Besremi

[ERei]

Is Besremi used for ET or just PV?

I was thought to have PV due to being Jak2+ & having elevated hemoglobin/hematocrit levels.

When I had a bone marrow biopsy it was pretty much normal so I was then said to be MPN-U.

I am presently on HU 500mg every other day. My hematocrit & hemoglobin are now on the low side of normal.

There had been discussion of me going on besremi when I was thought to be PV. I am now wondering if I have ET if besremi is still an option for treatment or does it only treat PV?

[hunter5582]

Besremi has an FDA indication for PV in the USA. It is in clinical trial for ET, but would be off-label for ET at this point in time. It sounds like you current diagnosis is MPN-U rather than ET, however.

Reference the WHO diagnostic criteria for PV.

Diagnostic criteria for PV as per the 2016 revised World Health Organization (WHO) guidelines include three major criteria and a minor criterion. Diagnosis requires the presence of either all three major criteria or the first two major criteria and the minor criterion. [5]

Major WHO criteria are as follows:

1. Hemoglobin >16.5 g/dL in men and >16 g/dL in women, or hematocrit >49% in men and >48% in women, or red cell mass >25% above mean normal predicted value

2. Bone marrow biopsy showing hypercellularity for age with trilineage growth (panmyelosis) including prominent erythroid, granulocytic, and megakaryocytic proliferation with pleomorphic, mature megakaryocytes (differences in size)

3. Presence of JAK2V617F or JAK2 exon 12 mutation

The minor WHO criterion is as follows:

1. Serum erythropoietin level below the reference range for normal

Since you do not meet the major criteria in terms of Major Criteria 2 - bone marrow morphology, you would have to meet criteria 1 and 3 along with the minor criteria of low EPO to receive a PV diagnosis.

This matters since it can be difficult to get Besremi approved even when you do have PV due to the expense. It would be very difficult to get Besremi approved for MPN-U.

Is there a need to switch from the low dose HU you are currently using? If so, it would likely be much easier to get Pegasys approved due to cost difference. This would be something to discuss with a MPN Specialist who knows your case.

Wishing you all the best moving forward.

[ERei in reply to hunter5582]

Thanks Hunter! Your responses to everyone are always so helpful <3

My EPO was low when tested initially back in 2019. My hemoglobin & hematocrit were also high...since they are now low (just under normal range) & going down, I no longer meet the criteria for PV (as well as a normal BMB). I was approved for besremi a ew years ago but was hesitant to go on it. When last discussed, my MPN doc felt besremi is the best option for me to eliminate the possibility of progression but am now unsure since my hematocrit/hemoglobin are low & looks like I may be heading towards ET??? My platelets were once high but they are now normal so not sure which MPN I even have at this point

[hunter5582 in reply to ERei]

The fact that your blood cell numbers are controlled on cytoreductive medication does not change your diagnosis. That is the point of the treatment. It is your baseline that matters diagnostically. It is worth noting that PV or MPN-U can include thrombocytosis as well as erythrocytosis (and possibly leukocytosis).

The rationale for switching to Besremi makes sense provided it is consistent with your treatment goals and risk tolerance. Preventing progression is a worthwhile goal to pursue and the evidence for Besremi helping to achieve this goal is favorable. This is one of the reasons I chose Besremi. I also tolerate Besremi much better than HU and it is more effective at maintaining a hematological response.

It is hopeful that you were able to get Besremi approved in the past. Hopefully, you will find it possible to have approved again if you decide to move forward with it.

[PhysAssist in reply to ERei]

Hi ERei,

In agreeing with Hunter, I would say that an analogy is that if you are diagnosed with hypertension [high blood pressure] and put on antihypertensive medications that control your blood pressure effectively, it doesn't mean that you no longer have high blood pressure, it's just being effectively managed.

In addition, if you were able to get insurance approval in the past for Besremi, it should be a slam dunk to get re-approved- the previous approval doesn't get negated just because you decided to try another course of treatment- and having your MPN MD on board and recommending it should make it even less of a struggle.

Finally, the 2nd major criterion related to BMB exemplifies Hunter's comments about having elevated white and red blood cell, and platelet counts- it's what defines PV, and in my opinion, MPN-U may likely be early PV that hasn't fully developed yet.

ET on the other hand seems to be pretty much limited to just elevated platelet [thrombocyte] levels.

Best of everything,

PA

[ERei in reply to PhysAssist]

Thanks so much for your clear explanation. It makes so much sense to me now!

[Wyebird]

Hi I’m slightly confused. You do not mention your platelet levels and if hemoglobin/hematocrit levels are now on the low side why isn’t your medication being reduced.

[ERei in reply to Wyebird]

My HU was reduced from every day to every other day. We tried to reduce it to every 3rd day but although my #s were still good I became symptomatic (leg cramps & sweats) so went back to every other day. I am now trying every 3rd day again to see what happens. I asked my MPN doc if I am in danger of progression since my #s are looking good on a low dose of HU and he replied that unfortunately there are no studies on this so he doesn't know but thinks Besremi is still a good idea

[Wyebird in reply to ERei]

I do hope you stabilise

[monarch5000]

We can't say much without seeing numbers and hearing more about your symptoms. Jak2 allele burden %? EPO Blood Test number? Amount of reticulin fibrosis (None, mild, moderate, severe). RBC/HCT/HGB/WBC/RDW/MCV/Platelet blood counts at diagnosis vs now?

Besremi is one brand of interferon-alfa, but there are others such as Pegasys. Interferon-alfa can be prescribed for PV, ET and early MF.

I'm not a doctor, but so far it sounds like you have a super mild case of PV (since it was controlled using a super low dose of HU) that could be controlled using only small, infrequent doses of Besremi or Pegasys that have few to no side effects.

Seems rather ridiculous to use a $16,000 a month medicine like Besremi for such a minor case of PV and more sensible to use a $1,100 one ml vial of Pegasys and to get three or four 1/4 ml doses from each vial.

[Anag]

Besremii is being tested for ET and it looks promising. I have ET CALR and have been on it because I can't tolerate HU and Anagrelid has caused me heart problems. The insurance let up after struggles with my adamant MPN specialist. : ) At the last MPN Seminar I was at last September in Vienna, Dr. Gösslinger said that it takes the longest to work for those with ET CALR. Dr. Buxhofer-Ausch said that it's important to go on the Interferons early on because it's the only way that the illness could be brought into remission, at least for several years.

It took 9 months for Besremi to work properly, but once it kicked in, my thombos plummeted to normal after 14 years! I reduced my Anagrelide slowly during that time as the PLT was going down. I am still taking just one a day. Over the years, the intolerance slowly got worse.

With the now well-functioning Besremi, all my old accidents started hurting, more the tendons than the joints themselves. It became so bad, that I had to stop for 2.5 months, my thrombos started to climb slowly and I restarted at a 1/4 the dosage (50mcg instead of 200) now on 75, the next shot at 100. just had my blood test done, PTL 535, so all is going well with 75mcg! After speaking to my MPN specialist we agreed that I up my dosage to 100mcg and the last Anagrelide that I'm still taking will be cut, hence finally rest for my heart after 6.5 years! FINE-TUNING OUR MEDS IS CRUCIAL!

My opinion regarding overall health, for every single person who's on any medication, a fine-tuning of nutrients, and an absolutely clean, non-GMO, organic, anti-inflammatory diet make a huge difference in health and quality of life!! Also reducing or better, stopping ALL chemicals in the home works wonders.

Hope to have helped

Anag 🙂