目的:有人担心生物治疗药物产品中的亚可见聚集体对患者安全构成风险。我们研究了诱导免疫原性反应所需的生物治疗聚集体的阈值。
结果:在基于细胞的测定中测试了高度聚集的样品,并以取决于颗粒数量的方式诱导了细胞反应。免疫激活的阈值因疾病状态而异(癌症,类风湿性关节炎,过敏),伴随治疗,和粒子数。与健康的捐赠者相比,疾病状态患者在晚期(7天)表现出相等或较低的反应,这表明他们可能不会有更高的对聚集体作出反应的风险。使用Xeno-het小鼠评估体内免疫激活的阈值。尽管高度聚集的样品(〜1,600,000个颗粒/mL)在小鼠中诱导了微弱和短暂的免疫原性反应,该样品的100倍稀释(~16,000个颗粒/mL)不诱导免疫原性。为了确认这个结果,亚可见颗粒(高达约18,000个颗粒/毫升,在具有代表性的给药实践(通过IV导管输注药物产品时产生)下产生的包含聚集体和硅油滴)在基于细胞的测定中没有诱导反应,或者在3期临床试验中似乎增加了不良事件或免疫原性。
结论:生物治疗聚集体在体外引发免疫反应的能力,在体内,在临床上依赖于大量的颗粒。这表明聚集物诱导免疫原性反应的阈值高,其远远超过标准生物治疗药物产品中所见。
OBJECTIVE: There is concern that subvisible aggregates in biotherapeutic drug products pose a risk to patient safety. We investigated the threshold of biotherapeutic aggregates needed to induce immunogenic responses.
RESULTS: Highly aggregated samples were tested in cell-based assays and induced cellular responses in a manner that depended on the number of particles. The threshold of immune activation varied by disease state (cancer, rheumatoid arthritis, allergy), concomitant therapies, and particle number. Compared to healthy donors, disease state patients showed an equal or lower response at the late phase (7 days), suggesting they may not have a higher risk of responding to aggregates. Xeno-het mice were used to assess the threshold of immune activation in vivo. Although highly aggregated samples (~ 1,600,000 particles/mL) induced a weak and transient immunogenic response in mice, a 100-fold dilution of this sample (~ 16,000 particles/mL) did not induce immunogenicity. To confirm this result, subvisible particles (up to ~ 18,000 particles/mL, containing aggregates and silicone oil droplets) produced under representative administration practices (created upon infusion of a drug product through an IV catheter) did not induce a response in cell-based assays or appear to increase the rate of adverse events or immunogenicity during phase 3 clinical trials.
CONCLUSIONS: The ability of biotherapeutic aggregates to elicit an immune response in vitro, in vivo, and in the clinic depends on high numbers of particles. This suggests that there is a high threshold for aggregates to induce an immunogenic response which is well beyond that seen in standard biotherapeutic drug products.