Circulating Tumor DNA-Guided De-Escalation Targeted Therapy for Advanced Non-Small Cell Lung Cancer: A Nonrandomized Clinical Trial.

Importance: Uninterrupted targeted therapy until disease progression or intolerable toxic effects is currently the routine therapy for advanced non-small cell lung cancer (NSCLC) involving driver gene variations. However, drug resistance is inevitable. Objective: To assess the clinical feasibility of adaptive de-escalation tyrosine kinase inhibitor (TKI) treatment guided by circulating tumor DNA (ctDNA) for achieving complete remission after local consolidative therapy (LCT) in patients with advanced NSCLC. Design, Setting, and Participants: This prospective nonrandomized trial was conducted at a single center from June 3, 2020, to July 19, 2022, and included 60 patients with advanced NSCLC with driver variations without radiologically detectable disease after TKI and LCT. The median (range) follow-up time was 19.2 (3.8-29.7) months. Data analysis was conducted from December 15, 2022, to May 10, 2023. Intervention: Cessation of TKI treatment and follow-up every 3 months. Treatment was restarted in patients with progressive disease (defined by the Response Evaluation Criteria in Solid Tumors 1.1 criteria), detectable ctDNA, or elevated carcinoembryonic antigen (CEA) levels, whichever manifested first, and treatment ceased if all indicators were negative during follow-up surveillance. Main Outcomes and Measures: Progression-free survival (PFS). Secondary end points were objective response rate, time to next treatment, and overall survival. Results: Among the total study sample of 60 participants (median [range] age, 55 [21-75] years; 33 [55%] were female), the median PFS was 18.4 (95% CI, 12.6-24.2) months and the median (range) total treatment break duration was 9.1 (1.5-28.1) months. Fourteen patients (group A) remained in TKI cessation with a median (range) treatment break duration of 20.3 (6.8-28.1) months; 31 patients (group B) received retreatment owing to detectable ctDNA and/or CEA and had a median PFS of 20.2 (95% CI, 12.9-27.4) months with a median (range) total treatment break duration of 8.8 (1.5-20.6) months; and 15 patients (group C) who underwent retreatment with TKIs due to progressive disease had a median PFS of 5.5 (95% CI, 1.5-7.2) months. For all participants, the TKI retreatment response rate was 96%, the median time to next treatment was 29.3 (95% CI, 25.3-35.2) months, and the data for overall survival were immature. Conclusions and Relevance: The findings of this nonrandomized trial suggest that this adaptive de-escalation TKI strategy for patients with NSCLC is feasible in those with no lesions after LCT and a negative ctDNA test result. This might provide a de-escalation treatment strategy guided by ctDNA for the subset of patients with advanced NSCLC. Trial Registration: ClinicalTrials.gov Identifier: NCT03046316.

PD-L1 expression guidance on sintilimab versus pembrolizumab with or without platinum-doublet chemotherapy in untreated patients with advanced non-small cell lung cancer (CTONG1901): A phase 2, randomized, controlled trial.

No direct comparison has been performed between different programmed cell death-1 (PD-1) inhibitors for first-line treatment in patients with advanced non-small cell lung cancer (NSCLC). The feasibility of using PD-L1-expression-guided immunotherapy remains unknown. In this open-label, phase 2 study (NCT04252365), patients with advanced NSCLC without EGFR or ALK alterations were randomized (1:1) to receive sintilimab or pembrolizumab monotherapy (PD-L1 expression ≥ 50%), or sintilimab or pembrolizumab plus platinum-based chemotherapy (PD-L1 expression < 50%). The sample size was calculated by optimal two-stage design. The primary endpoint was the objective response rate (ORR). The study included 71 patients (sintilimab arms, n = 35; pembrolizumab arms, n = 36) and met its primary endpoint, with a confirmed ORR of 51.4% (18/35) in the sintilimab arms. The confirmed ORR (95% confidence interval) was 46.2% (19.2%, 74.9%) and 42.9% (17.7%, 71.1%) for patients treated with sintilimab and pembrolizumab monotherapy; and 54.5% (32.2%, 75.6%) and 45.4% (24.4%, 67.8%) for those treated with sintilimab- and pembrolizumab-based combination therapies. The median progression-free survival was 6.9 versus 8.1 months for all sintilimab-treated versus all pembrolizumab-treated patients, respectively, in which it was 7.6 versus 11.0 months in monotherapy and 7.4 versus 7.1 months in combination therapies. The median overall survival was 14.9 versus 21.3 months for all sintilimab-treated versus all pembrolizumab-treated patients, respectively, in which it was 14.9 versus 22.6 months in monotherapy and 14.7 versus 17.3 months in combination therapies. Treatment-related adverse events were consistent with safety outcomes of monotherapy and combination therapy in previous phase III studies. However, the incidence of rash was higher with sintilimab than pembrolizumab monotherapy. This is the first prospective phase 2 study to directly compare two anti-PD-1 antibodies as first-line treatment in advanced NSCLC. Sintilimab was efficacious and well-tolerated irrespective of PD-L1 expression level in patients with advanced NSCLC and had similar efficacy and safety to pembrolizumab.

