• Relapsed or refractory patients with T-lineage acute lymphoblastic leukemia or T-lymphoblastic lymphoma

• 18 years old or older

• Bone marrow or peripheral blood involvement with ≥5% lymphoblasts or measurable residual disease with \>10-4 level detected by multiparameter flow cytometry or next-generation sequencing (NGS)-based measurable residual disease (ClonoSEQ, Adaptive Technologies). Patients with isolated extramedullary disease that is measurable by computed tomography (CT) scan are also eligible.

• Eastern Cooperative Oncology Group performance status 0-2.

• Adequate organ function as defined by all of the following:

‣ Creatinine clearance ≥50 mL/min, determined by the Cockroft-Gault formula, or measured by a 24-hour urine collection.

⁃ Aspartate transaminase (AST) and alanine transaminase (ALT) ≤2.5 x upper limit of normal (ULN) and bilirubin ≤1.5 x ULN (unless considered due to Gilbert's syndrome or of non-hepatic origin i.e,, leukemic involvement). For patients with Gilbert's syndrome, bilirubin ≤1.5 x of their baseline bilirubin level will be required.

• Participants must be at least 2 weeks from major surgery or radiation therapy. A wash-out period of 4 half-lives is required for patients who participated in other investigational trials. These patients must have recovered from clinically significant toxicities related to these prior treatments.

• Participants must voluntarily sign and date an informed consent, approved by an Independent Ethics Committee (IEC)/Institutional Review Board (IRB), prior to the initiation of any screening or study-specific procedures.

• Females of childbearing potential will use effective contraception during protocol treatment and for at least 8 months after the last dose. Males with female partners of reproductive potential will use effective contraception during protocol treatment and for at least 5 months after the last dose. A patient is of childbearing potential if, in the opinion of the treating investigator, he/she is biologically capable of having children and is sexually active. Female patients who are not of childbearing potential (ie, meet at least one of the following criteria):

• a. Have undergone hysterectomy or bilateral oophorectomy; or have medically confirmed ovarian failure; or are medically confirmed to be post-menopausal (cessation of regular menses for at least 12 consecutive months with no alternative pathological or physiological cause).

• Participants who are willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures.