With the most advanced technology and years of experience in the antibody engineering field, Creative Biolabs now provides custom construction and production services for tandem scFv. Tandem scFvs are recombinant fusion proteins consisting of two single-chain variable fragments. The two scFvs can bind two receptors or ligands simultaneously or retarget immune cells, such as T cells and NK cells, to disease tissues. The latter format is also named bispecific immune cell engagers, such as bispecific T cell engagers and bispecific NK cell engagers, and have been widely studied in tumor immunotherapy. One of the scFvs binds to immune cells via their markers, such as CD3 of T cells, and the other to tumor cells via tumor-associated antigen (TAA).
Fig. 1 The antibody principle. (Baeuerle. 2009)
Our scientists are fully aware that the construction of tandem scFv is far more complicated than linking just two scFv fragments together. There are details need to be taken into consideration when designing the molecule, which may greatly affect the stability, specificity, and homogeneity. The orientation of VH and VL as well as the linkers (between the two scFvs or inside each scFv) may greatly affect the stability, expression level, and binding ability. In some cases, only one of these forms can produce functional molecules. Therefore, it is suggested that pre-experiment is necessary by changing the orientation of VH-VL, expressing in small scale and testing the activity before scale-up production.
Tandem scFv therapeutics are currently being evaluated in different clinical indications. Several tandem scFv programs have entered the clinic and published results from these programs show evidence of clinical remissions. The specific BiTE BLINCYTO® developed by Amgen has been approved by FDA for lymphoma and B cell ALL therapy. Based on the investigations on dozens of bispecific molecules in pre-clinical and clinical trials, scientists from Creative Biolabs are pleased to work on your project for the discovery of new bispecific antibodies for cancer therapy.