Bosutinib-Induced Stevens-Johnson Syndrome and Evidence of Tolerance to a Structurally Dissimilar Tyrosine Kinase Inhibitor

Abstract

Bosutinib is a breakpoint cluster region-Abelson gene (BCR-ABL) tyrosine kinase inhibitor (TKI) used for the treatment of chronic myeloid leukemia (CML). Patients on TKIs may develop severe cutaneous adverse reactions (SCARs). A 73-year-old female with CML treated with a second-generation TKI (bosutinib) was evaluated after developing fever and a maculopapular exanthema with skin-peeling affecting her lips, oral mucosa, and genitals 10 days after starting the medication. She required hospitalization, bosutinib discontinuation, and management with intravenous corticosteroids and antibiotics. Patch testing was contraindicated due to the severity of the reaction. The patient was subsequently challenged with first-generation TKI along with careful observation without any adverse reactions. She has not reported any adverse reactions while on therapy in the last two years. In patients who have suffered from SCARs, the suspected triggers must be avoided in all instances. In some cases, the underlying condition limits the use of alternative agents, but low-concentration patch testing may help guide alternative therapies within the same medication group. There appears to be a low cross-reactivity among generational TKIs, and our patient benefited from treatment with a structurally dissimilar alternative TKI for her CML.