Hi @sharonm2023. Welcome to Connect. I promise you won’t be alone here! There are quite a few members who have multiple fibrosis or one of the other blood conditions associated with the CALR mutation such as polycythemia vera or essential thrombocythemia.
You may have already read the links to articles I provided for @rhollis in this comment… https://connect.mayoclinic.org/comment/1201587/

If not, take a few minutes to read through.
There are medications available to slow the progress of the fibrosis to the bone marrow, but ultimately, a bone marrow transplant remains the only cure for this condition. A good friend of mine, whom I met while we were both having our bone marrow transplants in 2019, had MF. She is now 5.5 years post transplant like me, and is doing well. Perfectly healthy and no signs of the MF returning.

I know you’re concerned about your hemoglobin levels after you’re out of the clinical trial. That can be a side effect of the disease itself. With a clinical trial you don’t know if you’re on a drug or a placebo. So your blood numbers may not change after you’re out of the trial if you’re on the placebo. Right now, active surveillance would be appropriate until you know. If your numbers start changing in the future and your current hematologist is reluctant to explore any other treatment options, it may be in your best interest to seek 2nd opinion with a larger teaching/research hospital such as Mayo Clinic, Cleveland Clinic for examples…
In the meantime Jakafi is one of the standard medications for MF and has a good track record. Are you having any side effects from the medication?