Preclinical study and phase II trial of adapting low-dose radiotherapy to immunotherapy in small cell lung cancer.

BACKGROUND: Immune checkpoint inhibitors (ICIs) provide modest but unsatisfactory benefits for extensive-stage small cell lung cancer (ES-SCLC). Developing strategies for treating ES-SCLC is critical. METHODS: We preliminarily explored the outcomes of salvage low-dose radiotherapy (LDRT) plus ICI on refractory SCLC patients. Next, we evaluated the combinational efficacy in murine SCLC. The tumor immune microenvironment (TIME) was analyzed for mechanistic study. Subsequently, we conducted a multicenter, prospective phase II trial that administered concurrent thoracic LDRT plus chemoimmunotherapy to treatment-naive ES-SCLC patients (MATCH trial, NCT04622228). The primary endpoint was confirmed objective response rate (ORR), and the key secondary endpoints included progression-free survival (PFS) and safety. FINDINGS: Fifteen refractory SCLC patients treated with LDRT plus ICI were retrospectively reviewed. The ORR was 73.3% (95% confidence interval [CI], 44.9-92.2). We identified a specific dose of LDRT (15 Gy/5 fractions) that exhibited growth retardation and improved survival in murine SCLC when combined with ICIs. This combination recruited a special T cell population, TCF1+ PD-1+ CD8+ stem-like T cells, from tumor-draining lymph nodes into the TIME. The MATCH trial showed a confirmed ORR of 87.5% (95% CI, 75.9-94.8). The median PFS was 6.9 months (95% CI, 5.4-9.3). CONCLUSIONS: These findings verified that LDRT plus chemoimmunotherapy was safe, feasible, and effective for ES-SCLC, warranting further investigation. FUNDING: This research was funded by West China Hospital (no. ZYJC21003), the National Natural Science Foundation of China (no. 82073336), and the MATCH trial was fully funded by Roche (China) Holding Ltd. (RCHL) and Shanghai Roche Pharmaceuticals Ltd. (SRPL).

Immunotherapy for patients with advanced non-small cell lung cancer harboring oncogenic driver alterations other than EGFR: a multicenter real-world analysis.

Background: The administration of immune checkpoint inhibitors (ICIs) in advanced non-small cell lung cancer (NSCLC) with oncogenic driver alterations other than epidermal growth factor receptor (EGFR) aroused a heated discussion. We thus aimed to evaluate ICI treatment in these patients in real-world routine clinical practice. Methods: A multicenter, retrospective study was conducted for NSCLC patients with at least one gene alteration (KRAS, HER2, BRAF, MET, RET, ALK, ROS1) receiving ICI monotherapy or combination treatment. The data regarding clinicopathologic characteristics, clinical efficacy, and safety were investigated. Results: A total of 216 patients were included, the median age was 60 years, 72.7% of patients were male, and 46.8% had a smoking history. The molecular alterations involved KRAS (n=95), HER2 (n=42), BRAF (n=22), MET (n=21), RET (n=14), ALK (n=14), and ROS1 (n=8); 56.5% of patients received immunotherapy in the first-line, and the rest 43.5% were treated as a second-line and above. For the entire cohort who received immunotherapy-based regimens in the first-line, the median progression-free survival (PFS) was 7.5 months and the median overall survival (OS) was 24.8 months. For the entire cohort who received immunotherapy-based regimens in the second-line and above, the median PFS was 4.7 months and median OS was 17.1 months. KRAS mutated NSCLC treated with immunotherapy-based regimens in the first-line setting had a median PFS and OS were 7.8 and 26.1 months, respectively. Moreover, the median PFS and OS of immunotherapy-based regimens for KRAS-mutant NSCLC that progressed after chemotherapy were 5.9 and 17.1 months. Programmed death ligand 1 (PD-L1) expression level was not consistently associated with response to immunotherapy across different gene alteration subsets. In the KRAS group, PD-L1 positivity [tumor proportion score (TPS) ≥1%] was associated with better PFS and OS according to the multivariate Cox analysis. No statistically significant association was found for smoking status, age, or gender with clinical efficacy in any gene group analyses. Conclusions: KRAS-mutant NSCLC could obtain clinical benefits from ICIs either for treatment-naive patients or those who have experienced progression after chemotherapy, and PD-L1 positive expression (TPS >1%) may be a potential positive predictor. For NSCLC with ALK, RET and ROS1 rearrangement, MET exon 14 skipping mutation, or BRAF V600E mutation, effectiveness of single or combined ICI therapy remains limited, therefore, targeted therapies should be considered prior to immunotherapy regimens. Future studies should address the investigation of better predictive biomarkers for immunotherapy response in oncogene-driven NSCLC.

