Abstract 3317
Background
ctDNA allows monitoring of response to therapy and serves as a liquid biopsy for pt selection for targeted therapies. We used samples from pts with NSCLC enrolled in an ongoing phase I/Ib trial (NCT02099058) treated with telisotuzumab vedotin (ABBV-399; teliso-v) alone and in combination with erlotinib or nivolumab to assess the frequency of mutant alleles in ctDNA and the association between ctDNA levels and OR to teliso-v.
Methods
Plasma was collected pre- (C1D1) and post-treatment (≥C2D1) and analyzed using 64-gene PlasmaSELECT™ assay (PGDx). Correlations between ctDNA detection probability and best OR were assessed by Fisher’s exact test; if C2D1 samples were not available, C3D1 (if CR/PR/SD) or FV samples (if PD) were used. The sum of variant allele fraction for all somatic mutations (SumVAF) at C1D1 and C2D1 was compared between response groups and between matched C1D1 and C2D1 samples.
Results
109 pts were analyzed (C1D1 [n = 108]). Among 56 pts without variant alleles detected at C1D1, ctDNA detection probability at ≥C2D1 was similar regardless of response (P = 0.51). For 52 pts with ctDNA detectable at C1D1, ctDNA detection probability at ≥C2D1 was higher for SD/PD (85%) vs CR/PR (55%), but not significant (P = 0.15). For all response groups SumVAF decreased from C1D1 to C2D1, suggesting a pharmacodynamic effect of teliso-v. SumVAF was significantly lower in pts with CR/PR vs SD/PD at C1D1 (P = 0.015) and marginally lower at C2D1 (P = 0.097).Table:
1469P Pre- and post-treatment mean (stdev) sum of variant allele fraction by response category
CR/PR n = 24 | SD n = 58 | PD n = 27 | P§ (FC) of SumVAF: SD/PD vs CR/PR | |
---|---|---|---|---|
Pre-treatment (C1D1) n = 108* | 3% (6%) | 8% (15%) | 6% (15%) | 0.015 (2.88) |
Post-treatment (C2D1) n = 83† | 1% (5%) | 4% (7%) | 3% (9%) | 0.097 (2.87) |
P‡, C1D1 vs C2D1 Mean decrease of SumVAF from C1D1 to C2D1 | 0.01 2% | 0.04 3% | 0.02 4% |
C1D1 data, missing for 1 patient with SD.
†C2D1 data, missing for 26 patients (4 CR/PR, 11 SD, and 11 PD).
‡By pair-wise t-test on 82 patients with both C1D1 and C2D1 data available.
§By 2-group t-test.
C, cycle; CR, complete response; D, day; FC, fold change; PD, progressive disease; PR, partial response; SD, stable disease; stdev, standard deviation; SumVAF, sum of variant allele fraction for all somatic mutations.
Conclusions
Baseline SumVAF levels and ctDNA detection probability at ≥C2D1 were lower with CR/PR vs SD/PD in pts with detectable ctDNA at C1D1. SumVAF decreased by C2D1 regardless of response, with more consistent reduction in pts with CR/PR. These data may suggest that discrete patterns of change in SumVAF over time correlate with OR outcome. Further investigation is warranted to assess ctDNA’s predictive value.
Clinical trial identification
NCT02099058.
Editorial acknowledgement
Iratxe Abarrategui, PhD, CMPP, from Aptitude Health, The Hague, Netherlands; funded by AbbVie.
Legal entity responsible for the study
AbbVie Inc.
Funding
AbbVie Inc.
