This is a single - arm, multi - cohort, open - label, multi - center Phase II clinical study. It aims to evaluate the efficacy and safety of F182112 combined with different administration regimens in patients with relapsed or refractory multiple myeloma.

The study plans to enroll approximately 90 patients with relapsed or refractory multiple myeloma at around 20 study centers.

Primary objective:

The objective response rate (ORR) of F182112 combined with different administration regimens in patients with relapsed or refractory multiple myeloma.

Secondary objective:

The efficacy of F182112 combined with different administration regimens in patients with relapsed or refractory multiple myeloma (complete response rate [CRR], progression - free survival [PFS], overall survival [OS], duration of response [DOR], time to response [TTR], time to progression [TTP], minimal residual disease - negative rate); The incidence and grade of adverse events (AE), serious adverse events (SAE), abnormal laboratory test indicators.

Inclusion Criteria:

• Be diagnosed with multiple myeloma according to the IMWG 2016 criteria.

• The previous treatment regimen must contain lenalidomide (lenalidomide must be used continuously for at least 2 cycles) and a proteasome inhibitor.

• Participants whose previous treatment regimen contained pomalidomide or who were intolerant to pomalidomide cannot be enrolled.

• Have an ECOG performance status score of 0 - 2.

• Meet at least one of the following measurable disease indicators:

  1. Serum M - protein ≥ 5 g/L.
  2. Urine M - protein ≥ 200 mg/24 h.
  3. Serum free light chain (FLC) test: Involved FLC level ≥ 100 mg/L and abnormal serum free light chain ratio (< 0.26 or > 1.65).

Exclusion Criteria:

• Patients with primary light - chain amyloidosis or plasma cell leukemia .
• Patients with symptoms of central nervous system involvement of multiple myeloma.
• Patients with a history of other malignancies other than multiple myeloma within 3 years before the first dose.
• Patients with active mucosal or visceral bleeding.
• Patients who have previously received BCMA - targeted therapy.