Potent anti-tumor activity of a Lead-212 labelled MT1-MMP targeting Bicycle Radionuclide Conjugate ^TM

Abstract

²¹²Pb-BCY20603 is a Bicycle Radionuclide Conjugate^TM (BRC^TM), which comprises a bicyclic peptide that binds with high affinity to the tumor antigen MT1-MMP and a chelate of Lead-212, a potent alpha particle emitting radioisotope. ²¹²Pb-BCY20603 shows tumor targeting in rodent tumor xenograft studies, with radioactivity levels of >45% injected dose per gram (ID/g) 24 hours post injection. It is well tolerated and in rodent efficacy studies, shows potent antitumor activity after a single dose of 5 μCi. Complete tumor regressions were seen after 3 dosing cycles of 10 μCi, given two weeks apart, with no tumor regrowth at the end of the 100-day study.