First-line treatment of driver gene-negative metastatic lung adenocarcinoma with malignant pleural effusion: Should chemotherapy be combined with an immune checkpoint inhibitor or bevacizumab?

Patients with metastatic lung adenocarcinoma (MLA) and malignant pleural effusion (MPE) without driver gene mutations have a poor prognosis. None of the standard treatment strategies is recommended for such patients. We retrospectively analyzed the efficacy of the first-line treatment for this specific population: standard platinum-based doublet chemotherapy (CT), CT plus an immune checkpoint inhibitor (CT plus ICI), and CT plus bevacizumab (CT plus Bev). A total of 323 eligible patients were enrolled: CT alone (n = 166), CT plus Bev (n = 72), and CT plus ICI (n = 85). Treatment efficacy assessments were performed every two cycles according to the RECIST guidelines. The endpoints were overall survival (OS) and progression-free survival (PFS). Kaplan-Meier (K‒M) curves and the log-rank test were used to compare OS and PFS. p < 0.05 was the threshold of significance (statistical software: SPSS). The median follow-up was 11.4 months (range, 2.1-49.6 months). PFS and OS in the CT plus ICI/CT plus Bev cohort were significantly longer than those in the CT group (PFS: 7.8/6.4/3.9 months, p < 0.0001; OS: 16.4/15.6/9.6 months, p < 0.0001, respectively). CT plus Bev had better PFS and OS than CT plus ICI/CT in PD-L1 < 1% patients (PFS: 8.4/5.0/3.8 months, p < 0.0001; OS: 15.6/12.9/9.3 months, p < 0.0001). Among patients with PD-L1 1-49%, CT plus ICI led to a longer PFS and OS (PFS: 8.9/5.8/4.2 months, p = 0.009; OS: 24.2/18.8/11.5 months, p = 0.03). In the cohort with PD-L1 ≥ 50%, CT plus ICI was still the best first-line treatment (PFS: 19.7/13.8/9.6 months, p = 0.033; OS: 27.2/19.6/14.9 months, p = 0.047). In driver gene-negative MLA with MPE, CT plus Bev or ICI better controlled MPE and significantly prolonged survival compared to CT alone. PD-L1 expression (negative/positive) may be a key factor influencing the choice of CT plus Bev or ICI.

Updated overall survival and circulating tumor DNA analysis of ensartinib for crizotinib-refractory ALK-positive NSCLC from a phase II study.

