目的 开发抗NF-κB受体激活蛋白配体（receptor activator of NF-κB ligand，RANKL）单克隆抗体（单抗）的纯化工艺。方法 采用深层过滤澄清上游细胞培养液去除细胞，澄清后的培养液经过亲和层析捕获、低pH病毒灭活、阴离子交换层析、阳离子交换层析、除病毒过滤、超滤浓缩、透析置换、除菌过滤等步骤，获得单抗原液。通过收率和产品相关杂质去除情况评价亲和层析纯化效果，通过监测穿透点计算填料的动态载量（dynamic binding capacity，DBC）；通过考察不同的pH和温度条件对样品的纯度和活性影响，确定低pH病毒灭活条件；通过考察目的蛋白在不同缓冲体系下的稳定性、工艺相关杂质去除情况，确定合适的阴离子交换层析缓冲体系并考察纯化效果和DBC；通过线性洗脱，分段收集考察杂质情况确定阳离子交换层析工艺参数；通过处理量、通量、流量衰减确定病毒滤器的型号；根据浓缩、透析及过滤除菌说明书和平台技术确定滤膜孔径、进液流速和跨膜压力，再根据确定的参数进行浓缩及透析置换；最后经0.2 μm膜除菌过滤获得原液，并检测纯度和杂质。结果 以MabSelect SuRe为亲和层析填料，DBC 45.3 mg/mL填料，25 mmol/L 三羟甲基氨基甲烷（Tris）-盐酸（pH7.5）为平衡液，150 mmol/L醋酸（pH2.8）为洗脱液；pH3.5灭活1 h；以Sepharose QFF为阴离子填料，最大DBC 60 mg/mL 填料，50 mmol/L Tris-醋酸（pH7.5）为平衡液；SP HP为阳离子填料，上样量21.9 mg/mL，100%缓冲液A（10 mmol/L柠檬酸，pH5.5）—100%缓冲液B（10 mmol/L柠檬酸+1 mol/L NaCl，pH5.5）线性洗脱20柱体积；以Viresolve Pro为除病毒过滤器；采用PLCTK 30 kDa超滤膜包（C流道）超滤透析浓缩至（40.00±5.00） mg/mL，并以等体积方式10倍体积置换成原液缓冲液后除菌过滤；单抗纯度和杂质含量均符合质量标准。结论 成功开发出抗RANKL单抗的纯化工艺，产品符合要求。

Objective To develop a purification process for anti-receptor activator of NF-κB ligand (RANKL) monoclonal antibodies.Methods The upstream cell culture supernatant was clarified by depth filtration to remove cells. The clarified harvest was then subjected to affinity chromatography (AC) capture, low-pH viral inactivation, anion-exchange chromatography (AEX), cation-exchange chromatography (CEX), viral filtration (VF), ultrafiltration/diafiltration (UF/DF), and sterile filtration to obtain the antibody bulk. AC purification efficiency was evaluated based on the yield and removal of product-related impurities. The dynamic binding capacity (DBC) of resin was calculated by monitoring the breakthrough point. Low-pH viral inactivation conditions were determined by evaluating the impact of pH and temperature conditions on sample purity and activity.The optimal AEX buffer system was determined by assessing the stability of target protein in different buffer conditions and the removal of process-related impurities. Purification efficiency and DBC were also evaluated. CEX process parameters were optimized using linear gradient elution and fraction collection to analyze impurity clearance. The VF filter type was selected based on throughput, flux, and flow decay.Membrane pore size, flow rate, and transmembrane pressure were determined based on UF/DF and sterile filtration manufacturer specifications and platform technology. Concentration and dialysis buffer exchange were performed accordingly. Finally, the bulk was obtained through a 0.2 μm membrane sterile filtration, and the purity and impurity were accessed.Results AC used MabSelect SuRe resin (DBC: 45.3 mg/mL resin) with 25 mmol/L Tris-HCl (pH7.5) for equilibration and 150 mmol/L HAc (pH2.8) for elution. Viral inactivation was accomplished with pH3.5 for 1 h. AEX used Sepharose Q FF resin (max DBC: 60 mg/mL resin) with 50 mmol/L Tris-HAc (pH7.5) for equilibration. CEX used SP HP resin of 21.9 mg/mL loading capacity with linear elution from 100% buffer A (10 mmol/L citrate， pH5.5) to 100% buffer B (10 mmol/L citrate + 1 mol/L NaCl， pH5.5) over 20 column volumes. Viresolve Pro was used for VF and PLCTK 30 kDa ultrafiltration cassette (C-channel) was used in UF/DF to concentrate to (40.00 ± 5.00) mg/mL, followed by 10× diafiltration and sterile filtration to yield bulk. Both the purity and impurity levels met predefined standards.Conclusion A robust process for anti-RANKL monoclonal antibody purification is successfully developed, yielding drug substance with acceptable qualities.