First-line pyrotinib in advanced HER2-mutant non-small-cell lung cancer: a patient-centric phase 2 trial.

To explore targeted treatment options in patients with non-small-cell lung cancer (NSCLC) with rare genetic mutations in the context of a patient-centric clinical trial, we initiated, in parallel, a phase 2 adaptive umbrella trial consisting of a criteria-fulfilled (CF) cohort and a compassionate use (CU) cohort under expanded eligibility criteria, and a prospective real-world study (RWS). Here, we present efficacy and safety data from 48 patients with treatment-naive, advanced HER2-mutant NSCLC treated with the pan-HER receptor tyrosine kinase inhibitor pyrotinib (CF and CU cohorts) or physician's therapy of choice (RWS cohort). In the phase 2 trial CF cohort (n = 28), the primary endpoint was reached with an objective response rate of 35.7% after pyrotinib treatment. Secondary endpoints included disease control rate (89.3%), median progression-free survival (PFS) (7.3 months), median overall survival (OS) (14.3 months) and toxicity, which was acceptable, with grade 3 or 4 treatment-related adverse events occurring in three patients (10.7%). The phase 2 trial CU cohort (n = 12) showed an objective response rate of 16.7%, disease control rate of 83.4%, median PFS of 4.7 months and median OS of 14.2 months after pyrotinib treatment. The RWS cohort (n = 8) had no responses to physician's therapy of choice, while median PFS and OS were 3.0 and 12.2 months, respectively. Phase 2 umbrella trial, clinicaltrials.gov identifier: NCT03574402 . RWS, clinicaltrials.gov identifier: NCT03605602 .

Genomic and immune characteristics of HER2-mutated non-small-cell lung cancer and response to immune checkpoint inhibitor-based therapy.

The efficacy of immunotherapy in advanced HER2-mutated non-small-cell lung cancer (NSCLC) remains incomprehensively studied. A total of 107 NSCLC patients with de novo HER2 mutations were retrospectively studied at Guangdong Lung Cancer Institute [GLCI cohort, exon 20 insertions (ex20ins): 71.0%] to compare clinical/molecular features and immune checkpoint inhibitor (ICI)-based therapy efficacy between patients with ex20ins and non-ex20ins. Two external cohorts (TCGA, n = 21; META-ICI, n = 30) were used for validation. In the GLCI cohort, 68.2% of patients displayed programmed death-ligand 1 (PD-L1) expression < 1%. Compared with ex20ins patients, non-ex20ins patients had more concurrent mutations in the GLCI cohort (P < 0.01) and a higher tumour mutation burden in the TCGA cohort (P = 0.03). Under ICI-based therapy, advanced NSCLC patients with non-ex20ins had potentially superior progression-free survival [median: 13.0 vs. 3.6 months, adjusted hazard ratio (HR): 0.31, 95% confidence interval (CI): 0.11-0.83] and overall survival (median: 27.5 vs. 8.1 months, adjusted HR: 0.39, 95% CI: 0.13-1.18) to ex20ins patients, consistent with findings in the META-ICI cohort. ICI-based therapy may serve as an option for advanced HER2-mutated NSCLC, with potentially better efficacy in non-ex20ins patients. Further investigations are warranted in clinical practice.

Intratumoral genetic and immune microenvironmental heterogeneity in T4N0M0 (diameter ≥ 7 cm) non-small cell lung cancers.

