Asciminib may be a promising treatment option for intolerance of tyrosine kinase inhibitors (TKIs). It is a first-in-class inhibitor with a more selective mechanism of action different from the ATP-competitive inhibition that occurs with TKIs. Adverse effects (AEs) related to the inhibition of non-BCR::ABL1 kinases have been expected to be greatly diminished

According to the literature, fifty-five percent of patients experienced some AEs: mostly mild (grades 1–2), with 18% being grade 3–4. The most frequent AEs were fatigue (18%), skin rash (18%) thrombocytopenia (17%), and anemia (12%). The most frequent grade 3–4 AEs were thrombopenia (3.9%) and fatigue (3%). Other AEs were pneumonitis and hypoglycemia reported post-marketingly.

A 61-year-old man was diagnosed with chronic myeloid leukemia (CML) and started on 80 mg asciminib. After 20 weeks of treatment, he experienced an unexpected change in hair color from gray to dark brown, without using hair dye or supplements. The same color change was also present in his mustache and beard. No other side effects were observed

It was decided to monitor the patient with no action taken as he feel pleasant with this unexpected side effect of asciminib. CMl remained in deep molecular remission. The dark brown hair color persisted over time.

Hair hyperpigmentation likely occurred through melanocyte activation via asciminib. Severe side effects may require dosage adjustments, while milder effects can be monitored closely. The newly observed hair color restoration in this case highlights potential dual (therapeutic and aesthetic) applications of this class of agents.