Abstract 4244
Background
We recently conducted an open- label, single-center, prospective randomized Phase II clinical trial for HLA-A2+ patients with advanced-stage melanoma (NCT01876212) at the University of Pittsburgh Hillman Cancer Center. Patients received ID injections of Type-1-polarized, autologous DC loaded with a mixture of peptides derived from six tumor-associated vascular antigens (DLK1, EPHA2, HBB, NRP1, RGS5, TEM1) combined +/- daily oral administration of dasatinib (70 mg BID) as an immune adjuvant/conditioning agent. Here we report an exploratory analysis of T cell repertoire profiling of longitudinally-sampled peripheral blood leukocytes (PBL) to define potential pharmacodynamic and response biomarkers.
Methods
Total RNA was extracted from pre- and post-treatment PBL from 13 therapy recipients (6 responders, 7 non-Responders) including extended longitudinal samples for four responders. TCRB sequencing was performed via the Oncomine TCRB-LR assay using 25ng total RNA as input. We evaluated T cell clonal expansion and TCR convergence as potential biomarkers of response.
Results
TCR convergence values were elevated in pretreatment PBL of responders compared to non-responders (mean frequency .012 vs .006; p=.01, Wilcoxon), and remained elevated in responders up to 25 weeks post treatment. TCR evenness (normalized Shannon entropy) decreased at week 5 compared to baseline (p=.01, one-sided student’s t-test), indicating increased clonal expansion following treatment.
Conclusions
These data suggest that peripheral blood TCRB convergence may serve as a predictive or prognostic biomarker for response to dendritic cell-based immunotherapy. Our finding of increased T cell clonal expansion at week 5 of treatment supports the notion that TCR sequencing may serve as a tool for the measurement of pharmacodynamic markers of therapeutic agent activity. Ongoing and future studies will further clarify the utility of TCR convergence and clonal expansion as immune repertoire biomarkers.
Clinical trial identification
NCT01876212.
Editorial acknowledgement
Legal entity responsible for the study
University of Pittsburgh School of Medicine & Hillman Cancer Center.
Funding
Thermo Fisher Scientific.
Disclosure
L. Quagliata: Full / Part-time employment: Thermo Fisher Scientific. T. Looney: Full / Part-time employment: Thermo Fisher Scientific. D. Topacio-Hall: Full / Part-time employment: Thermo Fisher Scientific. G. Lowman: Full / Part-time employment: Thermo Fisher Scientific. All other authors have declared no conflicts of interest.
Resources from the same session
3630 - Results of phase 1 clinical trial of high doses of Seleno-L-methionine (SLM) in sequential combination with Axitinib in previously treated and relapsed clear cell renal carcinoma (ccRCC) patients
Presenter: Yousef Zakharia
Session: Poster Display session 3
Resources:
Abstract
2356 - Safety and Efficacy of CDX-014 , an Antibody-Drug Conjugate against T Cell immunoglobulin mucin-1 (TIM-1), in advanced Renal Cell Carcinoma
Presenter: Bradley McGregor
Session: Poster Display session 3
Resources:
Abstract
1028 - SPAZO2 (SOGUG): Outcomes and prognostic significance of IMDC intermediate prognosis subclassification in metastatic renal cell carcinoma (mRCC) in patients treated with 1st-line pazopanib (1stPz).
Presenter: Begona P. Valderrama
Session: Poster Display session 3
Resources:
Abstract
2293 - Effect of Antacid Intake on the Therapeutic Efficacy of Sunitinib (SUN) in Metastatic Renal Cell Carcinoma (mRCC) Patients (pts): a Sub-Analysis of the STAR-TOR Registry
Presenter: Katrin Schlack
Session: Poster Display session 3
Resources:
Abstract
1451 - Randomized phase 3 trial of avelumab + axitinib vs sunitinib as first-line treatment for advanced renal cell carcinoma: JAVELIN Renal 101 Japanese subgroup analysis
Presenter: Motohide Uemura
Session: Poster Display session 3
Resources:
Abstract
4399 - Overall and progression-free survival according to MSKCC scores in 1st line sunitinib treatment of metastatic renal cell carcinoma (mRCC)
Presenter: Jindrich Finek
Session: Poster Display session 3
Resources:
Abstract
1344 - Combination therapy with checkpoint inhibitors for first-line treatment of advanced renal cell carcinoma: A systematic review and meta-analysis of randomized controlled trials
Presenter: Kyaw Thein
Session: Poster Display session 3
Resources:
Abstract
3462 - A phase II trial of TKI induction followed by a randomized comparison between nivolumab or TKI continuation in renal cell carcinoma (NIVOSWITCH)
Presenter: Viktor Grünwald
Session: Poster Display session 3
Resources:
Abstract
5268 - Nivolumab (N) treatment beyond progression in a real-world cohort of patients (pts) with metastatic renal cell carcinoma (mRCC)
Presenter: Sophie Hans
Session: Poster Display session 3
Resources:
Abstract
4235 - First results of safety profile of nivolumab (NIVO) in combination with stereotactic body radiotherapy (SBRT) in II and III line of patients (pts) with metastatic renal cell carcinoma (mRCC) in NIVES Study
Presenter: Cristina Masini
Session: Poster Display session 3
Resources:
Abstract