HU to Peg Transition Problems -

[LongETinUS]

Hello

I am asking for help with difficulties I am having transitioning from hydroxyurea to Pegasys.

I am 58, male, CalR-ET, diagnosed in 2008, started HU in 2011. After about 9 years stable on HU (0.75 g/day), with platelets in the range 850-1050 and generally feeling OK, I developed resistance to HU. A BMB in 2021 indicated I still had ET but now with grade 1 fibrosis.

For the last year I have been trying to transition Pegasys. I started at 2g HU/day and 45 mcg/week Peg and am now at 1g HU/day and 81 mcg/week. I've been at 1g HU day for about 6 months, during which time I have made small increases in Peg. This temporarily brings my platelets down to under 1000 but after a month or 2 they go up again into the 12-1300s.

The transition has been slow because my WBCs are also suppressed and my Dr (not a MPN specialist) is concerned about me becoming too immune compromised. My hemoglobin levels have also gone down and are now at 11.2 g/dL (They averaged 14.8 for the years prior to any medications). The 1g HU/day had only a small impact on WBCs and hemoglobin when that was all I was taking.

I would be very grateful if any of you could share any experiences you have on how to mitigate the low WBC and hemoglobin levels while on Peg.

At this stage it seems likely to me that the transition to Peg may not work. The medical literature says that in such cases prognosis is not good but I have not been able to find any consensus on what is the best medication choice if HU and Peg have failed. All I found was that Teferri at the Mayo clinic suggests busulfan. Can any of you share your experience/knowledge about this?

Thanks

[hunter5582]

Sorry to hear about the struggles. Unfortunately, most cytoreductive medications affect all blood cell lines. PEG and HU both have this impact. There is another medication option that more specifically targets platelets - anagrelide. There is also a medication in clinical trials that could be an option - bomedemstat.

It sounds like you have a treatment resistant case of ET. You are refractory to both HU and PEG. You indicate that your hematologist is not a MPN Specialist. Suggest that it is time to seek consultation with a doctor who is a MPN Specialist. It is worth doing whatever it takes to make this happen. Many people have to travel to see a MPN Specialist, myself included. It is worth it. Here are the two lists of MPN Specialists to consult.

mpnforum.com/list-hem./

pvreporter.com/mpn-speciali...

Wishing you success is accessing the expertise you need to find a viable way to trat your MPN.

[srtdc in reply to hunter5582]

Hunter...I just wanted to express my thanks, admiration and gratitude for all the help and valuable information you provide. You are truly are a very special person...

G-d definitely takes notice...

[LongETinUS in reply to hunter5582]

Hunter

Thanks for the reply and your many other posts. Yes, a specialist is what I need and will go for.

My hope is that I can keep going long enough to get on the new medication Bomedemstat that appears from phase 2 trials to be very effective. I couldn't find on clinicaltrials.gov where the phase 3 trials will be held. I would move anywhere to get on that.

[hunter5582 in reply to LongETinUS]

There is action happening. Merck had been in the process of acquiring Imago Biosciences. It should be nearing completion. Based on the information out there, I would think that Phase 3 trials should , hopefully, be happening soon.

linkedin.com/company/imago-...

adisinsight.springer.com/tr...

I had the pleasure to meet some of the folks from Imago Biosciences at one of the MPN conferences. Their presentation was very interesting. The promise of another therapeutic approach through LSD1 inhibition, gives hope to people with ET who have not responded to other avenues of treatment.

All the best to you moving forward.

[gset]

Sorry to hear about your problems with Inteferon. I too have Et CALR gene and after 10 years couldn’t use HU any more. Unfortunately inteferon didn’t work for me, it didn’t bring my platelets down and they remained high around 900. I was 53 at the time and worried about my options. I think I too had the same fibrosis as you. I have now been 6 years on anagrelide which has controlled my platelets well and I wish I had been on it earlier as I have less side effects than when I was on HU or Inteferon. It is worthwhile talking to your specialist about your options. I had thought I was out of options at the time but so far so good.

[LongETinUS in reply to gset]

Thanks for the feedback. It is as a very positive example and gives room for hope.

For me a platelet count of 900 is reassuring, I have lived with that or above for 14+ years. It's been up in the 2000s.

Has your Dr checked with a BMB to see if the fibrosis is progressing or do you just get regular blood tests to make sure that aspect is OK?

[Orangeboykitty]

I also took anagrelide when I had to lower my platelets quickly to prepare for surgery. It worked very well. I stayed on it for about a year.

[ainslie]

it may be you need more Peg for longer but what I strongly recommend is you see a MPN. Expert as soon as possible to advise you, Anagrelide exists but I hear from ET veterans that there can be issues with it, I don’t hear of experts talking positively about it. Bisulphan is not used that much but if all else fails some experts use it. Rux maybe a option but you really need to be advised by a MPN expert.

[LongETinUS in reply to ainslie]

Thanks for the help.

Anagrelide is one option, even in combo with the peg, but I saw that in some cases it leads to increased fibrosis. If only we could know ahead of time who those patients would be.

I think Teferi at Mayo goes for busulfan over anagrelide die to the fibrosis issue, and because he says in many of the early studies where buslfan was used the patients were also exposed to other agents making it hard to conclude for sure that busulfan was responsible for negative patient outcomes.

I need a specialist to advise on this.

[Wyebird]

oh dear your reaction to peg is the complete opposite to mine. For a week I took 16 hu and 90 of peg.

Week 2 peg only because my platelets dropped tremendously.

Then it fluctuated because of my WBC. Now over 18 months later I’m on 90 of peg every 17 days ( this is a trial). My haemoglobin has risen from the lowest of 93 to presently 116.

I do hope results improve for the better soon.

I’m CALR ET

Maybe a specialist is required

[gset]

I have had regular bloods and BMB

[George1976]

Agree you need to see an experienced MPN doc ASAP.

I’ve got CALR ET too. Except for a slight hint of sinus pressure in my forehead I felt fine almost 9 years ago even though platets were at 1.7m. We’re all different but one thing I was told by the first MPN specialist I saw years ago that has stuck with me is to stay off the meds (or take just enough) to keep your MPN from causing you a problem. Hopefully a new doc with experience treating MPNs will be able to figure out what you need.

Over the years I’ve tried anagrelide, peg, HU and now Jakafi but I’ve only been on it for a week and a half. Among other things it supposedly has an anti inflammatory effect that could be beneficial even though I don’t have the jak mutation.

Best of luck to you going forward.

[Scottishterrier]

Hi I have been on hu for many years and I am glad to say it was the best decision ever I have had et jak2+ since 1994 I was put on it because I suffered a infarction to the liver I was offered interferon but thankfully I had read in the newspaper a couple of weeks earlier about this person who was on it and the side effects were horrible and my consultant offered me that or hu when I heard it was a chemo drug first thing asked would I lose my hair and he said no but I would not be able to have children but obviously I thought my health is more important I went on it I did feel nauseous but I was now having to see a gastroenterologist because of clot to the liver I count myself lucky as the liver regenerate itself so no real problems I mentioned the sickness and it was trial and error drug wise was put on domperidone 10mg twice a day and my platelets are well under control I would say come summer you have to wear factor 50 and t shirt and a baseball cap as Hu makes you photosensitive my arms swelled up like balloons the first summer in the sun but please go for it it can make you feel tired but recommended it highlyStay safe and good luck

Scottish terrier x