BACKGROUND: The initial phase II stuty (NCT03215693) demonstrated that ensartinib has shown clinical activity in patients with advanced crizotinib-refractory, anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC). Herein, we reported the updated data on overall survival (OS) and molecular profiling from the initial phase II study. METHODS: In this study, 180 patients received 225 mg of ensartinib orally once daily until disease progression, death or withdrawal. OS was estimated by Kaplan‒Meier methods with two-sided 95% confidence intervals (CIs). Next-generation sequencing was employed to explore prognostic biomarkers based on plasma samples collected at baseline and after initiating ensartinib. Circulating tumor DNA (ctDNA) was detected to dynamically monitor the genomic alternations during treatment and indicate the existence of molecular residual disease, facilitating improvement of clinical management. RESULTS: At the data cut-off date (August 31, 2022), with a median follow-up time of 53.2 months, 97 of 180 (53.9%) patients had died. The median OS was 42.8 months (95% CI: 29.3-53.2 months). A total of 333 plasma samples from 168 patients were included for ctDNA analysis. An inferior OS correlated significantly with baseline ALK or tumor protein 53 (TP53) mutation. In addition, patients with concurrent TP53 mutations had shorter OS than those without concurrent TP53 mutations. High ctDNA levels evaluated by variant allele frequency (VAF) and haploid genome equivalents per milliliter of plasma (hGE/mL) at baseline were associated with poor OS. Additionally, patients with ctDNA clearance at 6 weeks and slow ascent growth had dramatically longer OS than those with ctDNA residual and fast ascent growth, respectively. Furthermore, patients who had a lower tumor burden, as evaluated by the diameter of target lesions, had a longer OS. Multivariate Cox regression analysis further uncovered the independent prognostic values of bone metastases, higher hGE, and elevated ALK mutation abundance at 6 weeks. CONCLUSION: Ensartinib led to a favorable OS in patients with advanced, crizotinib-resistant, and ALK-positive NSCLC. Quantification of ctDNA levels also provided valuable prognostic information for risk stratification.

Involved-field irradiation or elective-nodal irradiation in neoadjuvant chemo-radiotherapy for locally-advanced esophageal cancer: comprehensive analysis for dosimetry, treatment-related complications, impact on lymphocyte, patterns of failure and survival.

Purpose: To compare the differences between involved-field irradiation (IFI) and elective nodal irradiation (ENI) in selecting the optimal target area for neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC). Materials and methods: We retrospectively analyzed 267 patients with LA-ESCC, of whom 165 underwent ENI and 102 underwent IFI. Dosimetry, treatment-related complications, pathological responses, recurrence/metastasis patterns, and survival were compared between the two groups. Results: The median follow-up duration was 27.9 months. The R0 resection rates in the IFI and ENI groups were 95.1% and 92.7%, respectively (p=0.441), while the pathological complete response (pCR) rates were 42.2% and 34.5%, respectively (p=0.12). The ENI group received higher radiation doses to the heart (HV30:23.9% vs. 18%, p=0.033) and lungs (LV30:7.7% vs. 4.9%, p<0.001) than the IFI group. Consequently, the ENI group showed a higher incidence of grade 2 or higher radiation pneumonitis (30.3% vs. 17.6%, p=0.004) and pericardial effusion (26.7% vs. 11.8%, p=0.021) than the IFI group. Post-operation fistulas were observed in 3 (2.9%) and 17 cases (10.3%) in the IFI and ENI groups, respectively (p=0.026). In the multivariate analysis, smoking, positive lymph node involvement (pN+), and anastomotic fistula were independent predictors of overall survival (OS). The pN+ patients exhibited a greater propensity for recurrence compared to pN- patients, especially in the first year of follow-up (6.67% vs. 0.56%, p=0.003). Conclusion: The ENI group had a higher incidence of radiation-induced adverse events compared to the IFI group, likely due to the higher radiation doses to normal tissues. Considering the similar disease-free survival (DFS) and OS rates in the two groups, IFI may be suitable for nCRT in patients with LA-ESCC, although further prospective studies are warranted.

The quality and clinical translation of radiomics studies based on MRI for predicting Ki-67 levels in patients with breast cancer.

