After two years on IBrance , going from 125 mg to 100 mg because of low neutrophils and still not being able to restart after a week off, I had researched the advantage of using the 5/2 schedule. My main goal was to avoid the terrible lows that lasted as much as 5 -7 days, leaving me weak, depressed and worried. So I tried this new schedule and here is the first month’s report.
1. The new schedule started after a two week recovery period. After the first 5 days I was feeling no side effects and stopping seemed unnecessary..but no pills that Saturday and Sunday.
2. Restarted the second week and again there were no real side effects..
3. Third week, again, no impacts, except that I was starting to feel a tad tired and more breathless by Friday but by Monday everything felt better.
4. No last week woes. No extreme fatigue, no depression, and I played lights out on a golf tournament.
5. My blood work on day 28 (Monday) was no surprise: neutrophils were right where they always were at 1.0, when I was able to restart after a recovery week. And just to add, my other blood numbers were all in the “green” area…so win-win.
I’ll be seeing my ONC later this week for the monthly check in but so far I’m so relieved that I can do this schedule without those awful wild swings in fatigue and mental state.
An added note about the CEA markers…they had been fluctuating this past summer and still are…ONC says to keep an eye on trends, not individual fluctuations. Right now, I’m crossing my fingers and thanking God that things are holding together. And IBrance is in me regularly and more consistently.
Next up: how long will I be able to do this 5/2 schedule without any recovery week? Will this continue to work therapeutically against the cancer? The data in recent trials of this schedule showed it was effective and highly tolerable… as good as IBrance is in the fight against MBC, it can’t be real good if it breaks down your body and kills your very desire to keep going.
Hope this helps all those who wanted some feedback on this IBrance schedule…I wanted to link this back to my original post last month but I couldn’t even find my own post. 😜
Best wishes to you all…🥰
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I’ve been rooting for this all along and I told my onc. this is what I wanted to do and it’s been fabulous for me! I had even wanted to start with 75mg but oh well!
I don’t understand why my oncologist doesn’t try this with all her patients who are struggling so badly but they do only what they know and the manufacturer’s dosing. Changes are so slooooow.
My onc was also very reluctant ! I was adamant after experiencing the extreme lows and having to wait two weeks to restart… I’m so glad it’s working for you too!
It is too soon to decide one way or the other. But if it works then keep on this schedule. I wanted to go on this but it wasn't available back a few years ago.
I am sure it will work. They start us off the highest dose to see what we can tolerate but it seems most of these medicines work at the lower dose. I say most. I don't know that they all do. I know Tamoxifen has been tested and works just as well at 5 mgs. as at 20mgs. Who would have thought.
Hi! 5/2 schedule is 5 days on and two days off…so over a period of 28 days you end up taking 20 pills…so I took pills Monday through Friday for Four weeks and took the weekends off. I got tested on the next Monday to see if I could restart the next cycle. There is no recovery week needed if things go as planned. Search through the posts for Alternative Dosing or 5/2 schedule…this topic has been around for about three years but just recently the trials were completed on this kind of dosing schedule. 🙏
Thank you so much for sharing this information. I am glad you are doing well on this new schedule and hope that continues to be the case. I have never thought that Ibrance was a one size fits all and that everyone should be on 125 mg or that everyone should take it for 21 days on and 7 days off. Everyone's body size and metabolism are so different and people have different tolerances for medications. Those parameters may be the ones stated in the standard of care based on clinical trials, etc. but should be able to be tweaked for individual patients. I'm glad that your determination was able to get you what you wanted and that it is working. Sending you some hugs and prayers for continued success.
Thanks so much for sharing this! Wonderful to hear you're not experiencing the crazy swings of the 3 weeks on/1 week off schedule. Please keep us informed going forward.
As I get further into the Ibrance/letrozole journey, I am beginning to feel more fatigue than ever and my neutrophils are starting to be consistently .8 or .9 after my week off. This schedule intrigues me and I'm going to discuss it with my oncologist when I see him. I do have a question - how does this affect your Ibrance prescription? Do you just get your regular monthly pack or do they give you capsules in a pill bottle?
Hello! Yes, it was the spiraling fatigue that made me speak up….as you must have realized, I always have one pill left over from the 21 pill blister pack ( it’s actually three packs of 7 pills in blister packaging). I just save them and will use them ultimately. There really is no change in the prescription because there is no recovery week and I just order my pills the same way to make sure I have a new pack for day 1 of the next 28 day schedule. Do ask you Onc about this schedule if the low neutrophils are wearing you down. 🙏🥰
Hi Susan! If your neutrophils are consistently below 1.0 I’m surprise that an adjustment in your meds hasn’t been made. My Onc told me that is the cutoff. Are you on 125mgs? Lin
I've been on 100mg for over 5 years. My former oncologist (who quit the medical field 😭) would never have given the go ahead on .8 - she was adamant about 1.0- but my new doc is fine with it. I'm starting to believe the side effects might be cummulative therefore the fatigue is greater than before. Maybe trying a new routine would help, but I would consider lowering the dosage.
dear Aquadog…I’m sorry to hear you are struggling with low neutrophils…it’s physically difficult but more importantly it leaves you vulnerable to infections…of any kind. Do consider a different schedule so that your body is not stressed to such dangerous levels..my ONC preferred to try this 5/2 schedule rather than lowering the dosage. It’s a step to consider if low neutrophils are a concern…and your right, the effects are cumulative. If you don’t recover during the recovery week, yiu are just further and further depleted. Take care!
