Hi, Vicky, I am 70, CALR+, have had ET for about 15 years. Doing OK, no clots, fatigue is my main issue, but we are all different. I actually felt better when I went on HU. Many patients do.

CALR was only very recently discovered as a driver mutation and it's rare. But generally CALRs are less likely to clot than JAK2s. Your hematologist should be able to assess your individual clot risks by looking at your age, clot history, mutation type, and other contributing factors like smoking, drinking, family history, obesity, etc.

You may want to ask your doc if progression to myelofibrosis or leukemia is different for CALR patients. I don't know but researchers were looking at that.

Good news is that CALR is not associated with polycythemia vera, so progression to that can be scratched off your worry list.

In VERY general terms, CALR patients under age 60 often just take aspirin, and docs may let platelet levels approach 1,000. The danger of running over 1,000 is acquired von Willebrand syndrome (avs), which can cause internal bleeding.

Yeah, weird that a disease that carries clot risks also causes bleeding, but welcome to the weird world of ET.

I don't know if this addresses yr concern about titanium oxide, but some ET patients I have talked to who have dye allergies get their HU in clear gel capsules. You could ask yr doc or pharmacist about this.

That's all I got. Hope some might be helpful.