Ribocyclib dose

[Stefftrees]

Hi there everyone,

Thanks for the support, warmth and information of this platform.

It is a really special community.

My mother is managing metastatic breast cancer. She was diagnosed this January and had to have a spinal fusion ( spreading there ) to her bone and liver.

She is currently on a combination of Ribocyclib with fuvestrant. She is doing very well, with positive signs in her liver and tumour markers.

She is on the full dosage of Ribo - 3 tablets.

We are working with an integrative oncologist also, who has helped a great deal in providing a holistic support to her body in supplements and diet.

My mum's white blood cells take a real knock during Ribo. The doctors seem happy with her neutrophil count, at 1.1 but my Mum is keen to drop to 2 tablets. She had to pause for one week a month ago because they were so low. The increased to 2.6 when she was off Ribo and now, back on Ribo her neutrophils have dropped to 1.1.

Has anyone had the experience of dropping from 3 Ribo tablets to 2 Ribo tablets due to neutrophil counts?

Any experience / info would shed a light for us,

Thank you and warmth to all,

Stephanie x

[Hazelgreen]

Hi Stephanie,

I have been on 600 mg ribociclib since February 2022 (27 months). For the first 9 months, I took it on the usual 3 weeks on/ 1 week off schedule, but then found I needed to take 2 weeks off in order to get my neutrophils above 1.0.

After I started a 5 days on /2 days off schedule 16 months ago, my neutrophils stayed above 1.6, and my cancer markers remained in the normal range (0-30). This made sense to me because I was giving my body a chance to recover from the ribociclib for 2 days every week, rather than waiting for 1 week after 3 weeks on.

Research has found that the 5 days on /2 days off schedule works well for Ibrance so I suspect the same will be true for Kisqali but, so far, I haven't found a study that proves this to be the case. However, in a 28 day period, the choice is only between 20 or 21 days of the hormone while the spacing of the drug is either 5 days on or 21 days on.

I hope your mother's experience may be similar to mine. I find it easy to stay on a regular schedule by taking 600 mg. of Kisqali on week days, and none on the weekends.

Best of luck,

Cindy

[Stefftrees in reply to Hazelgreen]

Hi Cindy,

This is really helpful. Thank you for taking the time to share your story and experience.

I am so glad to hear about your nutophils and markers improving.

Can I clarify, you take Ribbo 5 days in a row, with two days off at weekend, for 21 days and then take a full week off before you begin again? Or are you 5 days in a row, with two off consistently without a break? I am pleased to hear there are different rhythms you can work with.

warm wishes,

Stephanie

[Hazelgreen in reply to Stefftrees]

Hi Stephanie,

I take ribociclib (Kisqali is the trade name) and letrozole every weekday with none on the weekends continuously without any other break.

I don't know whether age is relevant, but I am 78 years old, and also take heart medication. Unfortunately, few medical research studies mention age.

Cheers, Cindy

[TammyCross]

I think Cindy's response is more relevant to your mother's situation, but I have been on 400 mg ribociclib since I started -- not because of low neutrophils, but because it can cause a problem with heart rhythm (prolonged QTc, and mine is already on the long side). I know with Ibrance that they have found the lower dose is just as effective. I didn't think they had looked at it for ribo, but at the recent LBCC conference, one of the presenters said it was true of all the CDK4/6 inhibitors -- that the lower doses are just as effective.

Your mother should ask her onc about lowering the dose, too, but I think that is the state of knowledge now. Not enough research on the lowest effective dose. Instead, all the research is on the maximum tolerated dose.

[Hazelgreen in reply to TammyCross]

Hi Tammy,

If 400 mg works as well as 600 mg, would 200 mg also work?

Thanks for an interesting discussion. I'll check for research findings...

Cheers, Cindy

[TammyCross in reply to Hazelgreen]

Maybe! Who knows? On the one hand, I want to put the least toxic treatments in my body; on the other, I want to knock down the cancer, so bring it. Very confusing. Hope you find something on it.

[Hazelgreen in reply to TammyCross]

So far, I've not found a study that directly compares results with various dosages of a cancer drug. Drug companies may prefer not to know that lower dosages are as effective as higher dosages given this might lower their profit margins. I believe drug research is largely funded by drug companies, not cancer agencies.

[Stefftrees in reply to TammyCross]

Thank you for this Tammy. That's really interesting to know about the research focused on maximum dose.

[Pimpelmees]

Hello to all! I hope to be able to contribute to this dicussion. I'm on 600 ribociclib + letrozole from 6 March this year. Neutrofyls dropped dramatically the first cycle from 5.0 to 1.2. I investigated and found a clinical essay on RE+ bc chemotherapy and Uncaria tomentosa with positive results on neutrofyls. I used Ut 3gr three times a day with boiling water and after 2 weeks they rose to 2.8 and another 2 weeks later they are now at 3.6. Commented it with my onco and she confirmed there's no interference with ribociclib. Unfortunately I am at a hold now because of bad liver values. Working on that. Any ideas? Suppose I can continue this Friday. Love to all and English isn't my first language, so sorry for that.

[Stefftrees in reply to Pimpelmees]

Thank you for your message and info. I am glad to hear that cat's claw is helping you. 3.6 is wonderful. The plants are our allies!I will look into this for my mum. She has been taking astragalus to support her white blood cells. Still to fully measure the overall affect this is having, with more time passing I'm sure we'll have more clarity.

In light of the liver - my mum has been taking milk thistle everyday ( she can manage one tablet of 150mg) and drinking a glass of celery juice 3 times a week. Her liver seems to have reached a normal state. These may well have helped her. Her integrative oncologist recommended these.

warmth,

Stephanie

[Corrina97]

I had to reduce from.600mg to 400mg partly because of low neutrophils and still on the same drug after nearly 4 years. We are all different and some of us just can't tolerate 600mg and find that 400mg works fine for us x

[Stefftrees]

I really appreciate everyone's responses. It is so valuable to hear everyone's individual stories.

I have a further question regarding side affects. My mother says she feels really quite tired with the 3 tablets but the oncologists have said there are no side affects which we found strange - surely when your neutrophils take a dip, there are side affects the body feels?

I wonder if anyone has experienced fatigue as a symptom of low neutrophil count?

Thank you so much,

sending warmth,

Stephanie