Anyone else experience worse side effects on Besremi as compared to Pegasys?

[monarch5000]

I have PV and used 90 mcg once a week for 5 1/2 years with good blood count control and only minor side effects (slightly dry eyes, slight flu like symptoms the day after injecting. In January 2022 I switched to Besremi and used a 150 mcg dose every 2 weeks. Since January there has been no change in blood count results as compared to Pegasys, but the side effects of Besremi have been substantially worse; i.e. very dry eyes, skin and hair, pronounced flu like symptoms and general physical lethargy that lasts several days and lots of joint aches. I have decided to switch back to Pegasys to restore my quality of life without sacrificing good blood count control. Anyone else feel better on Pegasys as compared to Besremi?

[Meatloaf9]

Sorry to hear you are having trouble with Besremi. Glad to hear that you did well with Pegasys. I guess you can always go back. Besremi is so new that I think we will hear of those who have problems with the Besremi as time goes by. Possibly the side effects you are having with Besremi will subside with time. It was hyped so much from the beginning that everyone, I think, expected it to be a miracle drug. I think all drugs have pros and cons and the longer it is used the more valuable information we will obtain. Thank you for sharing your experience, I am on HU and would like to try Besremi. A reminder that we are all different and what works for one may not work for all. Best of luck to you going forward.

[jon1972]

I feel the same way as you about Besremi. I've had the dryness issues with my eyes while on Peg (mainly at night), but it's worse now. I've also noticed my skin drying and extreme thirst all the time. It seems Besremi is more potent, possibly what allows it to stay in your system longer? I've also had a lot of muscular and joint pains since being on it, although I can't confirm it was caused by the Besremi. So far Besremi has not been effective in controlling my counts either. I needed right around 135mcg of Peg to control my HCT, and so far 200mcg of Besremi is not cutting it. My HCT just spiked to 47 requiring a phlebotomy. I hope I don't have to up the dose much farther with the increased side effects, but I'm not ready to throw in the towel and go back to Peg just yet. I had to look it up again, but Dr Ruban Mesa had a titration schedule for Peg to Besremi as follows: Add up the montly dose i.e 90mcg x 4 weeks = 360mcg/mo. Multiply by 0.7 and divide by 2. So 360 x 0.7 = 252, 252 / 2 = 126 every 2 weeks.

So in my case of 135mcg / week. 135 x 4 = 540 / month

540 x 0.7 = 378

378 / 2 = 189 / 2wks

In theory 200mcg every 2 weeks should be sufficient for me, but either my counts just haven't stabilized yet, or these figures are just loose estimates. I'm going to be upping to 250mcg the next dose if my WBC's aren't too low.

[monarch5000 in reply to jon1972]

Jon, very interesting to hear your experiences with Besremi have been identical to mine; i.e. substantially worse side effects compared to Pegasys plus less effective control of RBC/HGB/HCT counts.

Two days ago I had a CBC done and my HCT was 51 ! For 5 1/2 years on Pegasys it never got higher than 49. Also, 2 days I gave myself my first 90 mcg shot of Pegasys after quitting Besremi 13 days ago and I'm rapidly getting back to feeling my formerly more energetic and ache free self again.

[EPguy in reply to monarch5000]

There is a post from member lynxfluff reporting worse fatigue on Bes.

healthunlocked.com/mpnvoice...

And there are two in this thread are seeing lower quality blood control.

I'm still on 50mcg of Bes, and it seems to be working, but only ~1.5 months so far.

Your result with reverting to PEG is compelling and clearly something is going on.

Do you know which mutations you have and %? No idea if it's relevant but maybe we can look for any pattern.

Several members have reported improvements on Bes, it's always gray areas in our journey.

Bes and PEG actually use different INF formulations in addition to their different pegylation methods, PEG: INF alpha (a) and Bes: INF alpha (b). I tried to ask the mfg why they chose (b) but no surprise, they're not telling.

The old PegIntron used (b) and some studies had it less effective than (a) I've posted on that.

[monarch5000 in reply to EPguy]

Jak2V617f mutation with 36% allele burden when first diagnosed in 2015.

[EPguy in reply to monarch5000]

Did you get any alleles since then? It should at least not increase while on INF.

[EPguy in reply to monarch5000]

There seems to be a pattern of low WBC and less strong effect on HCT with Bes. Your max HCT on PEG was high for MPN too. It's possible Bes combined with Rusfertide (the effective PV iron control med in trials) could get a better balance.

I don't think it's been tested this way, but might be something if/when Rusf is approved.

[jon1972 in reply to EPguy]

I have struggled with both Peg and Bes on controlling HCT while keeping WBC's at a minimum threshold. The WBC's always seem to eventually recover, but it's definitely a balancing act. I just spoke to my specialist and he said if my HCT is over 44 that's key to up the Bes by 50, but to only do so if my abs neut. is over 1.2. Hopefully I'll find the magic # like I did with Peg when I held stable counts for the past year.

[EPguy in reply to jon1972]

Do you get a feeling Bes will be harder to control this balance? It's likely early to judge this clearly. The Rusfertide guys could have find good future market with some INF users. On HU, HCT usually stays controlled easier than what INF is looking like so far.

[jon1972 in reply to EPguy]

I have no idea how Besremi is going to work out for me yet, but I'm trying to stay optimistic. I just think it's too early to give up on it considering it took me 2 years to find the right balance with Peg. I do think some of the side effects are worse, especially the dryness and mucous, but there are also some that are not as bad like the low back pain and GI upset that I had with Peg to be fair. I'm very interested in the Rusfertide, but I'm not sure it's been approved yet, and I'd prefer to stick with just the INF if I can get away with it., especially considering how new Rusfertide is.

[EPguy in reply to jon1972]

If it's 2 years to get PEG pegged, some time for Bes is for sure needed also.

I've not had these symptoms yet on Bes, but I'm only 4 doses in at only 50-70 mcg.

Rufs is still in trials so its only for the future. But based on these recent INF discussions on the Voice it comes to mind.

[gvibes in reply to jon1972]

Interesting sidebar at least for me. I also struggle with low white cells while controlling high reds and been on pegasys for a year. I looked into Rusfertide trial but didnt qualify at the time. My diagnosis is based on the exon 12 mutation not the usual v617f, and generally people with this mutation have high reds but pretty normal whites and platelets (which presents problems for cytoreductive treatment). My doc has mentioned rusfertide as possibly used in conjunction with a low dose of interferon for these kind of situations.

[monarch5000 in reply to EPguy]

I think the bottom line is that just as more Peginitron users (interferon alfa-2b) used to report more intense side effects, on average, than Pegasys users (interferon alfa-2a), with no corresponding reward like improved normalization of blood counts, I think the same pattern may prove true in regards to Besremi (interferon alfa-2b) vs Pegasys.

In other words, a sizable chunk of Pegasys users who switch to Besremi may end up wanting to switch back to Pegasys because they experience distinctly more deleterious side effects on Besremi with with no corresponding reward like improved normalization of blood counts.

[EPguy in reply to monarch5000]

The big improvement with Bes was to be its pegylation control. It will be interesting if the type of INF they selected ends up being an equal or greater factor.