I started in 125 with the 21/7 schedule and had some problems (low neutrophils and thrush), so went on 100 then 75. . I also talked onc into letting me go on a 5/2 schedule. Never took any kind of recovery week, just 5/2 for like 3 years. Neutrophils were always good and no other awful side effects except losing my sense of taste. Unfortunately, the Ibrance stopped working so I'm on another drug, but worked great for the time I was on it. I've read often that it appears that if Ibrance works for you, it works regardless of dosage. I saved document I found I think on this site to that affect. It's long, but worth reading:
1. I just had an appointment with my oncologist yesterday-- she told me that a Pfizer
representative told her recently that post-marketing analysis of both the earlier clinical trials and actual
patient use (data to be released in the future) is showing that ANY dose is equally effective-- that if it
works, it works, regardless of the dose, and there doesn't seem to be any correlation with degree or
duration of response based on dose. There will be more sub-group analyses reported in the next year or so trying to determine if a particular sub-group of patients (lobular vs ductal, ER+only vs both ER and PR+, etc...) responds better than others....
So I wouldn't be concerned about lowering the dose- I am almost at the end of cycle 32--the last 28 of
them at 75 mg. So it hasn't affected the effectiveness for me...and I will continue at this dose at least until my next scans in January.
One other thing to consider is a recommendation from a research pharmacist I talked with when I was
having difficulty with the higher doses and low WBCs/ANC-- he said, based on his knowledge of cancer biology and where Ibrance works in the cell reproduction process, it is his recommendation to take a lower dose for more days in a row and also minimize the amount of time off the medication, than to take a higher dose for fewer days or having longer days-off intervals.
Hope that you find that you get less side effects from the lower dose. May you dance with NED for years to come! "
and
2. "My onc, who is a researcher and has a wonderful team of scientists-- including pharmacists-- to work with, typically has a threshold of 2 cycles in a row either needing dose interruption due to a day 14 or day one WBC less than 2.7 or an ANC less than 0.8-0.9, or "time off drug" prolongation longer than a week (barring extenuating circumstances like surgery or some such thing).
She and her pharmacist feel that due to the average 29-hour half-life, prolonging the time off beyond 7
days is not as optimal as keeping on a consistent dose, even if it is a lower dose....however, they also
believe that once you have titrated down to 75 mg, if you are still getting a good clinical response but also still having those low blood counts, then shifting the dosing schedule around is definitely worth trying. Her pharmacist colleague (Sam, a lovely man!) says "There is no magic in the number 7", so you don't necessarily have to move to taking an entire second week o?, nor do you need to keep on a 21-day "on" cycle....he is a strong advocate for being creative, so long as you keep a few principles in mind:
Based on where Ibrance works in the cell reproduction cycle (and likely this holds true for
ribociclib/Kisquli, since it shares very similar CDK4 and CDK6 activity--abemaciclib has a slight different action profile and we never discussed it since it was long before it came to marker that we had our discussions)
* the time "on" Ibrance should always be longer than the time "off" the drug, and the longer "on" interval with the shortest "off" interval is the better choice (so, for example, 14 days on and 4 days off is better than 17 days on and 7 days off)
* due to the onset, duration of action and half-life of the drug, he suggests at least 10 days "on" is best to get meaningful benefit
* 2 days on and 1 day off for 21 days (or the 30 days you would have medication for on that regimen, then take some days off if needed based on your labs) is a very sound approach; he would not suggest ever going beyond every-other-day dosing; and he would prefer someone try every 36 hour dosing before they tried every-other-day. Other schedules could include 3 days on and one off or 4 on and 1 off
Also, please also keep in mind that there is NO data that suggests that people on a higher dose get a
better (regression vs stable disease) or longer response than people at a lower dose, so I would not be too reluctant to lower the dose based on undesirable side effects (low blood counts as well as fatigue,
nausea, GI upset, mouth sores, etc). I know that I was very reluctant and unhappy when I had to go to
lower doses, but I certainly felt better and also was finally able to complete full cycles and start the next
one on time, which ultimately is the best thing for suppressing the cancer cells. And now that I am more than 30 months (32 cycles) on it, I know that it is true that lower doses can be equally effective.
In fact, my onc believes that the lower doses may be more beneficial in the long run due to the lighter effects on the bone marrow, liver, kidneys and thus will allow my body to be in the best shape possible to deal with the cancer and the cancer medications for a long time. She says that it is well known that about 1/3 of cancer related deaths are due to the ultimate effects of the medications and not to the extent or action of the cancer at the time of death...so she almost always shifts doses around when possible to find the minimal effective dose for each patient in order to minimize the collateral damage to the body and it's organs.
Bonus is that many of her patients seem to have fewer or less serious side effects that is seen at the
Gosh, thank you for that extensive and detailed response …especially the reports about the dosing data…you are so right…this is a marathon and I don’t want to wear out my body trying to kill a cancer …I guess I have to just live with it. I definitely will keep you guys updated as I go forward…also at my age I have to accept a natural depletion of strength and endurance …so hurting my healthy cells is not helpful in the long run. Thank you so much !
Oh wow, this topic is exactly what I'm going through right now. I've been on Ibrance 125mg for 17 cycles and have tolerated it quite well except that my WBC's and neutrophils recently took another dip. I have a video visit with my ONC to talk about dosing. I'm sure she is going to want me to switch to the 100mg dosage. Up until now the thought of that REALLY distressed me because I thought that "more the better" for dosing. Your response, along with the others, has given me hope that it could be a good thing to lower the dosage. Thank you!
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Update on failing Ibrance!
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