During the entire 1st year of the project, Elthera worked on the optimization of the drug-like properties of an L1CAM-targeting bispecific antibody, involving several rounds of protein engineering, biophysical and pharmacological characterization. The second year was dedicated to the development of an anti-L1CAM antibody drug conjugate (ADC). By the end of 27 months, Elthera had identified an anti-L1CAM ADC with good biophysical and pharmacokinetic properties and excellent anti-tumor efficacy both in vitro and in vivo. This ADC was nominated the clinical development candidate (“ELT048”) and was tested in an exploratory safety and tolerability study in cynomolgus monkeys. In RP3, the gross pathology analysis and full histopathology analysis of all organs was conducted. ELT048 was found to be well tolerated and no treatment-related macroscopic or microscopic changes were observed in any of the examined tissues/organs, whereas good exposure and pharmacodynamic activity of ELT048 was confirmed in PK/PD assays. Additional in vitro and in vivo pharmacological studies indicated that ELT048 had an acceptable therapeutic index, thus supporting its clinical developability. Fund raising and business development activities took place during the whole duration of the project and were further intensified during the third reporting period to finance or partner further development. As a result of these endeavours, Elthera entered into a license agreement with LegoChem Biosciences on 13th Feb 2023. Under the terms of the agreement, Elthera grants LegoChem a worldwide exclusive license to further develop and commercialize the anti-L1CAM ADC and any other products containing Elthera’s proprietary anti-L1CAM antibodies. By closing this license agreement, Elthera has met the ultimate goal of the project.
