This study is an open-label, dose-escalation and efficacy-expansion Phase I clinical trial to evaluate the safety, tolerability, PK profile, immunogenicity, and preliminary antitumor activity of QLS2313 as a monotherapy in patients with relapsed/refractory hematological malignancies.

Inclusion Criteria:

1. Males or females aged ≥ 18 years；
2. Patients with relapsed/refractory hematological malignancies, specifically patients with B-cell NHL or CLL/small lymphocytic lymphoma (SLL) as defined by the 2022 World Health Organization (WHO) classification, who are relapsed/refractory and have no standard of care available as judged by the investigator;
3. Having a measurable disease defined by appropriate disease response criteria;
4. Subjects with sufficient organ function prior to the first dose of the investigational drug
5. Eastern Cooperative Oncology Group (ECOG) performance status (PS) score: 0 or 1

Exclusion Criteria:

1. Previous treatment with a CD79b/CD3/CD20 trispecific antibody；
2. Known central nervous system (CNS) involvement；
3. Known history of allogeneic organ transplantation or allogeneic hematopoietic stem cell transplantation/bone marrow transplantation；
4. Treatment with autologous stem cell transplantation within 3 months;
5. Prior genetically modified adoptive cell therapy (e.g., chimeric antigen receptor T cells [CAR-T] and natural killer cells [CAR-NK]) within 3 months
6. Presence of viral, bacterial or uncontrolled fungal infection requiring intravenous drug infusion within 1 week prior to the first dose
7. Presence of chronic or acute active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, defined as HBV-5 test at screening indicating active infection (positive HBsAg and/or positive HBcAb) with HBV-DNA > ULN, or positive HCVAb and positive HCV-RNA, allowed for antiviral therapy.