Abstract：
Bispecific antibodies (bsAbs) have recently emerged as a promising platform for the treatment of several conditions, most importantly cancer. Based on the combination of two different antigen-binding motifs in a single macromolecule; bsAbs can either display the combined characteristics of their parent antibodies, or new therapeutic features, inaccessible by the sole combination of two distinct antibodies. While bsAbs are traditionally produced by molecular biology techniques, the chemical development of bsAbs holds great promises and strategies have just begun to surface. In this context, we took advantage of a chemical strategy based on the use of the Ugi reaction for the site-selective conjugation of whole antibodies and coupled the resulting conjugates in a bioorthogonal manner with Fab fragments, derived from various antibodies. We thus managed to produce five different bsAbs with 2 : 1 valency, with yields ranging from 20 % to 48 %, and showed that the affinity of the parent antibody was preserved in all bsAbs. We further demonstrated the interest of our strategy by producing two other bsAbs behaving as cytotoxic T cell engagers with IC50 values in the picomolar range in vitro.
摘要：
双特异性抗体（bsAb）最近已成为治疗多种疾病的有希望的平台，最重要的是癌症。基于单个大分子中两个不同的抗原结合基序的组合;bsAb可以展示其亲本抗体的组合特征，或者新的治疗特征，无法通过两种不同抗体的唯一组合。虽然bsAb传统上是通过分子生物学技术产生的，bsAbs的化学发展拥有巨大的承诺，战略刚刚开始浮出水面。在这种情况下，我们利用基于使用Ugi反应的化学策略进行全抗体的位点选择性缀合，并以生物正交方式将所得缀合物与Fab片段偶联，来自各种抗体。因此，我们设法生产了五种不同的2：1价bsAb，收益率从20%到48%不等，并显示亲本抗体的亲和力在所有bsAb中均得到保留。通过产生另外两种表现为细胞毒性T细胞接合剂的bsAbs，我们进一步证明了我们策略的兴趣，体外IC50值在皮摩尔范围内。