OBJECTIVE: To evaluate the methodological quality of radiomics literature predicting Ki-67 levels based on MRI in patients with breast cancer (BC) and to propose suggestions for clinical translation. METHODS: In this review, we searched PubMed, Embase, and Web of Science for studies published on radiomics in patients with BC. We evaluated the methodological quality of the studies using the Radiomics Quality Score (RQS). The Cochrane Collaboration's software (RevMan 5.4), Meta-DiSc (v. 1.4) and IBM SPSS (v. 26.0) were used for all statistical analyses. RESULTS: Eighteen studies met our inclusion criteria, and the average RQS was 10.17 (standard deviation [SD]: 3.54). None of these studies incorporated any of the following items: a phantom study on all scanners, cut-off analyses, prospective study, cost-effectiveness analysis, or open science and data. In the meta-analysis, it showed apparent diffusion coefficient (ADC) played a better role to predict Ki-67 level than dynamic contrast-enhanced (DCE) MRI in the radiomics, with the pooled area under the curve (AUC) of 0.969. CONCLUSION: Ki-67 index is a common tumor biomarker with high clinical value. Radiomics is an ever-growing quantitative data-mining method helping predict tumor biomarkers from medical images. However, the quality of the reviewed studies evaluated by the RQS was not so satisfactory and there are ample opportunities for improvement. Open science and data, external validation, phantom study, publicly open radiomics database and standardization in the radiomics practice are what researchers should pay more attention to in the future. ADVANCES IN KNOWLEDGE: The RQS tool considered the radiomics used to predict the Ki-67 level was of poor quality. ADC performed better than DCE in radiomic prediction. We propose some measures to facilitate the clinical translation of radiomics.

Safety and Tolerability of Low-Dose Radiation and Stereotactic Body Radiotherapy + Sintilimab for Treatment-Naïve Stage IV PD-L1+ Non-Small Cell Lung Cancer Patients.

PURPOSE: Low-dose radiotherapy (LDRT) may enhance the synergistic antitumor effect of combined immunotherapy and stereotactic body radiotherapy (SBRT). The safety and efficacy of this novel triple-combination therapy were evaluated for the first time as first-line treatment for patients with metastatic non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: This prospective phase I study enrolled 29 patients and included a dose-escalation and dose-expansion phase. Patients received SBRT [30 Gray (Gy)/3f] to small lesions and LDRT (2 Gy/1f, 4 Gy/2f, or 10 Gy/5f) to a large lesion concurrently, followed by sintilimab (a programmed death-1 inhibitor). The primary endpoint was safety and tolerability; secondary endpoints included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). RESULTS: No dose-limiting toxicities were observed during the dose-escalation phase; 4 Gy/2f was the recommended LDRT dose. Median follow-up was 15.6 months. Treatment-related adverse events (TRAE) occurred in 96.6% (28/29) of patients [grade ≥ 3; 20.7% (6/29)]; 2 patients (6.9%) discontinued due to TRAEs. Seven patients experienced pneumonitis (grade 2, n = 6; grade 3, n = 1). Immune-related adverse events were noted in 58.6% (17/29) of patients. In patients with tumor assessment (n = 28), ORR and confirmed ORR were 60.7% and 57.1%, respectively. Median PFS was 8.6 months (95% confidence interval, 3.7-16.5), and median OS was not reached. Exploratory analyses suggested both expanded and newly emerging T-cell receptor clonotypes were associated with better PFS. CONCLUSIONS: The findings indicate that the novel SBRT + LDRT + sintilimab therapy is safe and promising in patients with programmed death ligand-1-positive, driver gene-negative primary metastatic NSCLC.

Pericardial irradiation dose may be strongly associated with grade 4 lymphopenia and affect prognosis in patients with locally advanced esophageal cancer receiving definitive concurrent chemoradiotherapy.

