You are here

Is dose reduction possible on imatinib?

Categories:

Hello everyone!

I've recently read many posts and stories about people who have successfully reduced their dosage of dasatinib, and if I'm not mistaken there are several people here on this forum who are on 70mg, 50mg and even 20mg and maintaining excellent BCR-Abl results.  My CML is well controlled on 400mg imatinib, but as we all know it's not fun to endure the side effects of the TKIs and longer than is necessary, so I was hoping for some advice before I meet my doctor next week as I'm hoping to discuss dose reduction.

My BCR-Abl levels took quite long to reduce, and I only reached MMR after 24 months on dasatinib.  I developed a rare side effect of swollen lymph nodes and had to discontinue dasatinib, replacing it with imatinib, and my levels have reduced to around MR4 - MR4.5 - my last seven tests were as follows: 

Jul 2020: 0.011%

Nov 2020: 0.018%

Feb 2021: 0.004%

Jun 2021: 0.013%

Oct 2021: 0.003%

Feb 2022: 0.009%

Jun 2022: 0.003%

I know there is quite some variation in these results but I interpret them as being nice and stable for two years now.  My question to the community at large is whether anyone has reduced their dosage of imatinib from 400mg to 300mg or less with any success and whether this is even possible?  My doctor has indicated on several occasions that I'm probably never going to be a candidate for TFR because of my slow response, high risk factor (11% blasts and an enormous spleen when diagnosed) and the fact that I've already changed from dasatinib, but I'd really like to try a dose reduction given that I struggle with side effects.

Thanks in advance and best wishes from a cold and wintery South Africa!

Martin

 

 

Hi Martin, simple answer is yes.

There a long thread on this here

In summary after many years on 400mg imatinib, I reduced to 200mg for year and maintained MMR. I stopped taking the pills and was in TFR for 17 months when BCRABL went above 0.1%. I started again on 400mg, and stayed for a year. I regained MMR in 3 months. After a year (9 months ago) I reduced to 200mg again and am still undetectable. The improvement in side effects was greater in the reduction from 400mg to 200mg than the change from 200mg to 0.

Hope that is useful

Hello Alistair

Thank you so much for the thread and for the detailed information - I'm thrilled to hear that it is possible and read your experience with interest.

Unfortunately, though, it doesn't seem on the cards for me to reduce my dosage just yet.  My doctor is still worried about my high risk CML and also about the fact that my tests bounce in and out of MR4... so she wants to give it a few years yet before considering a dose reduction.  

But thank you so much for sharing this information!

All the best

Martin

Hi Martin,

I was able to reduce my imatinib dose from 600 to 400. Here are my stats roughly:

Diagnosis: 2014
Starting dose: 400 but increased to 600 due to insufficient response
Date of dose reduction: 2019
BRC-ABL before dose reduction: Log 4.5

What did doctors say about dose reduction?

Around 2017, I asked about the possibility of lowering my dose after a sequence of low BCR-ABL results. The first doctor said no (I still consult with this one). The second said no because all those who attempted dose reduction had the disease come back. The third doctor wanted me to switch to Nilotinib and said the switch would be permanent.

I kept taking 600 Imatinib, and decided to improved my well-being, hoping to keep my BCR-ABL results low to take another shot at applying for a dose reduction again. However, around 2019, my doctor said the government was having a problem in the supply chain which would make Imatinib unavailable for a few months. It was my opportunity to test what my response would be by taking a lesser dose, so I purchased 400mg tablets. After three months on 400mg, my BRC-ABL test came back as log 4.5 and has been like that since then.

Important take-aways:
* Dose reduction is possible.
* We trust too much in the supply chain.
* Doctors have different opinions.
* Imatinib is expensive

I will eventually try lowering my dose again, but that is not a priority. I'm busy with other things, including working and having a good time with my family. Please, don't tell anyone, but sometimes I forget to take my medicine and my BCR-ABL is still 4.5 :)

I was on 400mg imatinib for 11years straight with slow but steady decline but I never achieved CMR. Then it just stopped working. I think dose reduction is possible and preferable especially if it works. The issue really is about cost. Here is the states PCR tests are pricey and insurance companies can balk at frequent testing but frequent testing is really the only way to attempt reduction safely. If the numbers rise then go back to a dose that works as fast as possible.

Hi there

I have been on imatinib since diagnosis in Sept 2009. In 2017 I dropped to 300mgs dose and found after about 9 months my results dropped down to MR4.5/MR5 and a couple were even 0.0000%. Interesting that while on the DESTINY trial in 2014/15 which involved dropping to half dose ( 200mgs imatinib) for 13 months before stopping, I lost MMR at Month 12 and went up to 0.5%. Back to 400mgs for a while, regained MMR fast and then I tried 200mgs again later but abandoned it when my levels rose to 0.05% . Yes still in MMR but the trend was moving upwards and I didn't want to go back onto the full dose. So since 2017 I am happily on 300mgs which seems to be the optimal dose for me. I believe we all have an optimal dose - for some lucky ones this can be treatment free but for others not.

I guess my point is that MMR is regained after a rise in most cases after a reduction.

Good luck

Chrissie

Hi Israel

Thank you so much for sharing your story and for the detailed information! Very glad you're able to maintain MMR on 400mg, and also interesting that you first increased the dose to 600mg because of poor response.  And your four take-aways are spot on : I think it's really important to advocate for ourselves and to get a second opinion if possible.  So the supply chain story turned out to be a blessing in disguise, I guess - here, my imatinib gets delivered every month and I have an oversupply (enough for around 6 months now).  But the cost factor is a huge incentive to try for a dose reduction someday.

All the best from South Africa

Martin

Hi Pojo

Thanks for the information - that's also something I worry about - that imatinib somehow stops working after a while.  The point about frequent testing is really important, and I hadn't thought of the costs of extra tests compared to an extra month of imatinib.  Here, the test costs about 60% of the cost of a month's supply of imatinib.  There is so much to consider with the CML and once things have stabilised. it's just tempting to leave them as they are until something changes.  At the same time I haven't given up hope of eventually stopping this daily bullet!

Best wishes

Martin

 

Hi Chrissie

Thanks for your response - I had actually forgotten about the fact that people halved their doses in DESTINY trial for a year first.  I think I'll go and read up on the statistics before trying to convince my doctor to let me try, but it will probably rise again since I got off to a slow start on imatinib.  Interesting that 300mg seems to work well for you.

I'm so grateful for these stories as they give me something to consider and work with before seeing my doctor again!

All the best from South Africa

Martin