Abstract 1084
Background
Immune checkpoint inhibitors (ICI) have been demonstrated to improve overall survival (OS) in several cancer types. Atypical patterns of response have been reported including durable responses, pseudoprogression and hyperprogression. We evaluated the occurrence of dissociated response (DR) on immunotherapy.
Methods
We retrieved all patients treated at the Curie Institute with an ICI either alone or in combination with another ICI in the frame of a clinical trial. Patients had to have a baseline CT-scan and at least one follow-up CT-scan, and at least two target lesions (TLs). There was no selection on tumor type. All TLs on CT-scans were assessed by two independent readers according to RECIST 1.1. Three types of DR were evaluated: 1) one TL in partial or complete response (CR/PR) and one progressive TL (DR1), 2) one stable TL and one progressive TL (DR2), and 3) one TL in CR/PR and one stable TL (DR3). Finally, we evaluated the impact of previous radiotherapy and biopsy on TLs on the occurrence of DRs.
Results
1,246 measures of 272 TLs were performed in the 100 patients who met our inclusion criteria. The median number of TLs per patient was 3 [range: 2-5]. 49 out of the 272 TLs (18%) had received prior radiotherapy, and 38 (14%) had been biopsied. Median progression-free survival (PFS) was 3.8 months. Median OS was 13.4 months. Best overall response per patient was a PR/CR in 22%, stable disease (SD) in 33% and progressive disease (PD) in 45%. Best overall response on 272 TLs was a PR/CR in 52 TLs (19%), SD in 142 TLs (52%) and PD in 78 TLs (29%). DR1 were observed in 8% of patients, whereas DR2 and DR3 were observed in 44% and 10% of patients, respectively. While prior irradiation on TLs did not correlate with the occurrence of DRs, DRs were more common when one TL was biopsied ORa = 2.22 (1.28, 3.86) (p = 0.004).
Conclusions
DR with a responding TL and a progressive TL according to RECIST1.1 was observed in 8% of patients. While prior irradiation on TLs did not correlate with the occurrence of DRs, DRs were more common when one TL was biopsied.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
D. Loirat: Advisory / Consultancy, Travel / Accommodation / Expenses: MSD; Advisory / Consultancy: Novartis; Honoraria (institution), Travel / Accommodation / Expenses: Roche; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy, Travel / Accommodation / Expenses: BMS; Advisory / Consultancy: Pfizer. C. Le Tourneau: Advisory / Consultancy: MSD; Advisory / Consultancy: BMS; Advisory / Consultancy: Amgen; Advisory / Consultancy: Merck; Advisory / Consultancy: Serono; Advisory / Consultancy: Roche; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: Nanobiotix; Advisory / Consultancy: GSK. All other authors have declared no conflicts of interest.
Resources from the same session
5218 - Elevated driver mutational burden or number of perturbed pathways and poor response to abiraterone or enzalutamide in metastatic castration-resistant prostate cancer
Presenter: Bram De Laere
Session: Poster Display session 3
Resources:
Abstract
2452 - High proportion of multiple KRAS mutations in circulating tumor DNA and tumor tissue of pancreatic ductal adenocarcinoma
Presenter: Min Kyeong Kim
Session: Poster Display session 3
Resources:
Abstract
3328 - Biological difference of tumor mutational burden (TMB) and microsatellite instability (MSI) status in patients (pts) with somatic vs. germline BRCA1/2-mutated advanced gastrointestinal (GI) cancers using cell-free DNA (cfDNA) sequencing analysis in the GOZILA study
Presenter: Yasuyuki Kawamoto
Session: Poster Display session 3
Resources:
Abstract
3022 - Cell-Free DNA to Detect Focal Versus Non-Focal MET Amplification in Metastatic Colorectal Cancer Patients: Combined Analysis from Japan and the United States
Presenter: Mishima Saori
Session: Poster Display session 3
Resources:
Abstract
2833 - Presence of circulating tumor DNA in surgically resected renal cell carcinoma is associated with advanced disease and poor patient prognosis
Presenter: Andres Correa
Session: Poster Display session 3
Resources:
Abstract
1376 - Combined genomic and epigenomic assessment of cell-free circulating tumor DNA (cfDNA) for cancer diagnosis and recurrence-risk assessment in early-stage lung cancer
Presenter: Junghee Lee
Session: Poster Display session 3
Resources:
Abstract
4050 - DEMo: a prospective evaluation of a prognostic clinico-molecular composite score in NSCLC patients treated with immunotherapy.
Presenter: Arsela Prelaj
Session: Poster Display session 3
Resources:
Abstract
4727 - Bespoke circulating tumor DNA (ctDNA) analysis as a predictive biomarker in solid tumor patients (pts) treated with single agent pembrolizumab (P)
Presenter: Cindy Yang
Session: Poster Display session 3
Resources:
Abstract
3662 - Dynamic changes in whole-genome cell-free DNA (cfDNA) to identify disease progression prior to imaging in advanced solid tumors
Presenter: Andrew Davis
Session: Poster Display session 3
Resources:
Abstract
3817 - Evaluation of Microsatellite Instability Testing Through cell-free DNA sequencing
Presenter: Shile Zhang
Session: Poster Display session 3
Resources:
Abstract