Abstract 2601
Background
Immune checkpoint inhibitors (ICIs) acting against CTLA-4 and PD-1 represent a strenght therapy in patients (pts) with metastatic melanoma (MM). Antineoplastic activity of ICIs through the activation of immune cells in tumor lesions raised challenge in evaluation of treatment response by imaging. Aim of this study was to compare diagnostic accuracy of different 18F-FDG PET/CT parameters (Metabolic Tumor Volume, MTV; Total Lesion Glycolisis, TLG; Maximum Standardised Uptake Value, SUVmax) to predict therapy response and clinical outcome in pts with MM treated with Ipilimumab (Ipi) and Nivolumab (Nivo) or Pembrolizumab (Pem) and to check for accuracy differences specific for the class of treatment.
Methods
57 MM pts receiving Ipi (25) or PD-1 inhibitors (Nivo 19; Pem 13) who performed a 18F-FDG PET/CT scan at the beginning (PET0) and after completion of Ipi or during anti PD-1 (PET1), were retrospectively evaluated. Response at PET1 was classified as PD, SD, PR and CR according to RECIST 1.1, EORTC criteria and by percentage change of MTV and TLG (cut off values: +43% for PD and -43% for PR, calculated by ROC analysis) of up to 5 target lesions. PET Response Evaluation Criteria for Immunotherapy (PERCIMT) were assessed alone and with the previously described parameters. Performance of each criteria at PET1 to predict pts having clinical benefit (CR, PR and SD) and no clinical benefit (PD) at 6 months since starting ICIs were assessed and correlated to time-to-progression.
Results
For Ipi pts group, best predictors of response were: variation of MTV (Sensitivity 1; Specificity 0.84; accuracy 0.96) and TLG (Se 0.89; Sp; 93.8; acc 0.92), with PERCIMT criteria for progressive disease. In anti-PD1 group overlapping predictivity values were found for EORTC, MTV and TLG (Se 0.95; Sp 1; Acc 0.97). Reliability of above parameters was also confirmed in predicting pts progression free survival at 12 and 24 months.
Conclusions
18F-FDG PET/CT performed 3 months later the first administration could predict response to ICIs and long-term patient clinical outcome. Performance of 18F-FDG PET/CT parameters and criteria in predicting response to ICIs is influenced by the class of treatment.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Local Ethic committee.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4634 - Comparative molecular analyses between microsatellite stable BRAFV600E mutant colorectal cancers and BRAFV600E mutant melanomas.
Presenter: Mohamed Salem
Session: Poster Display session 3
Resources:
Abstract
3264 - A novel preclinical model of RAF-independent MEK1 mutant tumors and its treatment with novel ATP competitive MEK inhibitor
Presenter: Luca Hegedus
Session: Poster Display session 3
Resources:
Abstract
4918 - HER2 inhibition in Aggressive Squamous Cell Carcinomas driven by a common MET Sema Domain Polymorphism
Presenter: Nur Afiqah Mohamed Salleh
Session: Poster Display session 3
Resources:
Abstract
2426 - ADAM9 as a target for lung cancer treatment
Presenter: Yuh-pyng Sher
Session: Poster Display session 3
Resources:
Abstract
5537 - Novel polyurea/polyurethane nanocapsules loaded with a tambjamine analog to improve cancer chemotherapy delivery and safety in lung cancer
Presenter: Marta Perez Hernandez
Session: Poster Display session 3
Resources:
Abstract
1597 - Discovery of Clinical Candidate DBPR112, a Furanopyrimidine-based Epidermal Growth Factor Receptor Inhibitor for the Treatment of Non-Small Cell Lung Cancer
Presenter: Hsing-pang Hsieh
Session: Poster Display session 3
Resources:
Abstract
3543 - Molecular characteristics in lung squamous cell carcinomas dependent on TP53 status – putative targets
Presenter: Vilde Haakensen
Session: Poster Display session 3
Resources:
Abstract
4111 - Comparison of molecular profiles between primary tumour and matched metastasis in non-small cell lung cancer
Presenter: Asuka Kawachi
Session: Poster Display session 3
Resources:
Abstract
4559 - Treatment with BLU-667, a potent and selective RET inhibitor, provides rapid clearance of ctDNA in Patients with RET-altered Non-Small Cell Lung Cancer (NSCLC) and Thyroid Cancer
Presenter: Giuseppe Curigliano
Session: Poster Display session 3
Resources:
Abstract
2501 - Triple MET/SRC/PIM inhibition in MET addicted tumors
Presenter: Ilaria Attili
Session: Poster Display session 3
Resources:
Abstract