Safety and Efficacy of Ponatinib for the Treatment of Recurrent or Refractory Pediatric Leukemias, Lymphomas, or Solid Tumors

Leukemias, lymphomas, and solid tumors are different types of cancer characterized by the uncontrolled growth of tumor cells. Leukemias originate in the hematopoietic system, while lymphomas originate in cells of the lymphatic system, which is also a subset of the hematopoietic system. Solid tumors affect solid organs or tissues. The causes are often not fully understood, but genetic factors and environmental factors play a role. Symptoms vary from disease to disease. Initial treatment depends on the type of disease, the patient’s age, and their physical condition. However, if these standard therapies are ineffective or the disease recurs, there are often no established follow-up treatment options for children.

Ponatinib is a so-called tyrosine kinase inhibitor (TKI) that blocks certain proteins (tyrosine kinases) that promote the growth and proliferation of cancer cells. The drug is already approved for the treatment of chronic myeloid leukemia (CML) and certain forms of acute lymphoblastic leukemia (Ph+ ALL) in adults.

The goal of this Phase 1/2 study is to test ponatinib in children and adolescents with various relapsed or refractory cancers. The study is divided into two phases: In Phase 1 (dose-finding), the optimal dose of ponatinib will be determined by administering different doses to various participants. The choice of dose will also depend on the patients’ age. Subsequently, in Phase 2 (dose expansion), the safety, tolerability, pharmacokinetics (how the body absorbs, distributes, metabolizes, and excretes the drug), and efficacy of this dose will be investigated in a larger group of patients. There is no random assignment to different groups, and the study is open-label, meaning that medical staff and patients (or their parents) know which medication is being administered. The study will last for up to approximately 1.5 years, during which the efficacy of the therapy and the occurrence of side effects caused by the medication will be evaluated. A key factor is whether or when the disease recurs during treatment. The primary endpoint in Phase 1 of the study is the occurrence of dose-limiting side effects within 4 weeks; in Phase 2, it is the response rate to therapy.

Patients between the ages of 1 and 17 with leukemia, lymphoma, or a solid tumor are eligible to participate in the study. The disease must have been previously treated and must either be uncontrollable (refractory) or have recurred. The exact eligibility criteria vary significantly depending on the type of tumor and must be evaluated in detail as a prerequisite for study participation.