Ruxolitinib - declining efficacy?

[Rob58]

Hi everyone

I’ve had PV for 12 years or so and have been on Ruxolitinib for the past 7 years with great success. My platelets dropped to around 450 and my haematocrit has been stable, with no side effects. My general health and fatigue levels have improved markedly. However over the past 18 months my platelets have been increasing despite increases in my Ruxi dose from 20mg per day to 40mg per day. My platelets are now over 600. My other blood counts remain within range.

I don’t have any particular symptoms but I’m now worrying whether the benefits of Ruxi are diminishing, and wondered if there’s anyone out there who has had a similar experience? And what happens after I reach the notional maximum dose of 50mg per day?

Grateful for any thoughts. Thanks, Rob

[hunter5582]

Sorry to hear about the increased thrombocytosis. This is something to review with a MPN Specialist for an accurate interpretation of the significance. While it is possibly a change in the MPN status, you would want to rule out any causes of reactive thrombocytosis as part of the assessment.

While worrisome, it is worth noting the increased thrombocytosis does not necessarily indicate increased risk of thrombosis. There is not a linear relationship between the number of platelets and thrombosis. The higher risk factor for those with PV is the erythrocytosis, which you indicate is still well controlled.

Any change like you are experiencing needs to be explored prior to making treatment decision. There are a variety of options should you determine that the benefits of more aggressive treatment justify the risks. In addition to going to the maximum dose of ruxolitinib, combining different cytoreductive agents is an option; however that option is one to be used with great caution. It would also be an option to switch to another treatment like Besremi. You may respond better to a different approach. All of the above is something to review with a MPN Specialist.

Please do let us know what you learn and how you get on.

[Rob58 in reply to hunter5582]

Thanks Hunter. I’m being carefully monitored by the excellent team at Guys so I’m in good hands. I think they’re also slightly puzzled by the increase. And as you say not yet too worrying…

[EPguy]

As hunter suggests, IFN may be worth discussion with your Dr if non-MPN causes of the rise are ruled out. I'm on Rux and counts are ok. But IFN held my PLT lower. Another option is Rux and IFN together. This can allow a lower dose of each to offer the best of each. But insurance coverage for both can be a problem.

Have you been getting mutation tests (Jak2 allele or VAF)%?

[Rob58 in reply to EPguy]

Thanks. I had an awful experience with interferon so not envisaging that as an alternative in whatever form. What are mutation tests?

[EPguy in reply to Rob58]

Understand on the terrible IFN experience, see my post "Last Dose" for a worst case outcome. What was your adverse reaction (u'stand if you prefer not to say)

Mutation tests are checking for the Jak2 mutation, and its level in %. Also checking for any others, for example TET2, dnmt3A etc. If you're at Guys they have likely done these checks. Reason I ask is there could be a relation of your response to changing mutation levels or types. It might not change your therapy right now but is worth knowing for future reference.

[Rob58 in reply to EPguy]

My reaction to Peg? Huge weight loss, severe fatigue, poor concentration levels…Everyone thought I was at deaths door I was so grey and down!

Thanks for the heads up about the mutation tests. I’ll check when I’m next at Guys…

[monarch5000 in reply to Rob58]

Next Generation Sequencing Mutation Tests give you a window into your future as they detect the presence (or absence) and allele burden percentage of secondary mutations that are associated with disease progression to secondary myelofibrosis, acute myeloid leukemia, MPN/MDS cross over, etc.

[monarch5000]

Since Rux is mainly used for myelofibrosis there isn't alot of data yet to know the fate of PV patients who have taken it for 7+ years.

It is well known, however, that taking a low-moderate dose of Pegasys interferon + a low to moderate dose of Rux, in combination, is usually highly effective at controlling blood counts and slowing or halting disease progression. I don't know, however, if the government in the U.K. is receptive to the covering the cost of both together.

If the combo is not obtainable then alternative therapies are to consider are Pegasys or Besremi interferon by itself or stopping the Rux for a month or two then restarting it. Some myelofibrosis patients who became resistant to Rux have reported it became effective again after they took a vacation from it.

[Rob58 in reply to monarch5000]

As per my deploy above I had a terrible time with Peg interferon and won’t be revisiting that any time soon!

[ainslie]

how long have you been on the higher dose, did you go from 10 twice a day to 20 twice a day suddenly or a gradual increase. Of course there maybe other reasons for increased platelets.

I am on 20 +17.5mg Rux since about 6/7 years, all counts steady with platelets at 200. Any expert I have spoken to and the last one was Mount Sinai in Oct they said there was no current evidence at that time of Rux losing effectiveness for PV.

It’s interesting your platelets rose but not Hct or whites, I would speculate that if Rux was losing effectiveness then whites and reds would also be rising. ?

As Hunter said 600 is no big deal for platelets unless other health issues or symptoms, before I started Rux my platelets were 600, on Rux they rose to 740 for several months and the slowly fell to 200.

[Rob58 in reply to ainslie]

Yes Ainslie I agree, I’m also puzzled that none of the other counts are shifting, esp the haematocrit, so perhaps I’m worrying unnecessarily.

[ainslie in reply to Rob58]

When you doubled your dose of Rux did it not lower your Hct and whites a lot, doubling the dose is very unusual

[Rob58 in reply to ainslie]

No it didn’t have any noticeable impact on those counts….

[sbs_patient]

I was diagnosed with PV 9 years ago and have been on Rux since August 2022, starting at 10 mg twice a day. This brought my blood count numbers down but also made me anemic. Reducing the dose to 10 mg once a day cured the anemia, and blood counts have also been stable, although WBC counts have been in the 15-18 range. Lately I've noticed that night sweats are back, though not as bad as before I started Rux, and there has been some weight loss (perhaps 5% of body weight over the past five years). My (non-local) MPN specialist wants to increase my Rux dosage to 10 mg AM, 5 mg PM. Unfortunately my local hematologist (who issues my prescriptions) is out of the office so it may take some time for this to be put into effect.