ET, JAK2, ASXL1 and Besremi

[Mtn_Lake_4ME]

Hello~

First of all, I would like to thank all of you for your shared stories and accompanying research. I have learned many new things and appreciate the links to research! I have been living with ET-JAK2 positive along with ASXL1 for nine years. I was diagnosed at age 58 and started Hydroxyurea within four months due to concerns that I may have experienced a TIA. I have tolerated Hydrea well, but have been presented with the idea of switching to Besremi. I live in the United States and I am fortunate to have an MPN specialist at a highly regarded hospital. In March 2016 my allele burden for JAK2 was 9.1% and ASXL1 at 30.8%. I understand that Besremi can reduce the JAK2 load, but my doctor doesn’t know how it will affect me since I also have ASXL1 mutation which is rare in ET and usually seen more in leukemia. Is there anyone who is similar to me with ET, JAK2 and ASXL1. Wondering if you have ever tried Besremi or if there is any research that addresses that. With ASXL1, if I do progress, it is an aggressive gene with poor clinical outcomes. I do feel as though I am in a dilemma as I should do everything to reduce my risk of progression, but also don’t know how it will affect ASXL1 gene. I appreciate you taking the time to read this and any feedback you can provide.

[lakeview65]

I have ET, when diagnosed at age 65 (three years ago) my Jak2 was 9% and my ASKL1 was 32%. I do question both of my hematologists and my MPN Dr. and no one ever has any answers for me so for now I just live my life and occasionally I do a bit of research which also seems a bit futile.

I would love to hear more about switching from Hydroxyurea(which I have been on for 3 years) to Besremi. Could it help? The unknown is the tough part, ASKL1 has such a bad outlook but not much info for us with ET and ASKL!.

[Mtn_Lake_4ME in reply to lakeview65]

I am fortunate feel good and have responded well to HU. I am in the research phase to see if I should take the risk with Besremi and will share any information that may be helpful. When I've asked about progression, it is so individual that doctors really can't predict. I think having a positive outlook really helps. Hope you continue to feel good as well.

[EPguy]

You're right that IFN can reduce Jak2, but the effect of and on ASXL1 is less clear.

On research, I recalled some work on addressing ASXL1. There's nothing yet in the clinic but you might follow the progress of "EP31670 "

" Pharmacologically disrupting the oncogenic interaction at such enhancers with EP31670 in primary patient samples led to significant therapeutic effects (on ASXL1)"

ash.confex.com/ash/2023/web...

--

Another report with Ruben Mesa as an author:

This preclinical finding provides compelling evidence that (administration of GSK-J4) targeting KDM6B may be a therapeutic strategy for myeloid malignancies with ASXL1 mutations.

scholars.uthscsa.edu/en/pub...

So pre-clinically there is at least EP31670 and GSK-J4 as promising agents. If these go to trials there may be opportunities.

[Mtn_Lake_4ME in reply to EPguy]

Thank you for taking the time to respond and sharing this research. I really appreciate it.

[Silvia11]

why is Besremi please

[Mtn_Lake_4ME in reply to Silvia11]

It is an interferon injection that has been approved for PV and is supposed to reduce allele mutation burden. It is just started to be used for ET.

[WIL2US]

I switched to besremi about 18 months ago because the hydroxyurea and phlabotomy would keep my hematocrit down but my platelets weren't controlled. The besremi seems to take quite a while to get control of my hematocrit but the platelets came down quickly. I haven't had a phlabotomy since Aug and my mutation frequency is down from 59 to 30 percent. I'm very hopeful.

[mfh7]

My situation is different in that I have PV and not ET and everyone responds differently but it might be one data point for you. I am jak positive PV and started besremi at age 55 after five years of phlebotomies took their toll on iron counts. Had a bmb prior to starting besremi. Jak2 was 45% and asxl was 10%. Tolerated besremi well and it greatly reduced my platelets to the normal range. The problem with besremi for me was that even after two years of besremi including a final year at the max dose I never was able to get hct control and was still requiring phlebotomy every other month. Since hct control is a key factor for PV my i discontinued besremi and now I’m on jakafi. After four months on jakafi my labs are all in normal range without phlebotomy so all good so far. Only downside to jakafi is I am hungry all the time which is apparently common. My mpn doesn’t know why jakafi works for me to control my counts when interferon did not but apparently I am in the minority. I will say it was amazing in lowering my platelets.

New bmb after two years of besremi but before jakafi showed jak2 ab went from 45% to 25%. Asxl went from 10% to less than 5%. Not sure what effect jakafi may have on those numbers going forward but MPN says she has seen positive allele burden responses from jakafi just like interferon. Hope this helps and best of luck.

[Mtn_Lake_4ME in reply to mfh7]

Sounds very promising! Happy to hear your allele burden is being reduced. Thanks for sharing!