
Dr. Gabriela Hobbs is a hematology-oncology physician specializing in the care of patients with myeloproliferative neoplasms (MPN), chronic myeloid leukemia and leukemia. Dr. Hobbs serves as clinical director of the adult leukemia service at Massachusetts General Hospital. Learn more about Dr. Gaby Hobbs.
See More from Evolve Myelofibrosis
Related Resources:
Evolving Myelofibrosis Treatment Options: What You Should Know |
|
Myelofibrosis Clinical Trial Participation | How Does It Move Research Forward? |
Transcript:
Katherine:
Can you share with the audience how the field of myelofibrosis has changed over the course of your career?
Dr. Hobbs:
Yeah, so it really has been a very exciting journey. So, when I was in medical school, I think that we basically had just discovered the JAK2 mutation.
So, in the course of my own training and then my professional career, we’ve gone from myeloproliferative diseases being conditions where we really didn’t necessarily have a reason why people would get these conditions. Now not only do we know about the JAK2 mutation, but we know about many other mutations that patients can have. Then in 2011, the first JAK inhibitor was approved, ruxolitinib (Jakafi), and since then, three additional JAK inhibitors have now been approved, including pacritinib (Vonjo), fedratinib (Inrebic), and most recently, momelotinib (Ojjaara).
So, the field has definitely advanced concretely in that regard. But we also just have much more information about how to diagnose these conditions and also how to treat them. Outside of the JAK inhibitors, we’re better at recognizing when patients need to go to get a bone marrow transplant. For example, and our outcomes with bone marrow transplantation have improved significantly. We also have many other treatment approaches that wouldn’t have existed before, and we also recognize that patients with MPNs live with a lot of symptoms. So, I think that we’re better at just the doctoring part of taking care of patients with MPN. So, definitely, the field has just really, really changed significantly in the last two decades.
Katherine:
What are new and emerging therapies that are showing promise?
Dr. Hobbs:
Yeah, so the list is long and it’s getting longer. So, in addition to the fact that we now have four JAK inhibitors approved, which is worth just remembering that, because not that long ago we only had one, and one of them was just approved less than six months ago.
There are many new agents that are being studied in combination with the JAK inhibitors. This past year at the American Society of Hematology meeting, which is the annual meeting where we go to share our research and learn from our colleagues, there were two Phase III studies that were presented at the same time.
I can’t remember, or I don’t think, but that has really ever happened before for myelofibrosis. One of them was with an agent called pelabresib, which is a type of molecule called a BET Inhibitor. And the other one was with an agent called navitoclax, which is an agent called a BCLXL-BCL2 inhibitor, which is a molecule that helps cells to undergo apoptosis or programmed cell death.
So, these molecules were both combined with ruxolitinib. And we saw the results of the Phase III studies for each of these agents, and they were really quite exciting. The punchline for both of these studies is that they demonstrated that when you give two drugs as opposed to just one, the amount of patients that have a significant reduction in their spleen is doubled than when you give ruxolitinib in it by itself. So, for some of our patients that is a really meaningful number. You know, if you’re a patient that suffers from a big spleen, knowing that there’s a possibility of having two drugs that you can take to really shrink that spleen in a significant way, I think is very, very promising. On the symptom front, taking two medicines versus one medicine really didn’t seem to make a huge difference. I think we can analyze this in two different ways.
We can see the negative or the positive side of this. So, on the negative side, well, it’s too bad that, you know, added medication didn’t help patients feel better. But on the upside, it’s also good that taking two medicines didn’t make people feel worse. Sometimes you can think of, you know, if you’re taking more medication, maybe you will feel worse. So, the jury is kind of still add on the significance of those results.
But regardless, without getting into too much detail about these studies, I think it’s really exciting for myelofibrosis patients to know that there are two agents that are in Phase III testing. That means that the next step is really consideration of FDA approval. So, when medications go through clinical trials, they go through earlier phase studies, Phase I, Phase II, and then finally they get to Phase III. A lot of work and effort has gone into these two compounds to try to get them to FDA approval. So, we’ll wait and see if in the next year or so we have new agents for the treatment of MF.
In addition to these two, which of course are the most advanced, there really are a variety of other agents that are being tested. Those, for the most part, are still in Phase II testing. And similarly to the ones I mentioned before, most of the compounds, the way that they go into trials is first they start out showing that they’re safe by themselves, and then they get added to a JAK inhibitor.
So, far, because ruxolitinib has been the one that we’ve had around for the longest, most of these studies are being tested in combination with ruxolitinib. But we start to hear rumblings from clinical trials that perhaps some of the newer trials will consider using other JAK inhibitors as combination partners, which is a natural evolution. So, to name a few other agents, we have drugs like selinexor (Xpovio), and navtemadlin we have a PIM kinase inhibitor, a lysyl oxidase inhibitor, an LSD1 inhibitor, the list is long of all these different agents.
Preliminarily, at least from the data we’ve seen from all of these compounds, I think there’s a lot of room for excitement. We see that combining these drugs together, the new agent plus the ruxolitinib, leads to a significant reduction in the spleen. And in some of these agents, we’re starting to see other endpoints. So, in addition to just looking at can we make patients feel better and can we shrink their spleens?
We’re starting to look at other things such as when we add these medications, do we see a reduction in the scarring or the fibrosis in the bone marrow? Do we see a decrease in the cells that have the mutation? Do we see the patients live longer? All of those things are endpoints in our studies that we really haven’t tested before. So, I think the field really will produce a lot of exciting data in the next couple of years.
Katherine:
You mentioned clinical trials, and we will talk about those in a few moments, but are there innovations in technology that are accelerating myelofibrosis research?
Dr. Hobbs:
So, the most obvious way to answer that question is simply that it’s much easier to diagnose myelofibrosis now, thanks to the ability to do genetic testing now much more easily than before. So, I think that previously, you know, getting JAK2 testing or testing for the other mutations was not as simple or would take a long time for the results to come back.
Now, you know, I see even in the smallest of practices, ordering not just the JAK2 gene, but ordering what many of us do, which is like a panel of genes, where you test for a lot of the genes at the same time, has become almost commonplace. So, that’s really a meaningful advance in that it’s a technology that’s available and it’s no longer as prohibitively expensive as it was before.
That doesn’t mean that some patients don’t end up getting charged in ways that doesn’t make any sense anymore, but that’s a conversation for another time. But I think just having the ability to make those diagnoses because of how easy it is now to test for these mutations is really very meaningful. Outside of that, I mean, I would say that along with the improvement in the knowledge of what mutations patients have with myelofibrosis, we definitely have deeper ways of analyzing what genes are being expressed and in what cells they’re being expressed to really understand, you know, when do patients first get those mutations and how do those mutations change over time.
So, we’re really diving deep into the actual biology of the bone marrow and there’s some studies that have demonstrated that patients may even have the JAK-2 mutation in utero, which is really, really fascinating. So, definitely a lot more understanding of the actual biology of how these diseases happen.
