Guest article by Cheryl-Anne Simoneau, Co-Founder & President, CML Society of Canada
CML is one of the great success stories of modern oncology. Tyrosine kinase inhibitors (TKIs) transformed a once-fatal diagnosis into a manageable chronic condition — for many patients, even an opportunity to eventually attempt treatment-free remission (TFR). But between that remarkable possibility and the daily reality of living on TKI therapy, there is a gap that doesn’t get talked about enough: the cumulative, compounding burden of side effects.
Most TKIs work by competing with ATP at the BCR::ABL1 binding site. Because the ATP-binding pocket is structurally similar across hundreds of kinases in the body, these drugs don’t act on CML cells alone — they interfere with normal cellular signalling in healthy tissues as well.¹ The result is a constellation of side effects that many patients know intimately: persistent fatigue, joint pain, muscle cramps, nausea, and digestive disruption. Not as rare events. As daily companions.²
Fatigue, in particular, is among the most commonly reported quality-of-life concerns for people on TKI therapy. It is not the fatigue of a bad night’s sleep. It is the kind that settles into the body over months and years, quietly reshaping what feels possible — what you attempt, what you cancel, what you push through, and at what cost.³
And this is where the clinical stakes become very real.
When side effects are severe or unrelenting, patients may reduce their dose, skip doses, or stop altogether — often without telling their care team. The consequences are not abstract. Missing treatment milestones, like major molecular response at twelve months, can delay or eliminate a patient’s path toward TFR. The window matters. The trajectory matters.
What makes this even more complex is that switching to a newer TKI does not reset the clock on a patient’s physical experience. The body does not restart. Years of fatigue, joint inflammation, and gastrointestinal strain do not simply resolve because the prescription changes. These effects accumulate and carry forward, even as the molecular target shifts.⁴ Meanwhile, the hematologists and CML specialists who might help patients navigate these challenges are stretched. Appointment time is limited. Side effect management often falls through the cracks — and patients, looking for relief, turn to sources that may not understand the delicate balance of CML treatment goals.
This is precisely why specialized fatigue support — knowledgeable, oncology-informed, and built around what CML patients are actually experiencing — is not a luxury. It is part of the treatment itself.
At Cancer Fatigue Services, that is exactly what you offer. And for patients trying to stay the course toward remission, that support may make all the difference.
Notes
- Prabhu S, et al. “Tyrosine Kinase Inhibitors in Leukemia and Cardiovascular Events.” PMC / American Heart Association. 2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC6993877/
- Richter J, et al. “Skeletal Muscle Toxicity Associated with Tyrosine Kinase Inhibitor Therapy in Patients with Chronic Myeloid Leukemia.” Leukemia / PMC. 2019. https://pmc.ncbi.nlm.nih.gov/articles/PMC6756217/
- Hobbs G. “What’s New in CML Treatment: TKIs, Asciminib, and Long-Term Care.” Patient Power. 2026. https://www.patientpower.info/video/chronic-myelogenous-leukemia/whats-new-in-cml-treatment-tkis-asciminib-and-long-term-care
- Shanmuganathan N, et al. “Exploring Treatment Decision-Making in Chronic Myeloid Leukemia in Chronic Phase.” Frontiers in Oncology. 2024. https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2024.1369246/full
