Abemaciclib along Letrozole

Has anyone had abemaciclib together with letrozole? My oncolgist wants to put me on this for 2 years as my primary BC was very advanced, big tumor 12.5cm and 3 lymph nodes affected. I had mastectomy and 31 lymph nodes removed plus 5 months of gruelling chemo and 15 RT session and will be on AI (letrozole) for 7 years. This is a new drug recently approved so I am just wondering if anybody has the same combination of drugs and if yes, what kind of side effects to expect. Thanks

Hi , I’m not on this but my sister in law is for the same reasons as yourself. She has had problems with diarrhoea and her immune system has been very low at times, she is very prone to infections and has had the dose reduced a bit to cope with it . She does get tired at times but she is keeping fit going to the gym etc and that helps.

Good luck xx

Similar to you my primary BC was advanced and multiple lymph nodes were affected. I have been taking Abemaciclib and Letrozole for about 4 weeks now. The list of potential side effects is quite daunting but so far the main noticeable side effect is diarrhoea, which for me is controlled by Loperamide (Imodium). I am having blood tests every fortnight at the moment, test after 4 weeks showed that my white blood cell count had reduced, so I was advised to be aware that I have a higher infection risk. If the WBC count gets too low, the plan would be to come off the Abemaciclib for a short time to let this recover and then restart. 

So reassuring to read these comments.  I finished chemo in June. Im now halfway through radiotherapy.  Just been offered abemaciclib. Really struggling with decision as to whether I take it or not. 

After reading this thread I think I should take it and at least give it a try .How is everyone getting on with hair loss? I have just regrown about 2 cms of my hair . In the notes I was given it states that hair loss is pretty much a certainly

I didnt get any vomiting or diarrhoea when I had chemo so hope it won’t be too bad with abemaciclib

Thank you for this thread. I’ve been very stressed but feel relieved I have found other people in the same position

Hi mun4o I am in the process of deciding whether or not to take abemaciclib and have tried to access the Lancet article that raises questions of its use for early breast cancer. I have not been able to access any info on it at all…please can you explain how you did this? Many thanks, 


Hi caroleanne,

I did it through my work but you have to pay if you don’t have access to web of science, etc.

I can tell you that from my own experience (I started Abemaciclib last June) and the article wasn’t out and it was still not prescribed on the NHS…I made up my mind when my oncologist said that with my type of cancer the chances of recurrence are really high in the first two years after finishing treatment…so yeah you have to weigh the pros and cons…

Sir Paul Nurse found out these proteins and got a Nobel prize in 2000…20 years later this miracle drug saves lives!!! No matter how awful are the side effects (I am on the lowest dose of 50mg) it still works…just to clarify that I am not working for or getting paid by Eli Lilly!!!

Hope that you can make the right choice…


Hi everyone 

I’ve been on 100mg for 6 months now. Agree that my nails aren’t growing.  My hair seems to be doing ok. My energy levels are up and down but making the most of it when I’m feeling good. I’m struggling emotionally as it seems to be a constant round of appointments which prevents me from doing ’nice things’

Starting counselling in August.  

Seem to be constantly having blood tests as levels are low and now I’ve missed the deadline for the covid jab . Not sure if I’ll still be able to get it anywhere!

On the positive side I do still feel its important to carry on with this drug. 

I find this forum really helpful.  I agree that people think you’re ’ok’ when you’re hair grows back. 

Take care everyone ?

Hello @caroleanne @my oncologist told me that (back when I started it in July last year) that it was said to be more effective than chemo regarding reducing the risk of recurrence.

It is early days. They could see the benefit after 2 years and I think I read that they continued to see a benefit when they checked again after 4 years.

I have got off relatively lightly. I’m more tired on it and take diarrhoea relief at the first signs of trouble (slightly looser bowels / more frequent bowel movements) but for me I have had very few extreme cases of diarrhoea considering I’m approaching a year now.

I asked my oncologist if it’s still effective on a lower dose and he said yes as some of the people on the study will have started on the higher dose then had to reduce yet they still saw benefit.

when I asked him if it’s common to reduce the dose he just smiled and said yes in a very confident way.

so, I’d personally suggest trying it, being prepared to reduce the dose if you run into issues and don’t give yourself a hard time if you have to have breaks / reduce the dose or even stop depending on how you and your body copes with it.

@Wendy E 

I wonder if you would mind updating me on your abemaciclib effects?

my oncologist tells me the effects increase each cycle but I wondered if there is a point it evens out, eg 4 months, six months etc?

