A Treatment-free Interval Allowed by Ponatinib as Fourth-line Therapy.

Background: The third-generation tyrosine kinase inhibitor ponatinib has demonstrated high clinical efficacy in the setting of patients with resistant chronic phase chronic myeloid leukemia (CML), also inducing deep molecular responses. However, ponatinib-related cardiovascular toxicities make management challenging, especially of those patients with CML with previous cardiovascular comorbidities. Case Report: We report on the efficacy of ponatinib treatment used as fourth-line therapy in a 55-year-old woman affected by significant comorbidities (mainly cardiovascular) present before the diagnosis of CML. Ponatinib therapy induced a rapid and excellent clinical response, with the achievement of a durable deep molecular response that allowed us to propose a strategy of treatment discontinuation in order to reduce drug-related toxicities. Conclusion: A strategy of a treatment-free interval might represent a useful clinical tool in those patients with CML who achieve a durable deep molecular response but are also affected by significant comorbidities in order to minimize the risk of ponatinib-related toxicities.