Front-line treatment of Philadelphia positive (Ph+)/BCR-ABL positive Acute Lymphoblastic Leukemia (ALL) with AP24534 (Ponatinib), a new potent tyrosine kinase inhibitor (TKI). A phase II exploratory multicentric study in patients more than 60 years old or unfit for a program of intensive chemotherapy and stem cell transplantation. (GIMEMA LAL 1811)