BACKGROUND: Starting with low metastatic capability, T4N0M0 (diameter ≥ 7 cm) non-small cell lung cancers (NSCLCs) constitute a unique tumor subset, as with a large tumor size but no regional or distant metastases. We systematically investigated intratumoral heterogeneity, clonal structure, chromosomal instability (CIN), and immune microenvironment in T4N0M0 (≥7 cm) NSCLCs. METHODS: Whole-exome sequencing, RNA sequencing, and multiplex immunohistochemistry (mIHC) staining were conducted to analyze 24 spatially segregated tumor samples from eight patients who were pathologically diagnosed with T4N0M0 (diameter ≥ 7 cm) NSCLCs. The adjacent normal tissues and peripheral blood served as controls. RESULTS: In total, 35.2% of mutations and 91.1% of somatic copy number alterations were classified as subclonal events, which exhibited widespread genetic intratumoral heterogeneity. In contrast, a low degree of CIN was observed. None of the patients had genome doubling. The burden of loss of heterozygosity, aneuploidy, and the genome instability index of these tumors were significantly lower than those in the TRACERx cohort. Expression profiles revealed significantly upregulated expression of cell division-related signals and the G2/M checkpoint pathway. In addition, a similar expression pattern of the immune microenvironment was observed in different regions of the tumor, which was confirmed by mIHC profiles. CONCLUSIONS: Our study indicates the presence of intratumoral genetic heterogeneity and immune microenvironmental heterogeneity features in T4N0M0 NSCLCs, and the low degree of CIN may be related to the low metastatic capability.

Genetic Profiling of Cell-Free DNA From Pleural Effusion in Advanced Lung Cancer as a Surrogate for Tumor Tissue and Revealed Additional Clinical Actionable Targets.

BACKGROUND: Pleural effusion (PE) has been one of the promising sources of liquid biopsy in advanced lung cancer patients. However, its clinical utility is not widely accepted due to the lack of full estimation of its potential versus routine clinical samples. METHOD: A total of 164 advanced lung cancer patients were enrolled with 164 matched tumor tissue and PE-cfDNA, 153 accompanied plasma and 63 1PE-sDNA. RESULT: PE-cfDNA displayed significantly higher median mutant allele frequency and an overall mutation concordance rate of 65% to tissue, which was higher than PE-sDNA (43%) and plasma-cfDNA (43%). The discrepancies between PE-cfDNA and tumor tissue were high in several genes, including SMARCA4, PIK3CA, ERBB2, KM T2A, ALK and NF1. For clinically actionable mutations, the concordance rate between PE-cfDNA and tumor tissue is 87%. Eleven patients were identified with actionable mutations in PE-cfDNA and four patients benefited from PE-cfDNA-guided targeted. Meanwhile, PE-cfDNA recapitulated mutations of diverse tissue origins and provided more mutational information under the circumstance that tumor tissue or tumor tissue of different origins were unavailable. The combination of tumor tissue and PE-cfDNA profiling increased positive detection rates of patients compared to tumor tissue alone. Our finding highlighted the importance of PE-cfDNA in the optimal selection of patients for targeted therapy. CONCLUSION: The PE-cfDNA-based liquid biopsy displays better performance in the characterization of gene alterations than PE-sDNA and plasma-cfDNA. PE-cfDNA together with tumor tissue profiling optimizes comprehensively genomic profiling of lung cancer patients, which might be important for selecting patients for better treatment management.

EGFR L792H and G796R: Two Novel Mutations Mediating Resistance to the Third-Generation EGFR Tyrosine Kinase Inhibitor Osimertinib.

BACKGROUND: The third-generation EGFR tyrosine kinase inhibitor osimertinib has been approved in many countries to treat advanced NSCLC in patients with the EGFR T790M mutation. As the development of acquired resistance is inevitable, it is urgent that the mechanisms of such resistance be clarified. METHODS: DNA samples from a cohort of 340 patients with lung adenocarcinoma who were taking osimertinib were subjected to next-generation sequencing and screened in terms of the frequencies of the L792H and G796R mutations. Ba/F3 cells stably expressing the EGFR L858R/T790M mutations (in cis) with either the L792H or G796R mutation were created to investigate the impact of the two novel mutations on EGFR tyrosine kinase inhibitors and other potential drug combinations in vitro. Structural analyses were performed by using Schrödinger/Maestro software (version 11.1.012, Schrödinger LLC, Cambridge, MA). RESULTS: L792H and G796R were detected in 1.76% (six of 340) and 0.56% (two of 340) patients with lung adenocarcinoma treated with osimertinib, respectively. The introduction of L792H or G796R mutations against an L858R/T790M background caused dramatic reductions in osimertinib sensitivity. Structural modeling showed that mutations in cis with T790M either forced the ligand (osimertinib) to rotate out (breaking the binding) or pulled the hinge loop (breaking the hinge). Various other drug combinations. including cetuximab with EAI045, failed to inhibit either cis mutant effectively. CONCLUSIONS: The EGFR L858R/T790M/L792H and L858R/T790M/G796R mutations conferred resistance to osimertinib both in vitro and in silico. For patients in whom the two resistance mutations occur at low frequency, more precise treatment strategies and additional combinational approaches are required.

