Quantitative Analysis of the Potency of Equimolar Two-Drug Combinations and Combi-Molecules Involving Kinase Inhibitors In Vitro: The Concept of Balanced Targeting.

Suman Rao,Cédric Thauvin,Benoît Thibault,Anne-Laure Larroque-Lombard,Lisa Peyrard,Bertrand J Jean-Claude,Martin Rupp

doi:10.3390/ijms22179569

Suman Rao, Cédric Thauvin + Show 5 more

Open Access

https://doi.org/10.3390/ijms22179569

Copy DOI

Abstract

The median-effect principle proposed by Chou and Talalay is the most effective approach to parameterize interactions between several agents in combination. However, this method cannot be used to evaluate the effectiveness of equimolar drug combinations, which are comparative references for dual-targeting molecular design. Here, using data acquired through the development of “combi-molecules” blocking two kinases (e.g., EGFR-c-Src and EGFR-c-Met), we established potency indices for equimolar and dual-targeted inhibitors. If the fold difference (κ) between the IC50 of the two individual kinase inhibitors was >6, the IC50 of their equimolar combination resembled that of the more potent inhibitor. Hence, the “combi-targeting” of the two kinases was considered “imbalanced” and the combination ineffective. However, if κ ≤ 6, the IC50 of the combination fell below that of each individual drug and the combi-targeting was considered “balanced” and the combination effective. We also showed that combi-molecules should be compared with equimolar combinations only under balanced conditions and propose a new parameter Ω for validating their effectiveness. A multi-targeted drug is effective if Ω < 1, where Ω is defined as the IC50 of the drug divided by that of the corresponding equimolar combination. Our study provides a methodology to determine the in vitro potency of equimolar two-drug combinations as well as combi-/hybrid molecules inhibiting two different kinase targets.

Highlights

Introduction published maps and institutional affilThe implication of several signaling proteins in a complex network of signal transduction pathways is a commonly occurring event in advanced cancers
We propose that in vitro, a hybrid or combi-molecule can be considered effective in a given cell system when its IC50 for growth inhibition is lower than or equal to that of a balanced targeting combination
In order to profile the responses, we primarily screened a panel of cancer cell lines using single and equimolar combinations of clinically approved tyrosine kinase inhibitors (TKIs) targeting kinases engaged in synergistic crosstalk, and further extended the screening to kinase–DNA targeting drug combinations

Summary

Introduction

The implication of several signaling proteins in a complex network of signal transduction pathways is a commonly occurring event in advanced cancers. These signaling interactions between growth factor receptors (the epidermal growth factor receptor (EGFR), hepatocyte growth factor receptor (c-Met), platelet derived growth factor receptor (PDGFR), vascular endothelial growth factor receptor (VEGFR), etc.) and cytoplasmic non-receptor tyrosine kinases and transcription factors (c-Src, c-Abl, JAKs, STAT3, β-catenin, etc.) synergize to promote tumor growth, survival, and metastasis, and mediate resistance to targeted therapies through the activation of compensatory signaling pathways [1,2,3]. Over the past decade, we developed a novel approach termed “combi-targeting” that sought to design agents designated as “combi-molecules” capable of inducing tandem blockade iations.

Methods

Results

Conclusion