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
5389 - Two-weekly accelerated BEP (aBEP) regimen as induction chemotherapy (CT) in intermediate and poor prognosis patients (pts) with nonseminomatous germ cell tumors (NSGCT): final results of phase II trial.
Presenter: Alexey Tryakin
Session: Poster Display session 3
Resources:
Abstract
2934 - Differential expression of circulating miR375 and miR371 to detect teratoma and viable germ cell malignancy
Presenter: Lucia Nappi
Session: Poster Display session 3
Resources:
Abstract
3585 - Prognosis of anaemia in disseminated testicular germ cell tumours. On behalf of the Spanish Germ Cell Cancer Group (SGCCG)
Presenter: Esmeralda Garcia Torralba
Session: Poster Display session 3
Resources:
Abstract
2254 - The Effects Of Primary Testicular Tumor Localization On Prognosis In Patients With Nonseminomatous Testis Cancer
Presenter: Birol Yildiz
Session: Poster Display session 3
Resources:
Abstract
4505 - Initial Results of a Phase II study of Nivolumab and Ipilimumab in Metastatic Adrenal Tumors.
Presenter: Matthew Campbell
Session: Poster Display session 3
Resources:
Abstract
3369 - NEMIO: a randomized phase II trial evaluating efficacy and safety of dose dense MVAC (ddMVAC) + durvalumab +/- tremelimumab as neoadjuvant treatment in patients with bladder muscle-invasive urothelial carcinoma
Presenter: Constance Thibault
Session: Poster Display session 3
Resources:
Abstract
2075 - KEYNOTE-866: Phase 3 Study of Perioperative Pembrolizumab (pembro) or Placebo (pbo) in Combination With Neoadjuvant Chemotherapy in Cisplatin (cis)-Eligible Patients (pts) With Muscle-Invasive Bladder Cancer (MIBC)
Presenter: Arlene Siefker-Radtke
Session: Poster Display session 3
Resources:
Abstract
4824 - KEYNOTE-905: A Phase 3 Study of Cystectomy Plus Perioperative Pembrolizumab Versus Cystectomy Alone in Cisplatin (cis)-Ineligible Patients (pts) With Muscle-Invasive Bladder Cancer (MIBC)
Presenter: Matthew Galsky
Session: Poster Display session 3
Resources:
Abstract
2253 - Phase 3 LEAP-011 trial: First-Line Pembrolizumab With Lenvatinib in Patients With Advanced Urothelial Carcinoma Ineligible to Receive Platinum-Based Chemotherapy
Presenter: Yohann Loriot
Session: Poster Display session 3
Resources:
Abstract
4310 - PULSE : A Single Arm Trial Assessing The Activity and Safety of Avelumab Immunotherapy Maintenance among Patients With Locally Advanced or Metastatic Squamous Cell Penile Carcinoma (mSCPC).
Presenter: Noemie Gassian
Session: Poster Display session 3
Resources:
Abstract