Asciminib & Standard-of-Care Integration in Maintenance Therapy for POST Allogeneic Stem Cell Transplant (Allo-HSCT) of Patient With Ph+ B-ALL or Blastic Transformed CML

The goal of this clinical trial is to learn if Asciminib, a first in class allosteric inhibitor, as a add-on maintenance therapy can provides benefits and further prevents relapse in post allogenic hematopoietic stem-cell transplant (HSCT) of patients with Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia (Ph+ B-ALL) or blastic transformed Chronic Myeloid Leukemia (CML-BP). The main questions it aims to answer are: Would Ascminib add-on maintenance therapyimprove Morphological relapse-free survival rate? Would Ascminib add-on maintenance therapy improve Molecular relapse-free survival and Overall survival ? Any toxicity or intolerable events during Ascminib add-on maintenance therapy? Researchers will compare Study arm (Ascminib plus tyrosine-kinase inhibitors \[TKIs\]) and Control arm (TKIs only) to see if Ascminib add-on maintenance therapy would provide better relapse-free survival (RFS) with optimal tolerability. Participants will * Enrolled and Randomized into either Study arm or Control arm * Take Ascminib plus selected TKI or selected TKI only according to schedule * Visit the clinic once every 2-4 weeks for checkups and tests * Record and Report any adverse event and graft-versus-host-disease (GvHD) development