BACKGROUND: The immune system may influence prognosis, and lymphopenia is a frequent side effect of concurrent chemoradiotherapy (CCRT). Radical irradiation for locally advanced esophageal cancer (LA-EC) exposes significant vascular and heart volumes. In this study, we hypothesized that lymphopenia is linked to cardiac and pericardial doses and affects patient prognosis. METHODS AND MATERIALS: We identified 190 LA-EC patients who received radical CCRT. Multivariate analysis (MVA) was performed to correlate clinical factors and dosimetric parameters with overall survival (OS). We collected lymphocyte-related variables and ratios before and during CCRT. MVA was performed to correlate hematologic toxicity with OS. The relationship between dosimetric parameters and G4 lymphopenia was determined using logistic stepwise regression. Finally, a nomogram of G4 lymphopenia was developed and validated externally. RESULTS: Median follow-up time for all patients was 27.5 months. On MVA for OS, higher pericardial V30 (PV30 ) was linked to worse survival (HR: 1.013, 95% CI: 1.001-1.026, p = 0.039). The median OS stratified by PV30 > 55.3% and PV30 ≤ 55.3% was 24.0 months and 54.0 months, respectively (p = 0.004). G4 lymphopenia was shown to be linked with worse OS in the MVA of hematological toxicity with OS (HR: 2.042, 95% CI: 1.335-3.126, p = 0.001). Thirty of the 100 patients in the training set had G4 lymphopenia. Logistic stepwise regression was used to identify variables associated with G4 lymphopenia, and the final model consisted of stage-IVA (p = 0.017), platelet-to-lymphocyte ratio during CCRT (p = 0.008), Heart V50 (p = 0.046), and PV30 (p = 0.048). Finally, a nomogram predicting G4 lymphocytopenia were constructed and externally validated. The ROC curve showed an AUC for internal validation of 0.775 and external validation of 0.843. CONCLUSION: Higher doses of pericardial radiation might affect LA-EC patients' prognosis by inducing G4 lymphopenia during CCRT. Further prospective studies are warranted to confirm these findings, especially in the era of immune-checkpoint inhibitor treatment.

Optimal timing of hypofractionated stereotactic radiotherapy for epidermal growth factor receptor-mutated non-small-cell lung cancer patients with brain metastases.

BACKGROUND: For epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) patients with limited brain metastases (BMs), who eventually receive both tyrosine kinase inhibitors (TKIs) treatment and brain radiotherapy, the optimal timing of radiotherapy is not clear. The present retrospective analysis aimed to partly solve this problem. METHODS: In total 84 EGFR-mutated NSCLC patients with limited BMs, who received both TKI treatment and brain hypofractionated stereotactic radiotherapy (HSRT), were enrolled. Patients were divided into three groups based on whether the HSRT was administrated 2 weeks before or after the beginning of TKI treatment (upfront HSRT), when intracranial lesions stabilized after TKI treatment (consolidative HSRT), or when the intracranial disease progressed after TKI treatment (salvage HSRT). The clinical efficacy and toxicities were evaluated. RESULTS: The median intracranial progression-free survival (iPFS) and overall PFS calculated from the initiation of HSRT (iPFS1 and PFS1) of all patients were 17.5 and 13.1 months, respectively. The median iPFS and PFS calculated from the initiation of TKI treatment (iPFS2 and PFS2) of all patients were 24.1 and 18.4 months, respectively. Compared to consolidative and salvage HSRT, upfront HSRT improved iPFS1 (not reached vs. 17.5 months vs. 11.0 months, p < 0.001) and PFS1 (18.4 months vs. 9.1 months vs. 7.9 months, p < 0.001), and reduced the initial intracranial failure rate (12.5% vs. 48.1% vs. 56%, p < 0.001). However, there were no significant differences between the three groups for iPFS2, PFS2, and overall survival. Hepatic metastases and diagnosis-specific Graded Prognostic Assessment (ds-GPA) at 2-3 were poor prognostic factors. CONCLUSION: For patients who receive both TKI treatment and brain HSRT, the timing of HSRT does not seem to influence the eventual therapeutic effect. Further validation in prospective clinical studies is needed.

Real-world clinical analysis in 190 advanced NSCLC patients with uncommon EGFR mutations: A multi-center study.

Differently from epidermal growth factor receptor (EGFR) 19Del and L858R mutations, the panoramic description of uncommon EGFR mutations is far from mature. Our understanding of its population characteristics, treatment response, and drug resistance mechanisms needs urgent expansion and deepening. Our study enrolled 437 patients with non-small-cell lung cancer from four clinical centers and who had uncommon EGFR mutations. The clinical characteristics of all patients and the treatment outcomes of 190 advanced patients who received pharmacotherapy were analyzed. Moreover, the acquired resistance mechanisms were explored based on 53 tissue or liquid re-biopsy data in 45 patients. Patients with EGFR 20ins had a shorter survival time compared with patients with non-20ins mutations. In total, 149 cases had received EGFR-tyrosine kinase inhibitors (TKI); afatinib was significantly superior to other EGFR-TKIs both in ORR and mPFS in all uncommon mutations and especially in the L861Q group. The most common acquired drug resistance mechanism was MET amplification, followed by EGFR T790M, which was significantly different from common EGFR mutations.

