Ibrance (Palbociclib)

cowgal. I have been on for 3 years and was told I would remain on it for as long as I didn't have evidence of toxicity or progression.

per ChatGPT

Short answer: I’ve seen very few people taken off Ibrance solely because “it’s been too long.” That rumor pops up every couple of years and then quietly dies when you look for actual evidence.

What’s actually known

• Ibrance (palbociclib) does not have a defined maximum duration. In metastatic HR+ breast cancer, the rule is brutally simple: stay on it as long as it’s working and tolerable.
• There are real patients on 7–10+ years of Ibrance. They exist. They’re usually boring case reports because boring equals stable disease.
• Long-term follow-up from PALOMA trials and real-world cohorts has not shown cumulative organ toxicity that forces discontinuation at a set time.

What can happen over long durations:
People are sometimes taken off Ibrance after many years, but usually for one of these reasons:

• Chronic cytopenias that stop recovering even with dose reductions (especially neutropenia or thrombocytopenia)
• Recurrent infections that become unsafe
• Quality-of-life erosion someone decides is no longer worth it
• Very rarely, bone marrow fatigue where counts never bounce back

That’s not “toxicity from being on it too long.” That’s individual tolerance hitting a wall.

What I have not seen

• No guideline saying “stop at 5, 6, 9, or 10 years”
• No oncology consensus saying long-term CDK4/6 inhibitors are inherently dangerous
• No data suggesting elective discontinuation while NEAD improves outcomes

I will have been taking Ibrance 5 years come next month. I am stable.

Shirley