In several clinical trials, antibody company Micromet has demonstrated outstanding efficacy and safety of its bispecific BiTE antibodies which come with two binding sites: one for a cancer target and a second one for a T cell. As a result, T cells are recruited and guided directly to the tumor cell, initiating cancer cell death in a serial fashion.
In this week’s PNAS, researchers of the company demonstrate that the BiTE antibodies also can overcome the notorious resistance against conventional monoclonal antibodies arising in many cancer patients.
The researchers converted the anti-EGFR antibodies cetuximab (Erbitux) and panitumumab (Vectibix) into BiTE antibodies by adding the binding site for T cells. In animal models, these BiTE antibodies then showed a remarkably high potency (in the sub-picomolar range) against cancer cells with KRAS and BRAF-mutations which made them resistant to the original monoclonal antibodies.