I had diarrhoea every 6 days or so first cycle, every 3 second cycle, now most days third cycle. Loperamide helps and I’m now up to 2 as required so still got a way to go. From your experience, will it keep increasing or eventually settle?

I see lots of people talk about fatigue in afternoon… if I wake up myself in the morning I’m okay but if I wake because of alarm for work, I am so groggy, headache, exhausted (even if 10 hrs sleep). After about two hours I come too and feel better. Does this sound like anything anyone else experiences?


Hi @LauraR 

Yes, from my experience that sounds exactly how I felt…I started on 150mg…then reduced the dose to 100mg and now am on 50mg…I also had regular breaks but not on the lower dose though…

My oncologist said that because is for prevention is okay to be on the lower dose as it still works…to be honest the fatigue and the diarrhoea were the same on the 150mg and on the 100mg…I was taking 9 loperamides (max dose) and was a prisoner at home…it was horrendous I am not going to lie and never settled or even out… never… I was taking it for an year and had a choice to go on the 50mg or stop it…I decided to persist!!

Now on the 50mg is much better I still have the occasional incident but the energy levels are much better…and my oncologist said that is definitely better to be on the lower dose that stop it altogether.

Take care and all the best.

Many thanks for your comment Susie59. We’re really glad you’re finding the forum useful ?

Hi @Rachel_123 thankyou so much for your detailed reply. I had a grade 3 2.5cm er+ tumour removed last November, along with 36 lymph nodes two of which were diseased, so high recurrence risk; also LVI present. I had six rounds of EC-T chemo, the docetaxel part at 80% because of side effects and five days in hospital. I feel this dosage reduction will have negatively affected my recurrence risk too.

I have been taking letrozole for 4 weeks, frequent but mild hot flushes being the only side effect so far. It came as a complete shock to me to be offered abemaciclib after my radiotherapy finished two weeks ago. I had not heard of the drug before and rather than be pleased and positive about being eligible for it, I had soon found and  read just about every negative comment on the internet and was terrified…hence my post and the need to find reasons to decline it!

Thankfully I am now feeling more positive although still nervous of the long list of side effects. I had not realised that abemaciclib may be as effective as chemo regarding recurrence and this information has been a great boost.

My oncologist is keen for me to have this treatment and has offered to start me at the lowest dose, increasing if at all possible rather than starting high and then reducing if necessary.  I feel fortunate my onco is prepared to give me this option and have decided to go ahead, hopefully getting at least to the middle dose. I am reassured though by what you have said about even the lowest dose being effective. 

Warmest good wishes to you and all the best in the second year of this treatment x

Ho @mun4o , thanks for your reply, really helpful. I have decided to go with the treatment…my oncologist has been really accommodating about my fears of side effects and has given me the option of beginning on the lowest dose and working up if possible. 

My post to you was my first on the forum and I haven’t quite found my way round. I have just replied to another response I got to my question and thought I had included you but it seems not. Sorry about that…it gives a bit of background info if you are like me and read whole threads. If not, no worries ?

Best wishes on the remainder of your treatment,  I can see from your posts you have struggled to reach your present manageable position and your perseverance is inspiring. I would send you one of those heart hugs but haven’t worked out how yet!..take care?

Hi @caroleanne,

No worries I always read the whole treads. I actually started this tread last year as there were not that many women taking the Abemaciclib for early BC…and was at a loss what to do exactly like you…

Mine was lobular grade 2 stage 3 ER8 PR8 positive and the tumor was very big 12.5cm. I had 34 lymph nodes removed - 3 positive. So yeah I was also surprised when after having 5 months of chemo (I had 4 EC cycles and 12 Paclitaxel cycles) and 15 RT sessions my oncologist told me that I need to start the Abemaciclib. I’ve still got a year to go…

It’s been hell for me but from the messages here on this forum some ladies are tolerating it better so fingers crossed you are going to be one of them and especially, that you are starting on the lower dose it will be okay I hope…

It sounds like you’ve got a great oncologist!! That’s very important…

Take care and all the best.

P.S. If you want to message me on the private chat your email address I can send you the article…

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@LauraR Firstly aplogies for not answering sooner, work has been busy and then it has been school holidays.