Disclosure
R.S. Heist: Advisory / Consultancy: Apollomics; Advisory / Consultancy: Boehringer Ingelheim; Advisory / Consultancy, Research grant / Funding (institution): Novartis; Advisory / Consultancy: Tarveda Therapeutics; Research grant / Funding (institution): AbbVie; Research grant / Funding (institution): Celgene; Research grant / Funding (institution): Roche; Research grant / Funding (institution): Incyte; Research grant / Funding (institution): Mirati Therapeutics; Research grant / Funding (institution): Peregrine Pharmaceuticals; Research grant / Funding (institution): Exelixis; Research grant / Funding (institution): Millennium; Research grant / Funding (institution): Debiopharm Group; Research grant / Funding (institution): Corvus Pharmeceuticals; Research grant / Funding (institution): Daiichi Sankyo; Research grant / Funding (institution): Agios; Research grant / Funding (institution): Pfizer. M. Motwani: Shareholder / Stockholder / Stock options, Full / Part-time employment: AbbVie. L. Naumovski: Shareholder / Stockholder / Stock options, Full / Part-time employment: AbbVie. J. Wu: Shareholder / Stockholder / Stock options, Full / Part-time employment: AbbVie. B.A. Bach: Shareholder / Stockholder / Stock options, Full / Part-time employment: AbbVie. X. Lu: Shareholder / Stockholder / Stock options, Full / Part-time employment: AbbVie. K. Kelly: Advisory / Consultancy, Travel / Accommodation / Expenses: AstraZeneca; Advisory / Consultancy, Travel / Accommodation / Expenses: Genentech/Roche; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Regeneron; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: AbbVie; Advisory / Consultancy: Janssen; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: EMD Serono; Honoraria (self), Advisory / Consultancy: Merck; Advisory / Consultancy: Pfizer; Licensing / Royalties, web information resource : UpToDate; Research grant / Funding (institution): Genentech; Research grant / Funding (institution): Celgene; Research grant / Funding (institution): Five Prime Therapeutics; Research grant / Funding (institution): Transgene; Research grant / Funding (institution): Lycera.
Resources from the same session
5595 - Is there any prognostic significance in pleural involvement and/or effusion (Ple-I/E) in patients with ALK-positive NSCLC?
Presenter: Saadettin Kilickap
Session: Poster Display session 1
Resources:
Abstract
5840 - Crizotinib in patients with advanced or metastatic ROS1-rearranged lung cancer (EUCROSS): A European phase 2 clinical trial – Updated progression-free survival, overall survival and mechanisms of resistance
Presenter: Sebastian Michels
Session: Poster Display session 1
Resources:
Abstract
1905 - NTRK1-3 Genomic Fusions in Non-Small Cell Lung Cancer (NSCLC) Determined by Comprehensive Genomic Profiling
Presenter: Sai-Hong Ou
Session: Poster Display session 1
Resources:
Abstract
3016 - Preferential expression of the affected MET allele in lung carcinomas with heterozygous MET exon 14 skipping mutations: implications for clinical testing
Presenter: Evgeny Imyanitov
Session: Poster Display session 1
Resources:
Abstract
4120 - Brain metastases, treatment patterns and outcomes in ROS1-positive NSCLC patients from US oncology community centers
Presenter: Matthew G Krebs
Session: Poster Display session 1
Resources:
Abstract
3764 - Patients with metastatic non-small cell lung cancer and targetable molecular alterations in Germany. Treatment and first outcome data from the prospective German Registry Platform CRISP (AIO-TRK-0315)
Presenter: Frank Griesinger
Session: Poster Display session 1
Resources:
Abstract
4070 - Crizotinib vs Platinum-based Chemotherapy as First-line Treatment for Advanced Non-small Cell Lung Cancer with Different ROS1 Fusion Variants
Presenter: Haiyan Xu
Session: Poster Display session 1
Resources:
Abstract
5528 - Genomic and clinical characterization of Non-small cell lung cancer (NSCLC) patients harboring mutations in FGFR2 and FGFR3
Presenter: Matthias Scheffler
Session: Poster Display session 1
Resources:
Abstract
3779 - The expression of HER2-gene polymorphisms -1985G>T and P1170A C>G and their association with the risk of development of lung adenocarcinoma
Presenter: Ivan Aleric
Session: Poster Display session 1
Resources:
Abstract
3020 - Circulating tumor DNA (ctDNA) analysis depicts mechanisms of resistance and tumor response to BRAF inhibitors in BRAF-mutant non-small cell lung cancer (NSCLC)
Presenter: Sandra Ortiz - Cuaran
Session: Poster Display session 1
Resources:
Abstract