Urgent! Help deciding on Pegasys dose today

[IrishSarah]

Hi gang,

I have an appointment with my Haem in a couple of hours to prescribe pegasys and I’m trying to decide what the best starting dose will be. Would appreciate any input/advice you guys can give!

I’ve previously had great results on 90mcg weekly, moved to 90mcg fortnightly when my counts were well controlled. Took a year break while I was having a baby.

I’m trying to balance achieving controlled platelets & opportunity for molecular remission with minimal side effects.

I know the jury is still out re:achieving remission but I like to take the optimistic approach so let’s assume remission is a strong possibility.

My question is - what is the minimum dose of Pegasys required to effect remission?

I know the hard data isn’t there to answer my question definitively yet - but I need to go with the best guess today!

Thanks as always 💚

[hunter5582]

Many start on 45mcg/weekly, which is where i started While dose titration is often in 45mcg increments, some opt to increase dose by half that. Here i one of the NHS treatment protocols.

nssg.oxford-haematology.org...

Good luck with getting started back up.

[IrishSarah in reply to hunter5582]

That’s such a helpful document! Have saved for future reference. Much appreciated

[hunter5582 in reply to IrishSarah]

How did the appointment go?

[IrishSarah in reply to hunter5582]

Got the dosing worked out - starting with 90mcg fortnightly which will hopefully be a manageable balance between efficacy and quality of life. Then threw a spanner in the works when we couldn’t establish whether Pegasys is safe for breastfeeding. Prof Harrison has been asked to give input so hoping she has the answer. I had previously checked with a pharmacist with special interest in lactation (she writes books & guides for health service in the UK) and she thought it’d be safe based on studies on inf alpha2b. Baby won’t be too happy if she was wrong 😂

[hunter5582 in reply to IrishSarah]

Glad you got the dosing worked out to your satisfaction.

Breastfeeding while on Pegasys is definitely an issue to review with a MPN Specialist. As you can see below, what is in the literature is mixed. i would definitely seek guidance from a specialist well versed in Pegasys use.

Lactation Clinical Summary

avoid breastfeeding if nipples cracked or bleeding, otherwise may use while breastfeeding; no known risk of infant harm based on limited human data; no human data available to assess effects on milk production online.epocrates.com/drugs/...

Summary of Use during Lactation

Although no information is available on peginterferon alfa in breastmilk, the levels of conventional interferon alfa in breastmilk are minuscule. In addition, because interferon is poorly absorbed orally, it is not likely to reach the bloodstream of the infant. ncbi.nlm.nih.gov/books/NBK5...

8.3 Nursing Mothers

It is not known whether peginterferon or ribavirin or its components are excreted in human milk. The effect of orally ingested peginterferon or ribavirin from breast milk on the nursing infant has not been evaluated. Because of the potential for adverse reactions from the drugs in nursing infants, a a decision must be made whether to discontinue nursing or discontinue PEGASYS and COPEGUS treatment. accessdata.fda.gov/drugsatf...

Breastfeeding

It is unknown whether peginterferon alfa-2a/metabolites are excreted in human milk. Because of the potential for adverse reactions in breastfed infants, breastfeeding should be discontinued prior to initiation of treatment. ema.europa.eu/en/documents/...

Please do let us now what Dr. Harrison recommends. There are certainly other mothers who will be interested.

All the best my friend.

[Joetcalr in reply to hunter5582]

That’s very useful and clear information, thanks Hunter. But I’m puzzled, it says among very commonly reported adverse effects is anaemia, yet while I was on Peg I was told that my anaemia (I’m assuming that means low haemoglobin) was caused by a progression to MF, and even at the Forum in London in November a question was asked about anaemia being caused by Peg and the answer was no it didn’t cause anaemia, can anyone shed any more light here?

[hunter5582 in reply to Joetcalr]

Anemia is defined as a deficiency in hemoglobin/red blood cells. There are different types of anemia with different causes.

Myelofibrosis can cause anemia due to the fibrosis interfering with the ability of RBCs to be produced in the bone marrow. It appears that your care team's assessment was that the anemia you experienced was more likely due to the MF than the PEG. Your care team could give the best case specific answer to your question.

Pegasys reduces the production of all types of blood cells. That is why it is used to treat MPNs. It is possible to overshoot the mark with RBCs and induce anemia. This is refenced in the literature.

" PEGASYS can affect your bone marrow and cause low red blood cell, low white blood cell and low platelet counts. These blood counts may fall to dangerously low levels. If your blood cell counts become very low, you can get anemia, infections or have problems with bleeding and bruising. " rxlist.com/pegasys-drug.htm

online.epocrates.com/drugs/...

drugs.com/pro/pegasys.html#...

While there are other adverse effects that are more common with PEG, anemia is on the list. You will also find anemia on the list of adverse effects for other cytoreductive medications.

Hope that answers your question.

[Joetcalr in reply to hunter5582]

Thanks, having been on peg I’ve now been put back on a low dose of hydroxy, hopefully that will halt the anaemia.

It’s so true that everyone is different, I never got any flu like symptoms on peg just gastro stuff, mouth ulcers and tiredness. Jo

[hunter5582 in reply to Joetcalr]

Hopefully you will find HU works better for you. Do note that anemia is a possible HU adverse effect too. For people with MF + anemia the hope for the future is momelotinib, another JAK inhibitor. It show promise in the clinical trials. Hopefully, it will be approved soon.

Wishing you all the best

[Manouche]

Some get a remission (haematological) on low dose (45mcg), others at 180mcg…Everybody is different. Regarding molecular remission, a higher dose is generally better, if your body accept it. Weekly 90mcg injections seem to be the minimum dose to get a « quick » complete molecular remission. Some get a complete molecular remission in less than 2 years on such a dose.

[IrishSarah in reply to Manouche]

I thought that was the case so thanks for confirming! Really helped to put my mind at rest. Going with 90mcg fortnightly to start

[Ovidess in reply to Manouche]

How long do such remissions last? I have not read anything definitive on this.

[Manouche in reply to Ovidess]

Over 14 years in some cases

[bruddery]

good luck for today. Janice

[IrishSarah in reply to bruddery]

Thanks Janice!Just waiting for info from Claire Harrison re: safety for breastfeeding and hopefully I’ll be cleared to get started

[Wyebird]

congratulations on having a baby. Your reintroduction to Peg I assume would be 45 mcg but as for effective remission I’m sorry I have no clue. Your heamo will look at your FBC with you. Then jointly you can decide.

Good luck

[ainslie]

everyone is likely to be different but I recall Dr Mesa saying a few years ago that it is likely to need 90mcg to make a difference on the MPN, in a way you have sort of answered your own question if 90 weekly then fortnightly controlled your counts then maybe that’s the dose for you, as going higher will take your counts too low. Some believe 45 weekly is better than 90 fortnightly. However, if you are in touch with Clair Harrison she is the best one to ask for sure.

[Exeter21]

I started back on 45 monthly currently as weekly gave migraines. MPN Dr advised low dose till body used to it Julia Devon UK 👍