Hydroxyurea vs Agrilyn

I’m a 71 y/o male with ET. Diagnosed in 2015 with all the requisite tests including bone marrow biopsy. I have the CALR mutation. I have been on HU for over 10 years. At first I had ankle ulcers but they subsided within 6 months. I have been taking 1000 to 1500 mg of daily doses for almost 10 years. This year my platelet count started to bounce around from 400 to 700 without any apparent reason. It’s very peculiar. Sometimes it would go up with 1500mg and then go down with 1000 mg. My doctor took me to 2000 mg daily and my ankle ulcers reoccurred after two eeeks. We went back to 1000 mg daily and slowly the ankle ulcer healed after going to wound care and stopping treatment for about three weeks. Platelets still hovered in the 500 to 800 range bouncing back and forth every two to 3 weeks.

My doctor took me off of HU for 6 weeks and now wants me to consider Agrilyn. I’m reluctant going from the devil I know to a new drug. It appears that I can tolerate up to 1500 mg of HU daily. My only issue with HU has been slow to heal ankle wounds (which I’ve been able to manage). I had some fatigue but in the past 6 months my GP noticed a vitamin D deficiency and has had me on supplements. This has almost eliminated my fatigue.

Has anyone switched from HU to Agrilyn? What’s been your experience and side effects and how effective has it been in reducing counts? Also what is your typical dose?