Abstract 2996
Background
Myeloid derived suppresor cells (MDSC) are a heterogeneous population of immature myeloid cells that inhibits antitumor responses by T lymphocytes. High levels of MDSC have been found in the tumor microenvironment, which is correlated with a poor prognosis of the disease. Our purposes are to evaluate the objective response rate (ORR) to test the treatment efficacy and to show the decrease of MDSC in clinical benefit (CB) patients, that includes complete response (CR), partial response (PR) and stabilization of disease (SD), when compared with progression of disease (PD).
Methods
58 patients diagnosed of R/R DLBCL who were not high dose chemotherapy and autologous bone narrow transplantation candidates were recruited from Spanish hospitals. The patients progressed to a prior R-CHOP therapy and had ECOG ≤ 1. They were treated with the R2-GDP chemotherapy schedule (rituximab, lenalidomide, gemcitabine, dexamethasone and cisplatin). Three peripheral blood analysis were carried out: basal, cycle 3 (C3) and end of induction (EI) by flow cytometry to determine the MDSC level.
Results
30 patients obtained CB response to treatment (PR 11 patients, CR 14 patients and SD 5 patients) and 28 patients obtained PD. A remarkable decrease of MDSC is shown in the Table, except in PD patients. On the other hand, ORR was 69% at C3 (PR 53%+ CR 16%) and 66% at EI (PR 40% + CR 26%).Table:
1267P MDSC levels (cells/uL) in CB (CR, PR, SD) and PD. Av: average; St: Standard Deviation; *: Statistically significant differences (P < 0.05) compared with basal
Response | Basal Av (St) | C3 Av (St) | EI Av (St) |
---|---|---|---|
CB | 19.9 (4.0) | 10.0 (3.1) | 4.8 (2.1)* |
CR | 18.6 (4.9) | 12.4 (3.7) | 2.7 (1.1)* |
PR | 13.0 (3.2) | 4.5 (0.8) | 1.4 (0.5)* |
SD | 35.3 (14.8) | 18.8 (11.6) | 18.5 (9.2) |
PD | 10.7 (4.0) | 8.6 (2.4) | 12.2 (2.9) |
Conclusions
The ORR obtained shown the treatment efficacy in R/R DLBCL to stimulate the immune system antitumor response, which explains the decrease of MDSC in all CB groups and a non-important increase in PD patients. Based on these results, MDSC seem to be an important therapeutic target against tumor progression, as well as being a potentially promising marker of response.
Clinical trial identification
EudraCT number: 2014-001620-29.
Editorial acknowledgement
Legal entity responsible for the study
Grupo Español para el Tratamiento y Estudio de los Linfomas (GOTEL).
Funding
Grupo Español para el Tratamiento y Estudio de los Linfomas (GOTEL).
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3839 - Fenofibrate impairs pro-tumorigenic potential of cancer stem cell-like cells within drug-resistant prostate cancer cell populations.
Presenter: Tomasz Wróbel
Session: Poster Display session 3
Resources:
Abstract
3842 - Effect of docetaxel-resistance on the reactivity of prostate cancer cells to metformin
Presenter: Jessica Catapano
Session: Poster Display session 3
Resources:
Abstract
5198 - Cell plasticity and taxanes resistance in metastatic prostate cancer: ESRP1 as a predictive biomarker of taxane response
Presenter: Natalia Jimenez
Session: Poster Display session 3
Resources:
Abstract
2981 - Effect of Selumetinib plus AZD8186 treatment on Cabazitaxel sensitivity in docetaxel-acquired resistant metastatic prostate cancer cell lines
Presenter: Vicenc Ruiz de Porras
Session: Poster Display session 3
Resources:
Abstract
2779 - Anti-tumor activity of cediranib, a pan-inhibitor of vascular endothelial growth factor receptors, in pancreatic ductal adenocarcinoma cells
Presenter: Majid Momeny
Session: Poster Display session 3
Resources:
Abstract
1782 - The molecular mechanisms of EpCAM in regulating tumor progression and development of anti-EpCAM antibodies for colon cancer diagnosis and therapy
Presenter: Han-chung Wu
Session: Poster Display session 3
Resources:
Abstract
1322 - Detection of microRNAs as biomarker for anti-EGFR antibody resistance in colon cancer patients
Presenter: Jens Hahne
Session: Poster Display session 3
Resources:
Abstract
1579 - Serum exosomal microRNA-199b-5p as a novel circulating biomarker to predict response of preoperative chemoradiotherapy for locally advanced rectal cancer
Presenter: Dong Won Baek
Session: Poster Display session 3
Resources:
Abstract
1761 - Live biobank of patient-derived organoids from Thai colorectal cancer patients enables clinical outcome prediction
Presenter: Pariyada Tanjak
Session: Poster Display session 3
Resources:
Abstract
3542 - The biological implications of PDCD6 dysregulation in colorectal cancer
Presenter: Romina Briffa
Session: Poster Display session 3
Resources:
Abstract