Anyone with ET use Besremi?

[Mountainbiker12]

Pegasys is causing me significant liver enzyme increases.  I have high risk ET, CALR-1 and resistant to Hydrea. Pegasys has worked well for past 8 years but now liver can no longer tolerate.  Just wondering if anyone else has had this happen and what the change in cytoreductive management strategy was. Could Besremi be an option if Pegasys is causing problems?

[dbus1417]

I am not sure as I haven’t had to start treatment yet, but when I do my hematologist suggested besremi is what we would go with. I’m 39 ET CALR type 1 also.

[welshhuw]

hi, i had a similar problem with significant increase in ALT after about 3 years on Pegasys. I was very reluctant to stop altogether since my platlets were very well controlled on Pegasys, as were all my other blood results. Also, there is evidence that Pegasys may be disease modifying and may prevent progression. I took a month break from Pegasys then restarted at a lower dose and reduced frequency. I'm pleased to say, it worked, my ALT is almost in the normal range and platlets still well controlled. I can't comment regarding Besremi, but it is very similar to Pegasys (Besremi - monopegylated INF alpha-2b : Pegasys - pegylated INF alpha-2a) . Best discuss with your consultant, hope you can find a solution, wish you all the best.

[Hopetohelp in reply to welshhuw]

that’s great to hear the break worked and still figures controlled at lower dose

[hunter5582]

Sorry to hear about the issue tolerating Pegasys. I have done quite well on PEG and then Besremi after not tolerating/benefiting from HU.

Besremi is in clinical trials for ET. It is a very expensive medication and approval off-label for Et would be very difficult to obtain. Here in the USA, the most likely way to access it would be through the clinical trial. Note that there are also other drugs in clinical trials for ET such as bomedemstat. If you are interested, you can consult with your MPN Specialist.

As weishhuw suggests, it may be that taking a break from PEG then restarting at a lower dose may resolve the issue. You also have the option for consider Anagrelide or Jakafi. You would likely run into a similar insurance approval issue with Jakafi though,

Please do let us know what you learn and how you get on. All the best moving forward.

[Sam2022]

I was taking Pegasus at 90mcg/week and plate number is well controlled below 400. However, my liver had similar issue as yours (ALT and AST above normal range). Then I reduce the dosage and frequency at 75mcg/2 weeks, now every indicator in liver test show normal. The only current issue is my WBC and RBC are still lower than normal range. I am going to reduce frequency to 75mcg/3 weeks. You may try the same experiment with dosage and frequency to make your body readjust the Pegasus. Good luck!

[Mountainbiker12]

Thank you all so much. It was super helpful for my discussion with my MD. We agreed I would stop Pegasys until my liver enzymes drop to below 3 times UL. Then will restart at 45mcg/week. Will do weekly blood draws to monitor platelets and liver.