Phase 1 Study of 6MW5311 in Adults With Relapsed or Refractory Blood Cancers

Inclusion Criteria:

1. Age 18 years or older at the time of signing the informed consent form; male or female.

2. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 for the dose-escalation part, or 0 to 2 for the dose-expansion part.

3. Life expectancy greater than 3 months.

4. Multiple myeloma (MM): histologically and/or cytologically confirmed MM per International Myeloma Working Group (IMWG) 2016 criteria, with at least 3 prior lines of MM therapy, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody.

   • Chronic myelomonocytic leukemia (CMML): morphologically confirmed by bone marrow examination per World Health Organization (WHO) 2016 classification, with relapsed disease or failure of prior therapy.
   • Acute myeloid leukemia (AML; dose-expansion part only): morphologically confirmed acute myelomonocytic leukemia or acute monocytic leukemia per WHO 2016 classification, meeting the protocol definition of relapsed or refractory AML.

5. MM only: measurable disease at screening.

6. Adequate hematologic function at screening:

7. Able to understand and comply with the protocol requirements, willing to participate in the clinical study, and able to provide written informed consent.

Exclusion Criteria:

• 1. AML and CMML only: any other anticancer therapy within 2 weeks before the first dose of study drug.

MM only: prior anticancer therapy within the following intervals before the first dose of study drug:

• small-molecule targeted therapy within 4 weeks or 5 half-lives, whichever is shorter;

• antibody therapy within 3 weeks;

• cytotoxic chemotherapy, proteasome inhibitor therapy, or traditional Chinese medicine (including Chinese patent medicine) with an anticancer indication within 2 weeks;

• immunomodulatory agent within 1 week;

• chimeric antigen receptor T-cell (CAR-T) therapy within 3 months;

• radiotherapy within 1 week. 2. Receipt of any other investigational drug within 4 weeks before the first dose of study drug.

  3. Prior allogeneic stem cell transplant; or autologous stem cell transplant within 3 months before the first dose of study drug.

  4. Planned stem cell transplant during the study. 5. Prior treatment with a LILRB4-targeted therapy.