A Study to Evaluate the Safety and Efficacy of SCTC21C in Combination With Bortezomib, Cyclophosphamide, and Dexamethasone in Patients With Newly Diagnosed Systemic Light-Chain Amyloidosis (NDSLCA)

This study comprises two phases: Part 1 is the safety run in, while Part 2 is a randomized, controlled, open-label, multicenter study. Both parts are divided into three stages: the screening period (up to 28 days before first dose/randomization), the treatment period (from Cycle 1 [28 days] Day 1 and continues until disease progression or unacceptable toxicity), and the follow-up period (Postintervention). Safety endpoints include treatment-emergent adverse events , treatment-related adverse events, serious adverse events, clinical laboratory tests, vital signs, physical examinations, electrocardiograms , etc. Efficacy endpoints include Overall Complete Hematologic Response (CHR)，objective response rate (ORR), Hematologic Very Good Partial Response (VGPR) or Better Rate, Overall Survival (OS).

Inclusion criteria

• Histopathological diagnosis of amyloidosis based on detection by immunohistochemistry and polarizing light microscopy of green bi-refringent material in congo red stained tissue specimens or characteristic electron microscopy appearance;
• Measurable disease of amyloid light-chain (AL) amyloidosis;
• One or more organs impacted by AL amyloidosis according to consensus guidelines
• Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0, 1 or 2

Exclusion criteria

• Prior therapy for AL amyloidosis;
• Other amyloidosis;
• Uncontrolled infection.
• Subjects with conditions that may affect safety or efficacy assessments include, but are not limited to, cardiovascular, respiratory, endocrine/metabolic, immune system, hepatic, gastrointestinal (such as gastrointestinal bleeding, perforation, ulcers, etc.), and malignant neoplasms, and are deemed clinically significant by the investigator.
• Subjects who have undergone major surgery or experienced significant trauma within 4 weeks prior to the first use of the investigational drug, or who require elective surgery during the trial period.
• Received a live or attenuated vaccine within 30 days prior to the first dose; Female subjects who are currently breastfeeding.
• Subjects with mental disorders or poor compliance, or other circumstances deemed unsuitable for participation in this study by other investigators.