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

Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia (Ph+ B-ALL) or blastic transformed Chronic Myeloid Leukemia (myeloid or lymphoid) (CML-BP) represent a group of high-risk disease. The outcome has improved since the introduction of tyrosine kinase inhibitors (TKIs). However, a significant proportion of patients still relapse despite undergoing allogeneic (allo-) hematopoietic stem cell transplant (HSCT) and post-transplant maintenance with TKIs. Moreover, many patients may not be able to tolerate the standard recommended dose of TKIs due to cytopenia especially during the early phase after transplant.

Asciminib is a first in class allosteric inhibitor that works by a mechanism totally different from the current TKIs in market. Its safety and efficacy have been studied in previous studies. We therefore postulate that combination of standard ATP-competitive TKIs (our current standard of care) and asciminib as post allo-HSCT maintenance can more effectively reduce risk of relapse post-transplant without increased toxicities.

This is a two-arm, parallel group, single-center, prospective, open-label, randomized clinical study to investigate the efficacy and safety of adding asciminib to the standard-of-care for post allogenic HSCT maintenance in patients with Ph+ B-ALL or CML-BP to prevent post-HSCT relapse.

Subjects in study group will receive Asciminib plus standard of care (SOC) while those in control group will receive standard of care. Eligible subjects will be randomized into study group and control group in a 2:1 ratio.

The subjects in study group commence study drug (Asciminib) for post-transplant maintenance at 80 mg QD (in combination with nilotinib or dasatinib) or 60 mg QD (in combination with imatinib) after stable count recovery (i.e. absolute neutrophile count [ANC] ≥ 1.0 × 109/L, granulocyte colony-stimulating factor (G-CSF) independent and platelet ≥ 50 × 109/L, transfusion independent). SOC TKI will be added from 5th week onwards after.

Inclusion criteria

• The subject (or the subject's legally acceptable representative, if applicable) must be capable of giving written informed consent and, prior to the commencement of any study-specific procedure, must sign an informed consent form (ICF) indicating the consent on the subject's voluntary participation in the study and compliance with the requirements and restrictions listed on the ICF.
• Age ≥ 18 years
• Patients with Ph+ B-ALL or CML-BP, who had undergone allogeneic HSCT
• Patients must have received TKI therapy in induction/consolidation therapy
• Absolute neutrophil count ≥ 1.0 × 109/L
• Platelet count ≥ 50 × 109/L

Exclusion criteria

• Patients with known atypical transcript that cannot be measured by available polymerase chain reaction (PCR) methods.
• Eastern Cooperative Oncology Group (ECOG) performance status ≥ 2
• Uncontrolled hypertension
• Corrected QT interval (QTc) > 460 milliseconds for women or > 450 milliseconds for men
• Amylase and lipase values > 3 × upper limit of normal
• Patients refused standard TKI maintenance post-HSCT
• Unable to comply with study requirements
• Patients taking ponatinib as choice of TKI
• Patients with documented T315I mutation