increase dose peg and increased spacing

[Sprat19]

I am just trying to prepare myself for my appointment this week where no bou t the Peg shortage will be brought up. Currently on 45 ug Peg every 3 weeks. If I go to 90ug every 6 weeks I have enough in the fridge to last 18 weeks however my wbc is always low and last neutrophils were 1.5. Wondering what the big hit of 90ug would do to this , or actually would it be a beef it having bigger spacing and more time for one marrow recovery.

[Mishie14]

I have been on peginterferon for 18 months. Started low dose 45 biweekly then 68 and now at 90 weekly. The gradual increase is because I am very sensitive to these drugs. Slow increase allows time to adjust. I skipped weekly dose twice this year due to travel. Did not feel badly at all while traveling. Blood tests upon return showed platelets wavered as did 2 liver enzymes. Second test after returning had numbers back to my current normal. We react differently so you may need to try changing dose and timing to see what happens. Of course your treatment team needs to be on board. Good luck.

[hunter5582]

It is hard to predict how any one person will respond the the differing dosing schedules.

One factor to consider is the half-life of Pegasys = 80 hours. This means that at 80 hours 50% of the PEG is still in your system. 160 hours = 25% (roughly 1 week) . 240 hours = 12.5% 320 hours = 6.25% (roughly two weeks). As the levels drop below a therapeutic level, Pegasys loses efficacy. The premise of any dosing schedule is to maintain a therapeutic dose based on each patient's needs. You would need to discuss this issue with your MPN care team to get the best case-specific feedback.

Spacing out the Pegasys dosing could cause your blood cell levels to cycle up and down in a more dramatic fashion. Likewise any adverse effects you may experience. You may experience adverse effects at the time of the higher dosing that you did not experience before. Or you many not. There may be not way to predict this.

Regarding low WBCs (leukopenia) the answer is it depends. Some degree of leukopenia is common with Pegasys. Your body can still respond adequately to an infections provided the levels do not fall too low. Not all WBCs are the same. My care team has set the goal of NEUT>1.00 and LYMPH>0.50. Suggest you discuss specific leukocyte goals with your care team so you know what the parameters are.

The bottom line is that 45mcg every three weeks is not the same thing as 90mcg every 6 weeks. Whether this would be a viable plan for you is something to discuss with your MPN care team.

Wishing you success moving forward.

[Jynx93]

ET Jak-2. I have just had my peg dose changed from 45 weekly to 90 bi weekly. I took 90 by mistake last week, I must concentrate more when I take it. I was fine and just felt really tired for a couple of days. I was told my NHS trust have supplies for those already on peg but new patients aren’t being prescribed until the shortage is sorted out.

It would be a lot less wasteful if these companies made syringes of 45 and we didn’t have to put the other 45 in the bin

[light in reply to Jynx93]

Hi there, Just wanted to ask you if you don't mind, where are you? Which NHS trust you are with? Wishing you well.

[Jynx93 in reply to light]

I am under Bristol and Weston health trust. I know some are having problems with getting Peg but I don’t appear to be. I have another prescription waiting to be collected. I hope everyone who is taking it can get theirs without changing to another medication.

[light in reply to Jynx93]

Yes, indeed, me too. Thank you.

[AndyT]

I have been on 45mcg every four weeks for the last few years and recently changed to 90mcg every eight weeks to reduce wastage and get my supply of Pegasys to last longer.

I was apprehensive about the change but a recent blood test at eight weeks (after my final 45mcg) showed that my counts were all in normal range and that my platelets were no higher than they would normally be at four weeks after a 45mcg dose. I also had no side effects from the higher dose.

I’m therefore going to continue with the higher dose and longer interval, with regular monitoring.

While previous studies have not fully demonstrated molecular remission after long term use of Pegasys, I’m hopeful that after being on it 9 years my platelet production may have slowed, allowing the longer interval to work and maybe even a return to a lower dose every eight weeks if all remains stable.

Hope your appointment goes well.

[Sprat19]

Thanks everyone. My MPN specialist is happy so long as my neutrophils are above 1.0 but really prefers over 1.5. At the moment I am trying to put my questions together to understand if the suggestion of 90ug 6 weekly comes up. Of course I don’t know what my bloods will show on Thursday yet.

Agree re syringe size. 45ug would make alot of sense. I would also be happy with multi dose vials and just draw up whatever I need at appropriate intervals.

[PolyVera]

I now take Pegasus 90mcg every 3 weeks. I was diagnosed in 2019 and to start with it was 45mcg and then later 90mcg a week. Over the last few years I have changed how often I take it after reading peoples posts on here. Everything is going good and my doctor is happy with my blood results. I thought I was pushing it with 3 weeks but others have bigger intervals and are managing well

[Sprat19]

update. Seen yesterday. My platelets have been increasing on 45 ug 3 weekly so it was decided to go to 90ug every 4 weeks which I am happy about. My wbc had also risen ( no longer neutropenic)Also got a supply of Peg. Also happy about. My hosp is getting 50% of its previous allocation.