# Evaluation of Antibody–Drug Conjugate Performances Using a Novel HPLC–DAD Method for Tumor-Specific Detection of DM4 and S‑Methyl-DM4

## TL;DR

This paper introduces a new HPLC method to measure the effectiveness of an antibody-drug conjugate in targeting tumors.

## Contribution

A novel HPLC-DAD method for simultaneously quantifying DM4 and S-methyl-DM4 in tissue matrices is developed and validated.

## Key findings

- The HPLC method was validated according to ICH guidelines for accurate quantification of DM4 and its metabolite.
- The method enables comparative assessment of ADC performance in preclinical tumor models.
- The ADC showed potent antitumor activity in models with LGALS3BP expression.

## Abstract

Antibody–drug
conjugates (ADCs) are an emerging class of
therapeutics that have gained interest in precision medicine for cancer
treatment, combining the targeted delivery capabilities of monoclonal
antibodies with the potent cytotoxicity of small-molecule drugs. The
goal is to enhance the therapeutic window by maximizing tumor cell
killing while minimizing off-target toxicity. Pivotal aims are precise
delivery of payload in the tumor site and a robust analytical methodology
to quantify the accumulation of it. 1959-sss/DM4, a novel ADC targeting
highly glycosylated LGALS3BP, which is a protein implicated in tumor
progression and metastasis, was developed. This ADC has shown potent
and durable antitumor activity in various preclinical models. A high-performance
liquid chromatography (HPLC) method according to ICH guidelines for
the simultaneous quantification of DM4 and its primary metabolite, S-methyl-DM4, in tissue matrices was validated. Was employed
a patient-derived neuroblastoma cell line (hNB CTRL), which naturally
lacks LGALS3BP expression, alongside a counterpart cell line (hNB
LGALS3BP) in which LGALS3BP expression was ectopically induced via
lentiviral-mediated gene transduction. A second metastatic model using
SKNAS neuroblastoma cells, which endogenously express LGALS3BP, was
utilized to study the kinetics of the payload. The approach allows
for the simultaneous detection of DM4 and S-methyl-DM4,
offering a valuable tool for the comparative assessment of ADC performance
in preclinical models.