This is a single-arm, dose-escalation exploratory study evaluating the safety and efficacy of RN1201, a BCMA/CD19-targeted allogeneic CAR-T cell therapy, in patients with newly diagnosed multiple myeloma. Patients will receive lymphodepletion followed by a single infusion of RN1201. Primary endpoints include incidence and severity of treatment-emergent adverse events. Secondary endpoints assess response rate and minimal residual disease (MRD) status.

Inclusion Criteria:

1. Willingness to participate in the trial and provide written informed consent.

   • 2. Diagnosis of multiple myeloma (MM) per the 2017 revised WHO criteria.
   • 3. BCMA-positive multiple myeloma documented at screening or in prior medical records.
   • 4. Aged 18 - 70 years, any gender.
   • 5. Life expectancy of at least 12 weeks.
   • 6. Serum total bilirubin < twice the upper limit of normal (ULN); serum creatinine within normal range;
   • 7. alanine aminotransferase (ALT) and aspartate aminotransferase (AST) < three times ULN.
   • 8. ECOG performance status score of 0 - 2.
   • 9. Left ventricular ejection fraction (LVEF) ≥50% with no pericardial effusion.
   • 10. Ability to adhere to the study visit schedule and protocol requirements.

Exclusion Criteria:

1. Patients with serious active infections.

   • 2. Subjects with acquired or congenital immunodeficiency.

   • 3. Subjects with Class III/IV heart failure per NYHA criteria.

   • 4. Subjects with epilepsy or other central nervous system diseases.

   • 5. Subjects with a history of primary cancer, except:

     1. Resected non-melanoma (e.g., basal cell carcinoma)
     2. Cured carcinoma in situ (e.g., cervical, bladder, breast cancer)

   • 6. Systemic high-dose steroid use within 2 weeks before treatment.

   • 7. Pregnant, breastfeeding women, or those planning pregnancy in 6 months.

   • 8. Participation in other clinical trials within one month.

   • 9. Major surgery within 14 days before the first study drug dose.

   • 10. Any condition the investigator deems may raise subject risks or affect trial results.