Prithviraj Bose, MD discusses typical patient outcomes in PV and other myeloproliferative neoplasms, emphasizing the importance of patient priorities and symptom management.
Prithviraj Bose: The outcomes for patients with PV and ET overall are good. So, these are, of course, the indolent ones among the classic myeloproliferative neoplasms. And so when you compare to myelofibrosis, for example, the outcomes are much better. And for that reason, we're not transplanting anybody with ET and PV, for example, because their median survival is fairly long. At least compared to myelofibrosis. So, in ET, we generally think that the median survival is not different from an age and gender matched population. In PV, it's been reported to be between 14 and 19 years. And PV definitely is a worse disease than ET. That's well known. Both of them can, of course, progress to myelofibrosis and rates have been published at 10 years, at 15 years, you definitely have a reasonable chance around 10% in PV, although there are ranges, of course, across different studies of progression to myelofibrosis and smaller risk, thankfully, of transformation to AML. So, generally, these are diseases that people live with for many years. And obviously, because of that, day to day symptoms become an issue. It's not just about controlling the counts and preventing blood clots, which continues to be goal number one. But I think there's a lot of other things that we need to pay attention to. In fact, there have been studies like the MPN landmark study, which have shown that there is some discordance between patients' priorities and physicians' priorities. So, for example, patients are very keen to modify their underlying biology to sort of stop or halt or slow this inexorable disease progression that may otherwise occur. So that is more important to them sometimes than preventing a blood clot. That's not to say that a blood clot couldn't be bad. It could be a stroke or a heart attack, but in patients with these chronic diseases, it's really important to them to try and do something to the root cause, so to speak, and its natural course. So this is where I think the increasing interest in getting this allele burden of JAK2 down, regardless whether that's with an interferon or with ruxolitinib, is gaining ground. And the hope is that that would translate to improved myelofibrosis-free survival, improved overall survival, and increased leukemia-free survival, all of that. Now, symptoms is another whole different and important domain. Symptoms, many studies have shown that MPN patients, PV, ET, MF, all of them, MF usually more symptomatic than PV, but PV more symptomatic than ET, have a wide range of symptoms. And they can be debilitating, disabling sometimes, or at least bad enough that they impair quality of life, work productivity, etc. There's been many surveys of patients that have shown these. And so certainly, this is important to elicit from patients. As I said earlier, using that MPN SAFTSS form is very helpful, because it allows you to objectify it and follow it over time. And we do have drugs, for example, ruxolitinib that comes to mind first, as a drug that addresses symptoms really more effectively than any other drug right now with PV. And so, it certainly draws attention to the fact that we need to be cognizant of symptoms and always elicit those and see how well we're doing with that aspect, beyond the more traditional aspects of treating patients with PV.