The safety of combining immune checkpoint inhibitors and platinum-based chemotherapy for the treatment of solid tumors: A systematic review and network meta-analysis.

Objective: Combination treatment regimens consisting of both immune checkpoint inhibitors (ICI) and chemotherapeutic agents have emerged as the standard of care for a range of cancers. This network meta-analysis (NMA) examined the toxicity profiles and safety rankings of these different ICI-based combination regimens. Methods: The PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for all randomized controlled trials (RCTs) published as of March 1, 2022 comparing two or more treatment regimens in which at least one arm was comprised of an ICI + platinum-based chemotherapeutic regimen. Treatment-related adverse events (AEs) of any grade and AEs of grade 3 or higher were the primary endpoints for this analysis, while specific AE types were secondary endpoints. This NMA combined both direct and indirect comparisons when analyzing odds ratios (ORs) and the surface under the cumulative ranking curve (SUCRA) for different ICI-based treatment regimens. Results: In total, 33 RCTs enrolling 19,012 cancer patients were included in this NMA. Of the analyzed regimens, avelumab + chemotherapy and camrelizumab + chemotherapy were associated with a significantly greater risk of AEs of any grade relative to ipilimumab + chemotherapy, durvalumab + chemotherapy, or pembrolizumab + chemotherapy. No significant differences in the risk of AEs of grade 3 or higher were observed when comparing different ICI regimens. Hepatotoxicity and pyrexia were the most common AEs associated with atezolizumab + chemotherapy treatment. Ipilimumab + chemotherapy was associated with a relatively higher risk of gastrointestinal and skin toxicity. Skin toxicity and hypothyroidism were the major AEs associated with nivolumab + chemotherapy. Fatigue and pneumonia were the most common AEs respectively associated with sugemalimab + chemotherapy and pembrolizumab + chemotherapy regimens. Conclusions: Of the evaluated regimens, camrelizumab + chemotherapy and avelumab + chemotherapy were associated with significantly higher rates of AEs of any grade, whereas durvalumab and sintilimab were relatively safe PD-L1 and PD-1 inhibitors, respectively, when administered in combination with platinum-based chemotherapy. However, none of the evaluated ICI + chemotherapy regimens exhibited any differences with respect to the incidence of grade 3 or higher AEs, offering guidance that may be of value in routine clinical practice.

Survival of Patients With Inoperable Non-Small Cell Lung Cancer With Baseline Severe Pulmonary Dysfunction: Impacts of Thoracic Radiotherapy and Predictive Analysis for Acute Radiation Pneumonitis.

BACKGROUND AND PURPOSE: Currently, there is no standard treatment for patients with lung cancer with deteriorated pulmonary function. In this study, we aimed to assess the efficacy of thoracic radiotherapy for unresectable non-small cell lung cancer (NSCLC) with baseline severe pulmonary dysfunction and severe acute radiation pneumonitis (SARP). METHODS: Patients were categorized into a radiotherapy group and a nonradiotherapy group, followed by analysis of clinical variables. A Cox regression was used to evaluate the impact of various factors on overall survival (OS). Each SARP factor's predictive value was assessed using logistic regression, receiver operating characteristic curve, and Kaplan-Meier analyses. RESULTS: The median OS in the radiotherapy group was 21.6 months vs 8.9 months in the nonradiotherapy group. Cox analysis revealed that chemotherapy (HR, 0.221; 95% CI, 0.149-0.329; P < .001) and radiotherapy (HR, 0.589; 95% CI, 0.399-0.869; P = .008) are independent prognostic factors for the current cohort. The data suggested that the ipsilateral lung V10 (ilV10, the percentage of the lung volume that received more than 10 Gy) was an independent predictor of SARP. CONCLUSIONS: Our findings suggested that thoracic radiotherapy might be associated with clinical benefits to inoperable NSCLC in patients with severe pulmonary dysfunction and that ilV10 may be involved in the prediction of risk for SARP in these patients.

