Curative effect in xenografted mice
A HER2-targeting Affibody® molecule with prolonged half-life using Albumod™ technology and coupled to the therapeutic radionuclide 177Lu conferred a significant survival benefit to mice bearing microscopic human tumors. In contrast to the vehicle groups, mice treated with targeted Affibody® molecules did not develop any detectable tumors (P < 0.001).

 

Tumor-free survival of BALB/c nu/nu mice versus time. Groups of mice (n=10) were grafted s.c. with HER2-expressing SKOV-3 cancer cells one week prior to therapy. Animals were treated with a single injection of 177Lu-labeled tumor targeting Affibody® molecule (16-23 MBq, red) versus non-tumor targeted radioactivity (23 MBq, blue) or vehicle only (black). Adapted from Tolmachev et al 2006.

Therapeutic effect in solid tumors
Debulking of established tumors by administration of an Affitoxin. The Affitoxin consists of a modified version of Pseudomonas Exotoxin A targeted by a HER2-specific Affibody® molecule. The effect is dependent on targeted delivery of the toxin to the tumors via the Affibody® molecule, a control Affibody® molecule fused to the toxin did not have any effect (data not shown).

Tumor volume over time after administration of Affitoxin, 250 µg/kg (red line) or vehicle (green line) to groups of mice, n=5-7. Animals were treated by repeated administrations (black arrows). Adapted from Zielinski et al 2009 and Jacek Capala, NCI/NIH, personal communication.