The goal of this open label, dose escalation phase 1b clinical trial is to investigate the safety, tolerability, pharmacokinetic, pharmacodynamics, immunogenicity and preliminary clinical efficacy of QLS4131 in subjects with systemic lupus erythematosus (SLE). The main questions it aims to answer are:
* The safety, tolerability and maximum tolerated dose (MTD) of QLS4131 for Injection in participants with SLE.
* The recommended Phase 2 dose (RP2D) of QLS4131 for Injection in participants with SLE.
Participants will be administered different target dose of QLS4131 for Injection only once. A step-up dosing approach will be implemented at high dose level as determined by the safety monitoring committee.