Impact of antibiotic use before definitive concurrent chemoradiation in patients with locally advanced non-small cell lung cancer.

PURPOSE: This study evaluated whether antibiotic treatment before chemoradiotherapy influenced outcomes in patients with locally advanced non-small cell lung cancer (LA-NSCLC). METHODS: The records of LA-NSCLC patients treated with chemoradiotherapy between 2010 and 2017 at West China Hospital of Sichuan University were retrospectively examined together with their antibiotic use (antibiotic type, duration of treatment, and time between discontinuation and chemoradiotherapy). The influence of antibiotics on progression-free survival (PFS) and overall survival (OS) was evaluated with Kaplan-Meier curves and univariate and multivariate Cox regression. RESULTS: Of 522 patients, 176 had received intravenous broad-spectrum antibiotics in the month before chemoradiotherapy. Antibiotic use was linked to both reduced PFS (7.9 vs. 13.4 months, p < 0.001) and OS (20.4 vs. 25.3 months, p = 0.049). Multivariate regression demonstrated that antibiotic treatment was an unfavorable independent prognostic factor for LA-NSCLC patients who received chemoradiotherapy (HR 1.234; 95% CI 1.019-1.494; p = 0.031). Prognosis was also influenced by antibiotic type, length of treatment, and interval between discontinuation and chemoradiotherapy initiation. ß­lactamase inhibitors were found to be the most harmful (median OS for ß­lactamase inhibitors/fluoroquinolones/cephalosporins: 16.5/19.9/25.9 months, p = 0.045). Cutoff values for interval and duration calculated by the X­tile procedure showed that intervals of 7-16 days or durations ≤ 6 days did not significantly affect OS relative to untreated patients (intervals: p = 0.9; duration: p = 0.93). CONCLUSION: Antibiotic treatment for longer than 6 days, especially with ß­lactamase inhibitors, was associated with poor prognosis. Furthermore, delaying chemoradiotherapy for 7-16 days after antibiotic discontinuation may reduce these negative effects.

Uncertain resection of highest mediastinal lymph node positive among pN2 non-small cell lung cancer patients: survival analysis of postoperative radiotherapy and driver gene mutations.

BACKGROUND AND PURPOSE: The role of postoperative radiotherapy (PORT) in uncertain resection of pN2 non-small cell lung cancer (NSCLC) with highest mediastinal lymph node positive has not been determined. We aim to evaluate the effect of PORT and driver gene mutation status (DGMS) on survival in such patients. METHODS: 140 selected patients were grouped according to whether they received PORT and their DGMS. Locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) of each group were evaluated by Kaplan-Meier analyses. COX regression was used to evaluate the effects of various factors on DFS and OS. RESULTS: Of 140 patients, thirty-four patients (24.3%) received PORT, and forty (28.6%) had positive driver gene mutation status (DGp). PORT significantly prolonged LRFS (p = 0.002), DFS (p = 0.019) and OS (p = 0.02), but not DMFS (p = 0.062). By subgroup analysis, in patients with negative driver gene mutation status (DGn), those receiving PORT had notably longer LRFS (p = 0.022) and DFS (p = 0.033), but not DMFS (p = 0.060) or OS (p = 0.215), compared to those not receiving PORT. Cox analysis showed that the number of positive lymph nodes (PLNs) and administration of PORT were independent prognostic factors of DFS, and pathology, PLNs, and DGMS may be prognostic factors of OS (all p < 0.05). CONCLUSION: Postoperative radiotherapy may improve locoregional recurrence-free and disease-free survival in patients with pN2 NSCLC with positive highest mediastinal lymph nodes, while driver gene mutation status impacted OS significantly. Only patients with positive driver gene mutations experienced significant overall survival benefits from postoperative radiotherapy.

Discovery of highly potent and selective 7-ethyl-10-hydroxycamptothecin-glucose conjugates as potential anti-colorectal cancer agents.

