Abstract 4900
Background
Diffuse large B-cell lymphoma (DLBCL) is heterogenous morphologically, clinically and genetically. Although half of patients could be cured by frontline R-CHOP, approximately 10%-15% are refractory or relapse within the 1st year. Here, we investigated the molecular landscapes of patients with diverse responses to R-CHOP.
Methods
Targeted sequencing was performed on baseline samples of 105 DLBCL patients. After a median follow-up of 67 months, 63 (60.0%) patients had refractory or relapsed disease. All patients received R-CHOP(-like) regimen as the first-line treatment. After excluding double-hit and primary central system lymphoma, 81 patients with measurable disease before initial treatment and followed over 1 year were included for survival analysis. Patients who received less than a partial remission in the first-line setting or those relapsed within the first 12 months since the initiation of the treatment were defined as having primary refractory.
Results
Collectively, we identified 1162 mutations spanning 103 genes from this cohort. The most commonly seen mutations included PIM1(33%), MYD88 (29%), BCL2 (29%), TP53 (29%), CD79B (25%) and KMT2D (24%). Patients with TP53 mutations were more likely to have primary refractory disease (41.7% vs 7.4%, p = 0.002). For those with TP53 disruptive mutations, primary refractory is also more common (22.9% vs. 0%, p = 0.006). Interestingly, BCL-2 somatic hypermutation (SHM) was only seen in patients without primary refractory disease (p = 0.014). The International prognostic index (IPI) score and other clinical characteristics were comparable between the 2 groups. Furthermore, TP53 mutations were correlated with shorter PFS (p = 0.001) and OS (p = 0.049). Next, we investigated mutation landscape in patients with WT TP53 (n = 58) and found that patients harboring MYD88 L265P had significantly inferior PFS than those with WT or non-265P (p = 0.046).
Conclusions
We revealed that patients with TP53 mutation are more likely to have primary refractory to standard R-CHOP. This study also showed the prognostic potential of MYD88 L265P in those with WT TP53 and indicated that distinct subgroups could be identified by TP53 and MYD88 L265P mutations.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4370 - Continental differences in pathologic response with neoadjuvant ipilimumab (IPI) plus nivolumab (NIVO) in patients with macroscopic stage III melanoma in the phase 2 OpACIN-neo trial.
Presenter: Irene Reijers
Session: Poster Display session 3
Resources:
Abstract
3230 - Comparable responses of melanoma at primary site and synchronous lymph node metastases upon neoadjuvant ipilimumab (IPI) and nivolumab (NIVO)
Presenter: Judith Versluis
Session: Poster Display session 3
Resources:
Abstract
3171 - Adjuvant Therapies for Stage III Melanoma: Benchmarks for Bringing Clinical Trials to Clinical Practice
Presenter: Tina HIEKEN
Session: Poster Display session 3
Resources:
Abstract
3493 - Mixture-cure modeling for resected stage III/IV melanoma in the phase 3 CheckMate 238 trial
Presenter: Jeffrey Weber
Session: Poster Display session 3
Resources:
Abstract
3036 - An open-label, non-randomized, phase IIIb study of trametinib in combination with dabrafenib for patients with unresectable advanced BRAFV600-mutant melanoma: a subgroup analysis of patients with brain metastasis
Presenter: Caroline Dutriaux
Session: Poster Display session 3
Resources:
Abstract
2233 - Adverse event (AE) kinetics in patients (pts) treated with dabrafenib + trametinib (D + T) in the metastatic and adjuvant setting
Presenter: Jean Jacques Grob
Session: Poster Display session 3
Resources:
Abstract
2435 - A Single Arm, Open Label, Phase II, Multicenter Study to Assess the Detection of the BRAF V600 Mutation on cfDNA from Plasma in Patients with Advanced Melanoma
Presenter: Piotr Rutkowski
Session: Poster Display session 3
Resources:
Abstract
1766 - Efficacy and Safety of Dabrafenib and Trametinib in Patients with Metastatic BRAFV600 Mutation-positive Melanoma in the Real-World Setting – Interim results of the non-interventional COMBI-r study
Presenter: Carola Berking
Session: Poster Display session 3
Resources:
Abstract
2131 - Trial update: A randomized Phase Ib/II study of the selective small molecule Axl inhibitor Bemcentinib (BGB324) in combination with either dabrafenib/trametinib (D/T) or pembrolizumab in patients with metastatic melanoma
Presenter: Oddbjørn Straume
Session: Poster Display session 3
Resources:
Abstract
4074 - Analysis of pyrexia in patients (pts) treated with dabrafenib (D) and/or trametinib (T) across clinical trials
Presenter: Caroline Robert
Session: Poster Display session 3
Resources:
Abstract