Abstract 1133
Background
Immune checkpoint inhibitors are an important therapy. However, their essence is nonspecific and efficiency of single usage is not satisfactory. The mutant neoantigen specific T (Nas-T) cell, as an adoptive cell treatment, is a specific immunotherapy for each individual. Our previous research has proved that the combined immunotherapy of mutant Nas-T cell and PD1 antibody is more effective than PD1 alone in prolonging PFS (World Conference on Lung Cancer 2018). We aim to evaluate the characteristics of the immune repertoire (IR) as a predictive biomarker for immunotherapy and to construct personalized and specific TCR-T.
Methods
14 patients with advanced solid tumors who failed after multiline treatments were recruited. They were divided into durable clinical benefit (complete response, partial response or stable disease for more than 3 months) and non-durable clinical benefit (DCB and NCB) based on PFS. Peripheral blood was collected at baseline and each cycle. IR-seq of the CDR3 regions of human TCRβ chains was used to interrogate the TCRs frequency. We used single neoantigen to stimulate the infused T cells and performed RNAseq for the sorted CD137(+) cells to obtain the full-length TCR α and β chain. Lastly, we constructed TCR-T cells via transfecting the TCR α/β pair into the T cells of patients and co-cultured with neoantigen to analyze the functionality of TCRs.
Results
After neoantigen pulsing, the clonality of infused T cells pool significantly increased (P = 0.0001), suggesting some tumor-specific T-cells were expanded and enriched after neoantigen pulsing. Compared to baseline, T-cell repertoire of NCB and DCB after 1st cycle displayed significant changes: Shannon 1.19 vs 0.97 (P = 0.002); clonality 0.68 vs 1.19 (P = 0.001). Elevated clonality may indicate expanded tumor-specific T-cells which could recognize mutant neoantigen specifically. Besides, based on the in vitro TCR-T experiments, the constructed TCR-T cells can specifically recognize the mutant neoantigen and lyse the target cells expressing the corresponding neoantigen.Table:
1228P
Neoantigen Sequence | HLA-I typing | TCR Vα | TCR Vβ | |||
---|---|---|---|---|---|---|
Gene name | Sequence* | All V Hits With Score# | Clonal Sequence# | All V Hits With Score# | Clonal Sequence# | |
MTAP/SPINK1 Fused Gene | VLLPRHMKV | A0201 | TRAV35 (574.6) | TGTGCTGGGTATGGCTCTAGCAA CACAGGCAAACTAATCTTT | TRBV19 (646.8) | TGTGCCAGTCGGACAGGGGGA TCACCCCTCCACTTT |
FER | NYVSNVSKF | A2301 | TRAV29DV5 (667.6) | TGTGCAGCTTCAACTGGGGCAAA CAACCTCTTCTTT | TRBV7-2 (626.7) | TGTGCCAGCACCTCTGCCCCC TCCTACGAGCAGTACTTC |
SPINK1 | FLLSALALL | B4403 | TRAV20 (589.1) | TGTGCTGTTCCCCTGGGAACAGG CTTTCAGAAACTTGTATTT (response to neoantigen) | TRBV21-1 (557.8) | TGTGCCAGCAGCAAAGACCCT AGCGGGAATCAAGAGACCCAGTACTTC |
CLCN6 | ALIGAAASL | B6701 | TRAV19 (612.4) | TGTGCTCTTCTGAATTATGGTGGTGC TACAAACAAGCTCATCTTT | TRBV6-5 (675.4) | TGTGCCAGCAGTGGGACAGCCAATGA GCAGTTCTTC (response to neoantigen) |
MTAP | AESFMFRTW | C0401 | TRAV38-2DV8 (658.4) | TGTGCTTATTGGGAGCTTGTCTCTGGGG CTGGGAGTTACCAACTCACTTTC | TRBV5-1 (637.6) | TGCGCCAGCAGCTTGACTAGCGGGGGG TTCTACGAGCAGTACTTC |
TAP1 | RLSLFLALV | C0702 | TRAV16 (622.2) | TGTGCTCCCTGGGCCCTAGGAGGAGG TGCTGACGGACTCACCTTT | TRBV30 (403.4) | TGTGCCTGGAGTGTAACAGGGGGC AAAGCAGATACGCAGTATTTT |
MAN2C1 | FLQGRNFFL |
Conclusions
The mutant Nas-T cell is a personalized immunotherapy. IR is a potential predictive biomarker.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Shunchang Jiao.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4596 - A Phase 2, Open-Label, Randomized, Multicenter Trial of Encorafenib + Binimetinib Evaluating a Standard-dose and a High-dose Regimen in Patients With BRAFV600-Mutant Melanoma Brain Metastasis (MBM) (POLARIS)
Presenter: Michael Davies
Session: Poster Display session 3
Resources:
Abstract
1891 - Continuation of annual screening mammograms and breast-cancer mortality in women over 70
Presenter: Xabier Garcia De Albeniz
Session: Poster Display session 3
Resources:
Abstract
5587 - Introducing standardized medical procedure and dynamic decision support program in precision oncology for the community of practice
Presenter: Istvan Petak
Session: Poster Display session 3
Resources:
Abstract
4757 - Effectively using primary care givers in oncology care through capacity building, task sharing and techno-mentoring.
Presenter: Dinesh Pendharkar
Session: Poster Display session 3
Resources:
Abstract
4497 - A single institution review of capecitabine related acute admissions and cost analysis
Presenter: Gemma Dart
Session: Poster Display session 3
Resources:
Abstract
2187 - Health status of middle-aged and older cancer survivors in China: results from the China Health and Retirement Longitudinal Study (CHARLS)
Presenter: Jiarui Li
Session: Poster Display session 3
Resources:
Abstract
5101 - Crossed looks on lung cancer perception and knowledge from general public and physicians in France: results of a two-fold survey
Presenter: Céline Mascaux
Session: Poster Display session 3
Resources:
Abstract
4354 - Knowledge and perception of clinical trials (CTs) and attitude towards participation among Polish oncological patients - A pilot survey
Presenter: Artur Kotowski
Session: Poster Display session 3
Resources:
Abstract
3499 - Achieving best possible cancer treatment outcomes in care pathways through benchmarking; ABC-Benchmarking
Presenter: Anke Wind
Session: Poster Display session 3
Resources:
Abstract
2270 - Impact of 10-day Fulbright Specialist Program (FSP) and Project Pink Blue (PPB) Education Sessions on Medical Oncology knowledge among Doctors that treat cancer in Nigeria
Presenter: Mike Martin
Session: Poster Display session 3
Resources:
Abstract