A single-center, single-arm, open-label, interventional, phase II clinical trial to evaluate the efficacy and safety of InO in B-ALL achieved CR/CRi after 1L induction chemotherapy with positive minimal residual disease.

Inclusion Criteria:

1. New diagnosed B-ALL in hematologic complete remission (CR) after 1L induction chemotherapy with MRD positive. Molecular disease or MRD is defined by a value of at least of 10-4 (0.01%) by multicolor flow cytometry.

2. Age ≥18 years

3. ECOG PS score: 0 to 2

4. Functions of the main organs are normal, if the following criteria are met:

   1. Total bilirubin (BIL) ≤ 1.5 × upper limit of normal (ULN)
   2. Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) ≤ 2.5 × ULN
   3. Serum creatinine ≤ 1.5 × ULN
   4. Creatinine clearance ≥ 30 ml/min

5. No active or co-existing malignancy with a life expectancy of less than 12 months

6. Patients are voluntarily enrolled into the study and have good compliance, and the Informed Consent Form (ICF) needs to be signed.

Exclusion Criteria:

1. Mixed lineage leukemia

2. Clinically significant liver disease such as history of veno-occlusive disease (VOD)/ sinusoidal obstruction syndrome (SOS)

3. Patients with severe and / or uncontrolled diseases, such as:

   1. Unstable angina pectoris, symptomatic congestive heart failure, myocardial infarction within 6 months before randomization, severe uncontrolled arrhythmias; uncontrolled blood pressure (systolic blood pressure > 140 mmHg, diastolic blood pressure > 90 mmHg)
   2. Liver diseases such as cirrhosis, decompensated liver disease, acute or chronic active hepatitis
   3. Known to be human immunodeficiency virus positive (HIV+)
   4. Active and uncontrolled disease/infection as judged by the treating physician
   5. Active central nervous system (CNS) or extramedullary disease
   6. Patients who have other malignant tumors at the same time; patients who are evaluated by the investigator to have concomitant diseases that seriously endanger the safety of the patients or affect the patients to complete the study

4. Pregnant or nursing women

5. Unable or unwilling to sign the consent form

6. Monoclonal antibodies therapy within 2 weeks before study entry

7. Radiotherapy or cancer chemotherapy (except for induction chemo) or any investigational drug within 2 weeks before study entry

8. Patients who have severe allergies (≥ grade 3) to active ingredients and any excipients of InO

9. Patients in other situations who are evaluated by the investigator to be ineligible