Let me start off by saying I have been fortunate in how well I coped with chemo, radio and now the abemaciclib and I know that many others on here have not been as fortunate. I am back a work full time, but being careful not to take on too much and have mostly restarted my leisure activites (pilates has help my lymphaeodema, balance and general wellbeing). My energy levels are still much lower than before I started treatment but are much improved from the low point during chemo.

I have been on abemaciclib (2 x 150mg) and letrozole for about 16 months and haven’t need to reduce dosage or have breaks from the drug. The main side effect is still diarrhoea but I find that 1-2 Loperamide keeps that under control, without the Loperamide the diarrhoea would be daily. This hasn’t noticably got worse over time but I have got better at managing it.

More recently i have had other symptoms that I think may be attributable to the abemaciclib - watering eyes, small muscle twitching in the lips.

The eye watering happened in spring around about the same time as I get hayfever but has since more or less stopped. I also got more tired and breathless at about the same time, so I wonder if the slight hayfever was enough to allow other symptoms to appear/worsen. Once I got past my hayfever the tiredness etc came back to my normal levels.

The muscle twitching in the lips feels like a small quiver and when I press my lips together more firmly it stops, I think it happens more when I am tired.

I have noticed that my nails are softer and split more easily as well as I think this has got worse over time, but equally it could be that as I am doing more the nails get damaged more.

Best Wishes


Continuing the discussion from Abemaciclib along Letrozole:

After a tough 2023 having a masectomy, months of chemo and 15 x radiotherapy, i am now due to start abemaciclib and letrozole and am really worried about the list of possible side effects. No one i speak to at the hospital seem to understand my concerns and i’m trying to get my head around facing being ill on these tablets for years , when i’d just started to feel normal again ,my hair is starting to grow back and i was looking forward to
seeing friends and having a life again.
Did you all lose hair , how helpful were your oncologists about giving lower doses. Thanks for any advise .


I can totally relate to your apprehension, the side effect list for the abemaciclib is so grim! I was not looking forward to starting this drug and, even though it all looked really grim on paper, I did underestimate the impact it would have on me. My main side effects were diarrhoea which was treated successfully with prescribed imodium, and awful fatigue and lack of energy. My neutrophil level dropped a few times so that I was neutropenic, but even then the oncologist didn’t reduce my dose, I had to request the dose reduction. It was reduced after my request though, so if you fnd yourself struggling, do make the request.
I have been better on 100mg, though still very fatigued and occasional bouts of diarrhoea. Thankfully I do not work at a job but if I did I think I would be requesting a further reduction. For now I’m ok with on 100mg.
Proof has been published that the effectiveness of abemaciclib relies on the regularity of taking it twice daily, 12 hours apart, as opposed to how high the dose is, so do not despair if you do find that you need the reduction. The announcement about this finding was presented by the drug manufacturer at the ESMO conference on 6 October 2023, which you can Google to read details if you are interested.
Thankfully I have not lost any hair so far, but I think the growth rate has slowed down since beginning on this drug. It was growing back quite well after the chemo, if at different rates in different areas of my head, and much darker than it used to be! But I wasn’t losing any hair at all like you do normally on a daily basis and that has continued through my abemaciclib use. I think it may just be starting to fall now in the natural way, but it has been nearly a year since I finished chemo so that is expected.
I must say my nails have been effected. They are very prone to soreness, splitting, bending and breaking, but I just make sure to keep the short and use intensive hand and nail moisturiser. It is tolerable and manageable.
There is another thread on here about abemaciclib, it is titled ‘Feeling miserable and depressed’ which I’m sure does not fill you with confidence, but it isn’t all bad and it is handy to read about the different side effects people have experienced. There is just no telling how you individually will react but how ever bad it is, there are ways and means of managing the worst effects. I honestly believe that it is worth it for the chance of preventing this dreadful cancer from coming back.
It is utterly gross that we must endure all this because of such a horrible disease, but you will get through, having already gone through everything you have faced. All the very best :hugs:

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Continuing the discussion from [Abemaciclib along Letrozole](https://forum.breastcancern
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Thank you so much for that reply Beck. I’m glad you are managing ok. I’m just so worried that i’ll get all the worse side effects. I relise we’re lucky treatments are available, but i can’t see an end to it all right now. I was starting to feel positive after the big treatments finished and my hair and eyelashes started sprouting back and i thought i could face normal things again. So depressing and they wont even tell me how long i’ll be on these tablets. When i ask questions the answers are very vague. Theres no support groups near me , so this forum is helpful.
Wishing you all well on your journeys xx