Standardized workflow enables reproducibility of drug synergism detection: Results from a multi-center in vitro ring test on complex drug combinations in pancreatic cancer models

Veronica Barile; Maria Kuzikov; Weiyingqi Cui; Aleksandr Ianevski; Federica Iannelli; Maria Serena Roca; Jeanette Reinshagen; Hanna Axelsson; Alessandra Leone; Annika Jenmalm Jensen; Tero Aittokallio; Philip Gribbon; Brinton Seashore-Ludlow; Alfredo Budillon

doi:10.1016/j.biopha.2026.119575

Standardized workflow enables reproducibility of drug synergism detection: Results from a multi-center in vitro ring test on complex drug combinations in pancreatic cancer models

Biomed Pharmacother. 2026 Jun 1:200:119575. doi: 10.1016/j.biopha.2026.119575. Online ahead of print.

Affiliations

¹ Experimental Pharmacology Unit-Laboratory of Naples and Mercogliano (AV), Istituto Nazionale per lo Studio e la Cura dei Tumori "Fondazione G. Pascale" - IRCCS, Naples, Italy.
² Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Schnackenburgallee 114, Hamburg D-22525 Germany.
³ Chemical Biology Consortium Sweden (CBCS), Science for Life Laboratory, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
⁴ Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland.
⁵ Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland; Institute for Cancer Research, Department of Cancer Genetics, Oslo University Hospital, Oslo, Norway; Oslo Centre for Biostatistics and Epidemiology (OCBE), Faculty of Medicine, University of Oslo, Oslo, Norway.
⁶ Scientific Directorate, Istituto Nazionale per lo Studio e la Cura dei Tumori "Fondazione G. Pascale" - IRCCS, Naples, Italy. Electronic address: a.budillon@istitutotumori.na.it.

PMID: 42224741
DOI: 10.1016/j.biopha.2026.119575

Abstract

In the framework of REMEDi4ALL's mission to strengthen reproducibility in drug repurposing, we conducted a multicenter ring study to evaluate the reproducibility and translational value of combining histone deacetylase inhibitors (HDACi) with simvastatin (SIM) in pancreatic ductal adenocarcinoma (PDAC) cells. Initial inconsistencies due to misaligned protocols were resolved through harmonized SOPs across three European laboratories (INT-NA, ITMP, KI), enabling robust and comparable results. Under standardized procedures, valproic acid (VPA) and SIM emerged as the most synergistic combination, confirming our previous findings. The reproducible enhancement of antitumor activity when VPA/SIM was added to the standard chemotherapy (gemcitabine+nab-paclitaxel) further supports its translational relevance. Beyond validating this drug combination, the resulting open dataset enables systematic evaluation of technical confounders affecting drug sensitivity and provides a reference for data harmonization across heterogeneous assay platforms. All centers independently delivered high-quality data, demonstrating their readiness for future REMEDi4ALL repurposing efforts with enhanced rigor, robustness and interoperability.

Keywords: Cross-validation; PDAC; REMEDI4ALL; Reproducibility; repurposing; simvastatin; valproic acid.