Did the Cork forum really say that peg doesn't work for 20% of people?

[Joetcalr]

At 53 mins in there was a chart which was a little blurred but seemed to show that for ET, is anyone with a better screen able to check?

I'm having such problems with anemia, currently 90 (US .9), it's been drifting down ever since I've been on pegasys, I'm so tired of being tired!

Seems the only way forward, as the haem doesn't acknowledge that peg might not work, is another spleen scan and a bm biopsy I've no symptoms for mf which is what the haem is thinking of. Anyone else given up peg because of anemia? Many thanks Jo

[hunter5582]

Most cytoreductive meds reduce production of all blood cell types. Unfortunately, all of the standard cytoreductive meds (except maybe anagrelide) come with a risk of anemia. Pegasys specifically can cause aplastic anemia.

I would wonder if your doc has checked for iron deficiency just to be sure you know what is going on. Might be worth checking if not already done.

SInce I have PV, lowering RBC count is a good thing. It is why I chose Pegasys and later switched to Besremi. I also have thrombocytosis and the IFNs do a great job keeping PLT in check. It is coming at the cost of mild leukocytosis. I have maxed out the Besremi dose because of that.

Hope you find answers and a solution soon.

[monarch5000]

To counter anemia some patients take a HGB booster drug with Pegasys; e.g. Procrit, Danazol, Aranesp

[SoledadBarcelona]

Did you check your thyroides, vitamine D, B12, magnesium, etc? Sometimes we think that the medications are the problem but there are a lot of cases where the body cant work properly due to lack of minerals and vitaminas.

[Sprat19]

My haematologist has reduced my peg to 2 weekly to see if that helps with my falling neutrophils and RBC. As he put it platelets are falling well so don’t need to be so aggressive. Certainly less tired. Next bloods August

[Mazcd Partner MPNVoice]

hi Joe, I hope this is the slide you were referring to and is easier to see

slide

[MPNBlog]

I’m not sure about your reference to anemia and being tired (MPN’s themselves can cause ‘fatigue’). But I think the slide you are talking about is in this article (sorry I can't seem to paste just the diagram here), so you'll be able to see it clearly - Molecular analysis of patients with polycythemia vera or essential thrombocythemia receiving pegylated interferon α-2a - PubMed (nih.gov)

The simple answer to your question is yes - Pegasys doesn’t work for everyone. (I’d be a bit concerned if your haem doesn’t know that). As the table shows, 20% with ET and 21% with PV had no ‘haematological’ response.

The more complex answer is that different people respond differently to all drugs, and in addition, the response might change over time. Despite research to date it isn’t yet clear why some people respond to Peg and others don’t. In fact it’s not clear exactly how Peg works. The Interferon Initiative (by the MPN Research Foundation in US 2021-10-21-MPN-Interferon.FINAL_.pdf (mpnresearchfoundation.org) looked into these things and didn’t come up with a clear answer, concluding more research was needed.

Another question is what does it mean for Peg to ‘work’. There are multiple measures such as haematological response (your blood counts) and molecular response (the impact on your bone marrow). It can reduce the allele burden ie the number of mutated Jak2 cells. I am one of those for whom the reduction in allele burden has been slight – only 2 %. But at least it’s not increasing, which it might do without Peg. Some people can have the allele burden reduce from over 50% to less than 10%. At the present time it isn’t clear what that means medically.

Factors influencing the response to Peg include what type of driver mutation/s you have. Also the Peg dosage can affect the response (higher dose having a greater effect, but greater side effects). While the box and whiskers plot in the table you referenced shows the dynamics of the changes in allele burden, what it doesn’t state is that complete ‘molecular’ response only occurs in less than 20% of people, as it says in the article, and also here (PREDICTING THE LONG-TERM EFFICACY OF IFNΑ IN JAK2V617F AND.... EHA Library. Tisserand A. Jun 12 2020; 295034 (ehaweb.org) .

However, there are other potential benefits to consider with using Peg. It’s the only drug shown to have a disease-modifying effect and have the potential to reverse bone marrow fibrosis. And there is now research that in PV it has better overall rates of survival and lower rates of progression to MF than HU or phlebotomy alone: Paper: Interferon in Polycythemia Vera (PV) Yields Improved Myelofibrosis-Free and Overall Survival (confex.com) ASH 2019.

I think the Peg makes me more fatigued, but I’m tolerating it for the potential other benefits, even though it has had a minor impact on allele burden. But it's not for everyone.

I hope you get some more answers soon. Best wishes.