This is a multi-center, open-label, Phase 1/2 study to evaluate the safety, tolerability, Pharmacokinetics, pharmacodynamics and Preliminary Efficacy of CM313 in Subjects with Relapsed or Refractory Multiple Myeloma.

Inclusion Criteria:

• Subjects age ≥ 18 years.
• Subjects diagnosed with multiple myeloma.
• Subjects with measurable lesions.
• Women of childbearing potential with negative pregnancy testing.
• Subjects voluntarily signed the Informed Consent Form and were able to comply with the provisions of this protocol.

Exclusion Criteria:

• Previous treatment with any anti-CD38 therapy.
• Vaccinated with live, attenuated vaccine within 4 weeks prior to the first dose.
• Positive for human immunodeficiency virus (HIV) antibodies.
• Syphilis antibody positive.