Ponatinib Plus Reduced-intensity Chemotherapy in the First-line Treatment of Adult Patients With Ph+ ALL

This is a phase II interventional trial to evaluate the efficacy of ponatinib plus reduced-intensity chemotherapy in the first-line treatment of adult patients with Ph+ acute lymphoblastic leukemia. This combination has the potential to improve the depth of molecular responses after the induction phase of treatment. Patients who achieve a complete molecular response (CMR) at week 11 will not be directed to alloSCT and will receive consolidation chemotherapy combined with ponatinib, followed by 24 months of ponatinib maintenance. The aim is to spare individuals with a low probability of relapse from overtreatment with more intensive and toxic transplant procedure.

Primary Objective:

To evaluate the percentage of complete molecular responses (CMR) after two cycles of remission induction therapy composed of two cycles of chemotherapy plus ponatinib. CMR is defined as BCR-ABL1 below the Limit of Quantification by Droplet Digital Polymerase Chain Reaction (ddPCR).

Outline:

Pre-phase:

dexamethasone 10 mg/m2 PO (day -5 till -1), cyclophosphamide IV 200 mg/m2 (day -3 till -1), methotrexate 15 mg IT.

Induction I:

ponatinib 30 mg/day PO once daily (QD) continuously since day 1, rituximab 375 mg/m2 IV (day 1), dexamethasone 10 mg/m2 PO (day 1-2, 8-11), vincristine 2 mg IV (day 1, 8, 15), Granulocyte-Colony Stimulating Factor (G-CSF) until recovery.

Induction II:

ponatinib 30 mg/day PO QD continuously, rituximab 375 mg/m2 IV (day 23), cyclophosphamide 1000 mg/m2 IV (day 24), cytarabine 75 mg/m2 IV (day 26-29, 33-36), Granulocyte StimuG-CSF until recovery, methotrexate 15 mg IT (day 26, 33) methotrexate 15 mg + cytarabine 40 mg + dexamethasone 4 mg IT (day 40). Week 11: Primary endpoint assessment.

Consolidation I (week 12):

ponatinib 30 mg/day PO QD continuously, rituximab 375 mg/m2 IV (day 1), dexamethasone 10 mg/m2 PO (day 1-4), vindesine 3 mg/m2 IV (day 2), methotrexate 1.5 g/m2 IV (day 2), cytarabine 2x 2 g/m2 IV (day 5), G-CSF until recovery, methotrexate 15 mg + cytarabine 40 mg + dexamethasone 4 mg IT (day 8). Patients in complete molecular response at week 11 will be treated with 5 additional blocks of chemotherapy followed by maintenance therapy; patients with molecular failure at week 11 will end the study and be directed to alloSCT.

Consolidation II (week 18):

ponatinib 15 mg/day PO QD continuously, rituximab 375 mg/m2 IV (day 1), cyclophosphamide 500 mg/m2 IV (day 2,3), etoposide (VP-16) 75 mg/m2 IV (day 2,3), methotrexate 15 mg + cytarabine 40 mg + dexamethasone 4 mg IT (day 1).

Consolidation III+V (weeks 24 and 36):

ponatinib 15 mg/day PO QD continuously, rituximab 375 mg/m2 IV (day 1), methotrexate 1.5 g/m2 IV (day 2), vincristine 1 mg IV (day 2), 6-mercaptopurine 60 mg/m2 PO (day 2-8), methotrexate 15 mg + cytarabine 40 mg + dexamethasone 4 mg IT at day 1.

Consolidation IV+VI (weeks 30+40):

ponatinib 15 mg/day PO QD continuously, rituximab 375 mg/m2 IV (day 1), dexamethasone 10 mg/m2 PO (day 1-4), cytarabine 1.5 g/m2 IV (day 1+3+5), methotrexate 15 mg + cytarabine 40 mg + dexamethasone 4 mg IT (day 1). Maintenance: ponatinib 15 mg/day PO QD continuously 24 months. (Doses of IV methotrexate and cytarabine are reduced in patients \>55 years.)

Eligibility Criteria:
Inclusion Criteria:

* Patients with newly diagnosed, previously untreated, Ph-positive \[either t(9;22) and/or BCR-ABL positive\] B-precursor acute lymphoblastic leukemia;
* Age more than 18 years;
* Eligible to intensive chemotherapy, due to general health status;
* ECOG (Eastern Cooperative Oncology Group) performance status ≤2;
* Absence of significant liver disease, as defined by the following criteria: total serum bilirubin ≤1.5 x upper limit of normal (ULN), unless due to Gilbert's syndrome, alanine aminotransferase (ALT) ≤2.5 × ULN or ≤5 x ULN if leukemic involvement of the liver is present, and aspartate aminotransferase (AST) ≤2.5 × ULN or ≤5 x ULN if leukemic involvement of the liver is present;
* Adequate pancreatic function as defined by serum amylase and lipase ≤1.5 × ULN;
* Diagnostic sample of bone marrow (or peripheral blood with \>50% of blasts) available for central MRD assessment;
* Subject has provided written informed consent prior to any screening procedure.

Exclusion Criteria:

* Lymphoid blast crisis of chronic myelocytic leukemia (CML);
* Active serious infection not controlled by oral or intravenous antibiotics;
* Active known hepatitis B virus (HBV) or hepatitis C virus (HCV) or positive HIV serology;
* History of acute pancreatitis within 1 year of study or history of chronic pancreatitis;
* Uncontrolled hypertriglyceridemia (triglycerides \> 5.1 µmol/L);
* Clinically significant, uncontrolled or active cardiovascular disease, specifically including, but not restricted to: any history of myocardial infarction, stroke, or revascularization; unstable angina or transient ischemic attack within 6 months prior to enrolment; congestive heart failure within 6 months prior to enrolment or left ventricular ejection fraction (LVEF) less than lower limit of normal per local institutional standards; history of clinically significant (as determined by the treating physician) atrial arrhythmia; any history of ventricular arrhythmia; any history of venous thromboembolism including deep venous thrombosis or pulmonary embolism;
* Uncontrolled hypertension (diastolic blood pressure \>90 mmHg; systolic \>140 mmHg). Patients with hypertension should be under treatment on study entry to effect blood pressure control;
* Creatinine levels \> 160 µmol/L or estimated creatinine clearance of \< 50 mL/min;
* GI disease and/or major GI surgery that may significantly alter the absorption of study drug
* Hypersensitivity to the active substance or to any of the excipients, especially galactose intolerance.
* Taking any medications or herbal supplements that are known to be strong inhibitors of CYP3A4 within at least 14 days before the first dose of ponatinib;
* Female patients who are pregnant or breast feeding or patients of childbearing potential not willing to use a highly effective method of contraception during the study and for 3 months following the last dose of study drug;
* Male patients whose sexual partner(s) are women of childbearing potential who are not willing to use a highly effective method of contraception, one of which includes a condom, during the study;
* Patients with a history of another primary malignancy that is currently clinically significant or currently requires active intervention;
* Any concurrent severe and/or uncontrolled medical condition, which could, in the opinion of the investigator, compromise participation in the study;
* Concurrent participation in another clinical study with an investigational medical product.