Abstract 4836
Background
Lung cancer patients with activating EGFR mutations tend to respond poorly to IO, but this is not true for all activating mutation driven lung cancers. Recent data show that patients with BRAF mutations tend to respond better to IO. Our study estimated the tumor neoantigen burden in these tumors, and the likelihood of their presentation to cytotoxic T cells by estimating their binding affinity to major histocompatibility complex (MHC).
Methods
Whole exome data for 68 patients with EGFR mutant lung adenocarcinoma and 33 with BRAF mutations were extracted from the Cancer Genome Atlas. MAFTOOLs was used to determine the tumor mutational load. Nonamers were estimated by simulating possible nonamer neoantigens from MAF files. The neoantigen (MT) and wildtype (WT) binding affinities to MHC-I were calculated using the NetMHC 4.0 server. The differential binding affinity of the neoantigens in comparison to wildtype was calculated as mean differential agretopicity index (DAI) = WT - MT. Patient survival was estimated by the Kaplan-Meier method.
Results
Patients with mutated BRAF had higher median mutational burden (445, range 165-776) than those with EGFR mutations (90.5, range 60.5-219.5, p = 0.001). The median number of simulated neoantigens was higher in the BRAF (9536.5, range 3839.5-14626.0) vs the EGFR group (1895.5, range 1148.5-4766.5, p < 0.001). Mean DAI for BRAF and EGFR patients were 1046 and 1033, respectively, p = 0.86. In the BRAF mutant group, patients with DAI < 1,000 had significantly better 5-year survival (80% vs 40%, p = 0.022) compared to patients with DAI > 1,000. No such survival benefit was identified in the EGFR mutant group (56% vs 58%, p = 0.81).
Conclusions
BRAF mutant lung cancers are characterized by higher neoantigen burden, but their neoantigen differential binding affinity to MHC-I complex was not different from EGFR mutant lung cancers. Our analysis suggests that the improved response to IO in the BRAF mutant population is due to increased quantity in neoantigen burden and not a qualitative difference in MHC-I binding. Further, DAI had a prognostic impact in the BRAF population suggesting that it may be a measure of tumor neoantigen immunogenicity.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
J. Subramanian: Advisory / Consultancy, Speaker Bureau / Expert testimony: AstraZeneca; Advisory / Consultancy: Pfizer; Advisory / Consultancy, Speaker Bureau / Expert testimony: Boehringer Ingelheim; Advisory / Consultancy, Research grant / Funding (institution): Paradigm; Speaker Bureau / Expert testimony: Lilly; Research grant / Funding (institution): Biocept. All other authors have declared no conflicts of interest.
Resources from the same session
5389 - Two-weekly accelerated BEP (aBEP) regimen as induction chemotherapy (CT) in intermediate and poor prognosis patients (pts) with nonseminomatous germ cell tumors (NSGCT): final results of phase II trial.
Presenter: Alexey Tryakin
Session: Poster Display session 3
Resources:
Abstract
2934 - Differential expression of circulating miR375 and miR371 to detect teratoma and viable germ cell malignancy
Presenter: Lucia Nappi
Session: Poster Display session 3
Resources:
Abstract
3585 - Prognosis of anaemia in disseminated testicular germ cell tumours. On behalf of the Spanish Germ Cell Cancer Group (SGCCG)
Presenter: Esmeralda Garcia Torralba
Session: Poster Display session 3
Resources:
Abstract
2254 - The Effects Of Primary Testicular Tumor Localization On Prognosis In Patients With Nonseminomatous Testis Cancer
Presenter: Birol Yildiz
Session: Poster Display session 3
Resources:
Abstract
4505 - Initial Results of a Phase II study of Nivolumab and Ipilimumab in Metastatic Adrenal Tumors.
Presenter: Matthew Campbell
Session: Poster Display session 3
Resources:
Abstract
3369 - NEMIO: a randomized phase II trial evaluating efficacy and safety of dose dense MVAC (ddMVAC) + durvalumab +/- tremelimumab as neoadjuvant treatment in patients with bladder muscle-invasive urothelial carcinoma
Presenter: Constance Thibault
Session: Poster Display session 3
Resources:
Abstract
2075 - KEYNOTE-866: Phase 3 Study of Perioperative Pembrolizumab (pembro) or Placebo (pbo) in Combination With Neoadjuvant Chemotherapy in Cisplatin (cis)-Eligible Patients (pts) With Muscle-Invasive Bladder Cancer (MIBC)
Presenter: Arlene Siefker-Radtke
Session: Poster Display session 3
Resources:
Abstract
4824 - KEYNOTE-905: A Phase 3 Study of Cystectomy Plus Perioperative Pembrolizumab Versus Cystectomy Alone in Cisplatin (cis)-Ineligible Patients (pts) With Muscle-Invasive Bladder Cancer (MIBC)
Presenter: Matthew Galsky
Session: Poster Display session 3
Resources:
Abstract
2253 - Phase 3 LEAP-011 trial: First-Line Pembrolizumab With Lenvatinib in Patients With Advanced Urothelial Carcinoma Ineligible to Receive Platinum-Based Chemotherapy
Presenter: Yohann Loriot
Session: Poster Display session 3
Resources:
Abstract
4310 - PULSE : A Single Arm Trial Assessing The Activity and Safety of Avelumab Immunotherapy Maintenance among Patients With Locally Advanced or Metastatic Squamous Cell Penile Carcinoma (mSCPC).
Presenter: Noemie Gassian
Session: Poster Display session 3
Resources:
Abstract