A comprehensive review of uncommon EGFR mutations in patients with non-small cell lung cancer.

INTRODUCTION: Patients with non-small cell lung cancer (NSCLC) harboring uncommon epidermal growth factor receptor (EGFR) mutations are a heterogeneous group exhibiting differential responses to EGFR inhibitors. This retrospective study reviews the prevalence of uncommon EGFR mutations in a Chinese NSCLC cohort and the clinical characteristics and efficacy of EGFR tyrosine kinase inhibitors (TKIs) associated with these patients. MATERIALS ANDMETHODS: A total of 5363 lung cancer patients were screened and underwent EGFR genotyping at the Guangdong Lung Cancer Institute. Of those with uncommon EGFR mutations, the clinical characteristics and responses to EGFR-TKIs were reviewed retrospectively. RESULTS: Uncommon EGFR mutations were observed in 218 patients, comprising 11.9% of all patients with documented EGFR mutations. More smokers (30.7% vs. 24.3%, P=0.039) and males (54.1% vs. 44.4%, P=0.007) were among the patients with uncommon mutations compared with common mutations. The most frequent uncommon mutations were exon 20 insertions (30.7%, n=67), followed by G719X mutations (21.1%, n=46) and compound L858R mutations (17.0%, n=37). Favorable efficacy was observed in patients harboring compound L858R or G719X mutations, with a median progression-free survival (PFS) of 15.2 (95% CI: 8.7-21.7) or 11.6 (95% CI: 3.6-19.6) months, respectively. The median PFS of those with the T790M mutation or an exon 20 insertion was 1.0 (95% CI: 0.0-2.2) and 3.0 (95% CI: 1.3-4.7) months, respectively. CONCLUSION: This study reviewed the prevalence of uncommon EGFR mutations and their sensitivity to EGFR-TKIs. Favorable responses were observed in patients with G719X and compound L858R mutations, indicating that they may benefit from EGFR-TKIs as a first-line therapy.

A Higher Proportion of the EGFR T790M Mutation May Contribute to the Better Survival of Patients with Exon 19 Deletions Compared with Those with L858R.

INTRODUCTION: Increasing evidence has demonstrated that exon 19 deletions (Del19) and L858R mutation in EGFR have different prognostic and predictive roles in NSCLC. We aimed to investigate whether these two mutations produced differences in mechanisms of resistance to EGFR tyrosine kinase inhibitors. METHODS: Consecutive patients with advanced EGFR-mutant NSCLC who acquired resistance to EGFR tyrosine kinase inhibitors and underwent postprogression biopsy were enrolled. Mechanisms including T790M mutation, mesenchymal-epithelial transition proto-oncogene (MET) amplification, and histological transformation, as well as KRAS, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha gene (PIK3CA) mutation, and anaplastic lymphoma receptor tyrosine kinase gene (ALK) fusion, were analyzed. RESULTS: The prevalence of T790M mutation was significantly higher in the Del19 subgroup than that in L858R subgroup (50.4% versus 36.5%, p = 0.043). Apart from this, there was no difference in other mechanisms including MET amplification and histological transformation. The median overall survival (OS) of patients with T790M mutation was 36.0 months (95% confidence interval [CI]: 30.9-41.2), which was significantly longer than the 26.5 months (95% CI: 24.0-29.0) in MET-positive patients, 19.7 months (95% CI: 18.2-21.2) in patients with histological transformation, and 23.0 months (95% CI: 17.4-28.6) in the KRAS/PIK3CA/ALK-altered population (p = 0.021). The hazard ratios of the MET-amplification subgroup and subgroup with histological transformation were 1.809-fold and 2.370-fold higher than that in T790M-positive subgroup. The median OS times were months 33.3 (95% CI: 28.9-37.7) in the Del19 subgroup and 26.4 months (95% CI: 23.2-29.6) in the L858R subgroup (p = 0.028). However, in multivariable analysis adjusted for T790M genotype, the EGFR mutation subtype was no longer found to be significant. CONCLUSIONS: Significant OS benefit was observed in patients with T790M mutation, suggesting that a larger proportion of T790M mutation might contribute to the better survival of patients with Del19.

