Pegasys not working as well with Calr

[Joetcalr]

At one of the recent webinars from the US, a haematologist mentioned that interferon doesn't work well with Calr mutation. Can anyone shed any light? Sadly that seems to be my experience, but I think my haematologist might not know about that research. Thanks Jo

[hall2]

I’ve never heard this. I’m CALR2 and Peg has been brilliant for me.

[Joetcalr in reply to hall2]

Thanks Hall2, good to hear, maybe there are different calrs, I don't know which mine is. Jo

[JojoWonder]

Hi Jo,I’m also ET Calr mutation. I’ve been taking Peg interferon for coming up to 3 years. To start with my platelets were touching 1200 but they are now comfortably in the 200’s with one injection weekly. It was a slow acting drug for me and I was on hydroxy as well for six months which helped to kick start the decline in my platelets. I get on well with it with minimal side effects.

I haven’t heard that interferon isn’t as effective on our mutation but what I do know just from being on this forum is that it’s important to have bespoke treatment as we are all so different. I wasn’t a fan of hydroxy personally but many people take it without complaint. What is important to note is that peg interferon is a slow acting drug so it can take a while for it to impact.

Good luck and feel free to reach out if you have any questions.

Best wishes,

Joanne x

[Joetcalr]

Thanks Joanne, I've been on Pegasys for a year now, maybe it's just not suiting me. Jo

[robbjoy in reply to Joetcalr]

It took me two years on Pegasys to see normalization with blood counts. I am Jak2. Keep at it.

[Joetcalr in reply to robbjoy]

Thanks for the encouragement. Jo

[AndyT]

I am CALR+ve and interferon (Pegasys) has worked very well for me. I’ve been on it 6 years with very few side effects and great control of my counts.

[Joetcalr in reply to AndyT]

That's good thanks Andy what dose are you on?

[AndyT in reply to Joetcalr]

I started on 45mcg weekly, then increased to 90mcg.Once my counts were stable we began to extend the interval to 10, 14 then 28 days to see if that still kept them under control.

When that was working OK at 28 day intervals, we dropped the dosage to 60mcg then 45mcg.

For the past few years I’ve just been on the 45mcg every four weeks as a maintenance dose, which keeps my platelets around the 300 mark and avoids my other counts dropping too low.

[Joetcalr in reply to AndyT]

That sounds so organised and thought through. I've been on 90 per fortnight for a year, not keen to take more because of side effects, it is working fairly well, but haemoglobin gone very low. I'll see what my next bloods show.

[AndyT in reply to Joetcalr]

Thanks - I’m lucky to have a very proactive haematologist who’s always looking for ways to reduce medication while still achieving the best outcome.

Next step is to retest for CALR in the hope it may have reversed - that’s apparently less likely than with JAK2, which may have been what the haem you originally quoted was referring to - but still worth checking..!

[Joetcalr in reply to AndyT]

Thanks Andy, useful information. Cheers Jo

[EPguy]

In the reports below it is suggested you may need more PEG for CALR vs JAK2 so you might discuss your dose with your haem. The 2nd report says having additional mutations is a negative. The implication I get is these added clones are of more significance than with JAK2, but it does not actually state that here.

There are also different categories of CALR but I don't see that addressed in these reports.

nature.com/articles/s41375-...

<<...our data suggest that, clinically, higher doses of IFNa are needed in CALR-mutated vs. JAK2V617F-positive patients>>

and in:

pubmed.ncbi.nlm.nih.gov/264...

<<The presence of additional mutations was associated with poorer MR on CALR mutant clones>>

[Joetcalr in reply to EPguy]

Thanks for the info Glad I didn't imagine it all! just wishing the interferon would work better for me. Jo

[gilded]

I’m CALR positive ET and Pegasys is working well for me ( began it about 8 months ago).