各位好！今日与大家分享一项针对不可切除NSCLC II期临床试验的ctDNA探索性分析结果。总是在提ctDNA MRD，但临床诊疗策略上究竟该如何应用MRD的结果？临床证据上又有哪些相关研究将会改变诊疗策略。到底ctDNA是一个食之无味弃之可惜的预测标志物？还是能够对诊疗起参考价值的分层方式？？一起来看看。
Analysis of Circulating Tumor DNA Predicts Outcomes of Short Course Consolidation Immunotherapy in Unresectable Stage III Non-Small Cell Lung Cancer
Soyeong Jun, Nikhil A. Shukla, Greg Durm, Angela B. Hui, Sha Cao, Apar Kishor Ganti, Salma K. Jabbour, Christian Kunder, Ash A. Alizadeh, Nasser H. Hanna,Maximilian Diehn
JTO July 04, 2024
INTRODUCTION: The current standard of care for patients with inoperable stage III non-small cell lung cancer (NSCLC) includes chemoradiotherapy (CRT) followed by one year of checkpoint inhibitor (CPI) therapy. However, the optimal duration of consolidation CPI remains unknown. Here, we characterized the relationship between circulating tumor DNA (ctDNA) minimal residual disease (MRD) and clinical outcomes of unresectable locally advanced NSCLC patients treated on a phase 2 trial of short course consolidation immunotherapy after CRT, with the goal of testing if ctDNA may be able to identify patients who do not require a full year of treatment.背景：目前对于无法手术的III期非小细胞肺癌（NHL）患者的标准治疗包括根治性放化疗（CPR）然后进行一年的免疫检查点抑制剂（CPI）治疗。然而，CPI的最佳持续时间仍然未知。本研究描述了循环肿瘤DNA（ctDNA）微小残留病（MRD）与接受放疗后短程巩固免疫治疗II期试验治疗的不可切除的局部晚期非小细胞肺癌患者的临床结果之间的关系，目标是检验ctDNA是否能够识别不需要一整年免疫巩固治疗的患者。
PATIENTS AND METHODS: Plasma samples for ctDNA analysis were collected from patients on the BTCRC LUN 16-081 trial after completion of CRT, prior to C2D1 of CPI (i.e. 1 month after treatment start), and at the end of up to 6 months of treatment. Tumor-informed ctDNA MRD analysis was performed using CAPP-Seq. Levels of ctDNA at each time point were correlated with clinical outcomes.
方法：在完成CPR后、CPI C2 D1之前（即治疗开始后1个月）以及长达6个月的治疗结束时，从BTCRC LU 16-081试验的患者中收集用于ctDNA分析的血浆样本。使用CAPP-Seq进行肿瘤知情的ctDNA MRD分析。每个时间点的ctDNA水平与临床结局进行相关性分析。
RESULTS: Detection of ctDNA predicted significantly inferior progression-free survival (PFS) after completion of CRT (24-month 29% vs 65%, P = 0.0048), prior to C2D1 of CPI (24-month 0% vs 72%, P < 0.0001) and at the end of CPI (24-month 15% vs 67%, P = 0.0011). Additionally, patients with decreasing or undetectable ctDNA levels after one cycle of CPI had improved outcomes compared to patients with increasing ctDNA levels (24-month PFS 72% vs 0%, P < 0.0001). Progression of disease occurred within <12 months of starting CPI in all patients with increasing ctDNA levels at C2D1.
结果：在完成CPR后（24个月29% vs 65%，P = 0.0048）、CPI C2 D1之前（24个月0% vs 72%，P < 0.0001）和CPI结束时（24个月15% vs 67%，P = 0.0011）ctDNA阳性的无进展生存期（PBS）显着较差。此外，与ctDNA水平升高的患者相比，一个周期的CPI后ctDNA水平下降或检测不到的患者的结局有所改善（24个月无生命周期72% vs 0%，P < 0.0001）。在C2 D1时ctDNA水平升高的所有患者中，疾病进展均发生在开始CPI后<12个月内。
CONCLUSION: Detection of ctDNA before, during, or after 6 months of consolidation CPI is strongly associated with inferior outcomes. Our findings suggest that analysis of ctDNA MRD may enable personalizing the duration of consolidation immunotherapy treatment.
