Ibrance vs. Verzenio (Abemaciclib)

trojansroy

What is the difference between these two drugs. My wife has Stage IV Her2+ Metastatic Breast Cancer that has spread to her bones, lungs and liver. She had surgery in 1997 to remove the right breast and had chemo and 5 years of Tamoxifen after and 20 years later it strikes again. Why? Her Oncologist recommended that she begin intravenous Chemo as her tumor markers are going up a bit each month and it appears Ibrance has failed after 2 1/2 years and went for a second opinion yesterday at the City of Hope and saw a Breast Cancer specialist who recommended stopping Ibrance and moving to Abemaciclib, which is generic for Verzenio. Aren't they all the same in this class?

vlnrph

Ibrance was the first CDK 4/6 inhibitor to hit the market five years ago so many oncologists choose it preferentially, having had the most experience with it. Like Kisqali, it is taken 3 weeks out of 4 because of the tendency to tank your blood counts. You get 7 days without drug to recover.

Verzenio, on the other hand, is dosed daily am and pm with no breaks. It allows your hematological profile to remain in a healthy range however is notorious for causing diarrhea. Take a read thru the article pinned to the top of that thread. I like the statistics on abemaciclib better: progression free survival, etc.

The question of succession is still being debated. There may also be hesitancy on the part of the manufacturer to provide co-pay assistance. Let us know how it goes.

pajim

palbociclib (Ibrance) and ribociclib (??) are basically the same. Cyclin-dependent Kinase 4 & 6 inhibitors. Abemaciclib (Verzenio) is also a CDK 4/6 inhibitor but much stronger on the CDK 4 than 6. It has (I believe and would need to look it up) a slightly different mechanism of action. Which is also why it has different side-effects.

And also why it may work if Ibrance has failed. Didn't work for me and there isn't a lot of data on this but I think it's a 30% chance of working. I consider that pretty good odds but would watch carefully.

I am a little confused about i.v. chemo though. They didn't suggest Xeloda (capecitabine) as a possible next step? I assume she's already taking one of the HER2+ medicines.

trojansroy

Thanks for your reply. My wife is currently taking Ibrance and gets an injection of Xgeva as well. Her rumor markers are going up and so we sought a second opinion for City of Hope and Dr. Lavasani who is a specialist in Metastatic Breast Cancer whereas my wife's Oncologist is not, so now together they will be working on her based on shared notes. My wife wants to retain her hair so we were looking for an oral chemo drug that would be less on that side effect. Her Oncologist, Dr. Quan, suggested my wife go on intravenous chemo due to the numbers going up. My wife is feeling fine other than some fatigue in the afternoons. She has no other symptoms at this time. Originally she went to our GP complaining of a back ache and he immediately had her go get an MRI and they found multiple tumors in her back, brain and lungs. She had a Gama Knife procedure on the three brain tumors and they are now gone completely. Her latest Scan shows the spread of the disease to her liver and a couple more small tumors in her lungs. These are all very small at this time. So, that is where we are right now deciding on further treatment and a new game plan since Ibrance is now officially failing. We were told it would work for about 2 years and that exactly what happened. Dr. Lavasani is suggesting my wife switch to combo of Tamoxifen and either Xeloda or Taxol. She also mentioned Abemaciclib, which is generic for Verzenio. Any feedback or suggestions would be appreciated from anyone.