EGFR as a Pharmacological Target in EGFR-Mutant Non-Small-Cell Lung Cancer: Where Do We Stand Now?

Targeting the epidermal growth factor receptor (EGFR) using tyrosine kinase inhibitors (TKIs) is highly effective in terms of tumor response rate, survival, and quality of life. However, acquired resistance to EGFR-TKIs is inevitable. Ongoing clinical trials will provide evidence for optimal strategies for patients with EGFR mutant non-small-cell lung cancer (NSCLC) in the near future. Numerous new agents are specifically addressing resistance mechanisms; mature data are related to the T790M mutation and MET pathway activation. Here, we provide a comprehensive review of new perspectives on how to optimize the management of this molecular disease.

Afatinib in the first-line treatment of epidermal-growth-factor-receptor mutation-positive non-small cell lung cancer: a review of the clinical evidence.

First-line afatinib significantly improved progression-free survival, patient-reported outcomes, and quality of life compared with chemotherapy regimens in patients with advanced epidermal-growth-factor-receptor (EGFR) mutation-positive non-small cell lung cancer, based on results of the LUX-Lung 3 and LUX-Lung 6 trials. When the analysis of these trials was restricted to patients with common EGFR mutations only (exon 19 deletions and L858R), the advantage over chemotherapy was even more pronounced. A significant overall survival advantage was firstly demonstrated versus chemotherapy in patients with non-small cell lung cancer-harboring EGFR exon 19 deletion (del19) mutations. First-line afatinib was also effective in patients with certain uncommon EGFR mutation and patients with central nervous system metastasis. So far, these data are not sufficient to conclude that afatinib is better than first-generation EGFR inhibitors. In addition, the toxicity profile of afatinib was somewhat worse than that observed with either erlotinib or gefitinib. In the absence of direct comparisons, for each patient the choice among the available EGFR inhibitors should take into account all the clinically relevant endpoints, including disease control, survival prolongation, tolerability, and quality of life.

Distribution and prognosis of uncommon metastases from non-small cell lung cancer.

BACKGROUND: According to the literature and our experience, the most common sites of non-small cell lung cancer (NSCLC) metastases include the brain, bone, liver, adrenal glands, contralateral lung and distant lymph nodes. Metastases to other organs are relatively rare. There have been numerous case reports and a few small case series of uncommon metastases derived from NSCLC. METHODS: We defined all organs except the common metastatic sites mentioned above as uncommon sites of metastasis. Patients with uncommon metastases among 2,872 consecutive NSCLC patients with stage IV disease at the Guangdong Lung Cancer Institute (GLCI) from 2006 to 2012 were included in this study. The diagnosis of uncommon metastases was based on pathology or imaging studies. RESULTS: Uncommon metastases were diagnosed in 193 cases at anatomical sites such as the soft tissue, kidney, pancreas, spleen, peritoneum, intestine, bone marrow, eye, ovary, thyroid, heart, breast, tonsil and nasal cavity. Uncommon metastases were identified as independent poor prognostic factors through a multivariate analysis with a HR (hazard ratio) of 1.29 [95% confidence interval (CI) 1.09-1.52, P < 0.01]. Those patients who received systemic therapy plus local treatment had a better survival rate than did those who received systemic therapy only (P < 0.01); all patients received best supportive care. CONCLUSIONS: Metastases to the above mentioned sites are infrequent. The presentation of uncommon metastases tends to indicate a poor outcome, and selected patients may benefit from local treatment.

Emerging paradigms in targeted treatments for Asian patients with NSCLC.

INTRODUCTION: EGFR-targeted drugs have been successfully approved in many countries and have demonstrated higher efficacy and lower toxicity than chemotherapy in molecularly defined subgroups of patients. Significant advances in clinical trials and studies focusing on targeted therapies have rapidly developed in Asia. AREAS COVERED: In the present review article, all of the published data or meeting abstracts on completed or ongoing trials of targeted treatment for Asian patients with NSCLC were collected and analyzed. EXPERT OPINION: Routine molecular testing has been used clinically to identify mutations/fusions and guide patient selection for targeted therapies. Based on the evidence presented, we provided up-to-date treatment recommendations for Asian patients with advanced NSCLC. Future directions, including dividing Del19 and L858R patients into two distinct populations, will optimize therapeutic strategies for L858R patients and may inform rational trial design by considering the proportion of type of sensitive EGFR mutation as a stratification factor. Another important aspect to consider involves how to monitor resistance to TKIs, which will improve the outcome for lung cancer patients with driver gene mutations.