结论：在巩固CPI 6个月之前、期间或之后检测ctDNA与不良结果密切相关。我们的研究结果表明，对ctDNA MRD的分析可能能够个性化巩固免疫治疗的持续时间。
1. 老规矩，先来了解下ctDNA相关的具体临床应用场景。推荐大家看这篇来自Charles Swanton团队的综述。目前的ctDNA临床应用更多的是predictive而非prognostic。
10.1016/j.trecan.2024.04.004
2. 其次看研究细节。
①2017年9月18日注册II期临床试验，目的是对比根治性放化疗后的巩固单免（Nivolumab）或免疫联合（Nivolumab+ipilimumab）。设计上是对III期不可切除肺癌的根治性放化疗进行6个月的巩固治疗。两组间18个月PFS无显著性差异。（有一种将降阶治疗的设计理念，即使是文章的生存曲线很早就出现了差异，但并没有让文章更早的发表。）
②转化研究部分重点关注了可获取ctDNA结果的38例患者的172个样本（摘要的结果部分让人感觉在粉饰，introduction部分的最后一句话与研究本身设计不相符合，属于目标与实践不相匹配）。的确很难想象严禁设计的II期研究样本收集也会出现与临床数据间如此大的差异。
③本文文风结构与该团队既往发表在nature cancer的文章类似。在三个时间点（巩固免疫治疗前、巩固治疗1周期后、巩固治疗结束）上，ctDNA阳性患者的PFS较阴性患者差。当然作为斯坦福的主任，该研究PI也知道目前的这个结果是没有把干预措施考虑在内的II期探索性研究。因此斯坦福中心后续开展了辅助治疗领域的ADAPT-E和根治性放化疗后的的ADAPT-C研究。
3.IMpower010、CheckMate816、LCMC3都进行了ctDNA的探索性分析。究竟在真实世界中，哪些场景中ctDNA的临床应用价值最高?如何构建一个基于ctDNA进行治疗决策的诊疗证据？似乎已经成了令无数学者头痛的问题。在这个领域我国是否有必要构建类似PCG研究的大队列？
目录
1. INTRODUCTION
2. METHODS
2.1 Study Design and Patients
2.2 Library preparation and sequencing
2.3 Analysis of sequencing data and Somatic Genotyping
2.4 Detection of ctDNA MRD
2.5 Statistical Analysis
3. Results
3.1 Patient Characteristics and Primary Tumor Analysis (Table 1)(Supplementary Table 1)(Fig. 1A)(Supplementary Table 2)
3.2 Pre-CPI ctDNA analysis (Fig. 1B and Supplementary Table 3)
3.3 ctDNA analysis during consolidation CPI (Fig. 1B)(Fig. 2)(Supplementary Fig. 1A)(Supplementary Table 4)(Fig. 3)
3.4 ctDNA dynamics during consolidation CPI (Fig. 4)
4. Discussion
— 图表汇总—
3.1 Patient Characteristics and Primary Tumor Analysis
Table 1. Patient characteristics.
Supplementary Table 1
Fig. 1A Study schema, clinical characteristics, and tumor genotypes.
(A) Study schematic.
C1D1=prior to cycle 1 day 1; C2D1=prior to cycle 2 day 1; NOS=not otherwise specified; Nivo=Nivolumab; Ipi=Ipilimumab.
Supplementary Table 2
3.2 Pre-CPI ctDNA analysis
Fig. 1B Study schema, clinical characteristics, and tumor genotypes.
(B) Summary of clinical, histopathologic, molecular parameters, and tumor mutations. Mutations in canonical lung cancer driver genes are shown.
(C) Summary of ctDNA detection and clinical progression status.
Supplementary Table 3
3.3 ctDNA analysis during consolidation CPI
Fig. 2 Timelines of treatments, blood draws, and imaging studies.
Swimmer plots showing the timing of consolidation CPI, progression based on RECIST 1.1 evaluation of imaging, and the results of ctDNA analyses for patients with (A) and without progression (B). One patient (B081-1082) died before the first surveillance scan so imaging data were not available.
IT = intrathoracic progression; ET = extrathoracic progression.
Supplementary Fig. 1A
Supplementary Table 4
Fig. 3 ctDNA detection before, during, and after consolidation CPI is associated with clinical outcomes.
(A-C) Cumulative incidence of progression stratified by ctDNA detection after completion of CRT (A), after one cycle of CPI (B), and at the end of the CPI (C). P values were calculated using the Gray test.
(D-F) Kaplan-Meier analysis of progression-free survival stratified by ctDNA detection after completion of CRT (D), after one cycle of CPI (E), and at the end of the CPI (F). P values were calculated using the log-rank test.
(G) Bar plots showing rates of progression in patients with ctDNA detected or not detected pre-consolidation CPI, after one cycle of CPI and at the end of the CPI. The number of patients in each group is displayed on the graph.
(H) Duration of consolidation CPI in patients who were ctDNA negative at the end of therapy and who did not recur.
3.4 ctDNA dynamics during consolidation CPI
Fig. 4 ctDNA concentration changes during consolidation CPI are associated with clinical outcomes.
(A) ctDNA concentration change normalized to pre-treatment ctDNA concentration. The median times for after one cycle of CPI timepoint was 0.92 months and the end of CPI timepoint was 5.47 months after starting consolidation CPI. (n = 33, No progression = 23, Progression = 10). Five patients who had only one time point sample were excluded.
(B) Distribution of ctDNA response patterns after one cycle of consolidation CPI.
(C-E) Cumulative incidence of progression (C), Kaplan-Meier analysis of progression-free survival (D), and overall survival (E) stratified by ctDNA response pattern. P values were calculated using the Gray test (B) or the log-rank test (D, E). Only patients with evaluable pre- and early during CPI are included (n=29). “Decreasing”: ctDNA decreased between the pre-CPI and C2D1 time points. “Increasing”: ctDNA increased between the pre-CPI and C2D1 time points. “Not detected”: ctDNA was not detected pre-CPI.
(F) Bar plots showing proportion of recurrence with the response pattern categories.
(G-H) Longitudinal CT imaging with sum of target lesion longest diameters measured according to RECIST 1.1 (RECIST SLD, right -axis) and ctDNA concentrations (left y-axis) are shown for a patient who had detectable ctDNA prior to consolidation CPI but a decrease early during CPI and did not develop recurrence (G) and for a patient who had detectable ctDNA prior to consolidation CPI but an increase early during CPI and developed recurrence (H).
Nivo = Nivolumab; Ipi = Ipilimumab; ND = not detected; SD = stable disease; PR = partial response; PD = progressive disease; Pleural mets = pleural metastases.
