I took Zydelig for 3 months for Follicular Non Hodgkin's Lymphoma. I had a very serious adverse reaction to this drug resulting in Pneumonitis. I was hospitalized for a week and have never been that sick in my life. I almost died. After 2 weeks out of hospital, I had a relapse of pneumonitis. I can't breathe and no matter how many antibiotics and steroids I take, I am not getting better. I believe this is a dangerous drug and needs more research. BEWARE!