2302P - Efficacy assessment of targeted and immunotherapies for personalised treatment of melanoma using 2D and 3D ex-vivo assays

Background

Ex-vivo functional drug assessment has been successfully tested to guide treatment decisions with higher predictive value for multiple malignancies. Similar methods can also be used to test the personalised efficacy of standard-of-care drugs for advanced melanoma. We are currently developing an ex-vivo high throughput pre-clinical workflow comparing different ex-vivo models with a range of clinically approved and experimental systemic drugs including immunotherapies.

Methods

A high-content immunofluorescence (IF) microscopy-based viability assay for drug screening has been developed and optimised using melanoma cell lines and four targeted inhibitors. Upon exposure, the drug efficacy profiles were generated by counting fluorescently labelled melanoma cells. A 3D spheroid-pbmc coculture model is currently being optimised for the efficacy assessment of Immune Checkpoint Inhibitors currently used to treat melanoma patients. The immunotherapy efficacy will be assessed by immune cell activation and spatial distribution of immune cells in relation to tumour spheroids. Currently, we are recruiting stage III/IV melanoma patients to collect metastatic lymph nodes which are being used for the 2D and 3D assays. The drug efficacy results will be correlated with the corresponding patient’s clinical follow-up data.

Results

A 2D image based cell viability assay has been optimised using melanoma cell lines. Dose-response curves have been successfully generated with IC50 values for targeted inhibitors using fluorescently labelled melanoma cell lines in the 2D imaging assay. For 3D coculture, spheroids were successfully generated from cell lines and patient samples in hydrogel sandwich assay, hydrogel dot matrix assay, and 3% methyl cellulose- media floating assay. The spheroids and isolated PBMCs from patients and healthy donors are now being used to optimise the coculture assay for ICB efficacy assessment.

Conclusions

The preliminary data shows, the project can provide valuable insight into the applicability and translational potential of ex vivo screening guided personalised treatment for advanced melanoma patients and identify novel, repurposed, or combination treatments with improved clinical outcomes.

Clinical trial identification

NCT05231655.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Commonwealth Scholarship Commission, UK Sheffield Teaching Hospitals NHS Foundation Trust University of Sheffield.

Disclosure

All authors have declared no conflicts of interest.