7-Ethyl-10-hydroxycamptothecin (SN38), a highly potent metabolite of irinotecan, has an anticancer efficacy 100-1000 folds more than irinotecan in vitro. However, the clinical application of SN38 has been limited due to the very narrow therapeutic window and poor water solubility. Herein, we report the SN38-glucose conjugates (Glu-SN38) that can target cancer cells due to their selective uptake via glucose transporters, which are overexpressed in most cancers. The in vitro antiproliferative activities against human cancer cell lines and normal cells of Glu-SN38 were investigated. One of the conjugates named 5b showed high potency and selectivity against human colorectal cancer cell line HCT116. Furthermore, 5b remarkably inhibited the growth of HCT116 in vivo. These results suggested that 5b could be a promising drug candidate for treating colorectal cancer.

An overview of PROTACs: a promising drug discovery paradigm.

Proteolysis targeting chimeras (PROTACs) technology has emerged as a novel therapeutic paradigm in recent years. PROTACs are heterobifunctional molecules that degrade target proteins by hijacking the ubiquitin-proteasome system. Currently, about 20-25% of all protein targets are being studied, and most works focus on their enzymatic functions. Unlike small molecules, PROTACs inhibit the whole biological function of the target protein by binding to the target protein and inducing subsequent proteasomal degradation. PROTACs compensate for limitations that transcription factors, nuclear proteins, and other scaffolding proteins are difficult to handle with traditional small-molecule inhibitors. Currently, PROTACs have successfully degraded diverse proteins, such as BTK, BRD4, AR, ER, STAT3, IRAK4, tau, etc. And ARV-110 and ARV-471 exhibited excellent efficacy in clinical II trials. However, what targets are appropriate for PROTAC technology to achieve better benefits than small-molecule inhibitors are not fully understood. And how to rationally design an efficient PROTACs and optimize it to be orally effective poses big challenges for researchers. In this review, we summarize the features of PROTAC technology, analyze the detail of general principles for designing efficient PROTACs, and discuss the typical application of PROTACs targeting different protein categories. In addition, we also introduce the progress of relevant clinical trial results of representative PROTACs and assess the challenges and limitations that PROTACs may face. Collectively, our studies provide references for further application of PROTACs.

Effect of cyasterone on intestinal flora in a BRAFV600E-mutant mouse model of colorectal cancer.

BRAF V600E-mutated colorectal cancer (CRC) is very aggressive and responds poorly to standard treatment. In this study, BRAFV600E-mutant mice with CRC were treated with intragastric cyasterone, a compound commonly used in traditional Chinese herbal medicine, for 21 days. Microbial DNA was extracted from mouse intestinal contents for 16S ribosomal RNA gene amplicon sequencing and analyzed. Our results indicated that cyasterone enhanced the diversity of the gut microbiota. The abundance of beneficial bacteria, such as Prevotellaceae, Muribaculaceae, and Ruminococcaceae was significantly higher in cyasterone-treated mice than controls. The abundance of Erysipelotrichaceae, a family of bacteria that promotes inflammation in the gut, was significantly positively correlated with tumor weight. Cyasterone is a potential inhibitor of BRAFV600E-mutant CRC via its effects on intestinal flora.

Discovery of potent and selective HER2 PROTAC degrader based Tucatinib with improved efficacy against HER2 positive cancers.

HER2 is a validated therapeutic target for HER2 positive breast cancer and gastric cancer. TKIs have significantly improved the prognosis of patients with HER2 positive cancer. However, the pan-HER TKIs always caused gastrointestinal and skin side effects, and acquired drug resistance inevitable compromised their therapeutic efficacy. Herein, we describe the discovery of the first potent and selective HER2 PROTAC degrader based Tucatinib with improved antitumor activity in vitro and in vivo. The preferred selective HER2 PROTAC, CH7C4, efficiently degraded HER2 with DC50 of 69 nM and Dmax of 96%, and inhibited the proliferation of BT-474 cells with IC50 of 0.047 ± 0.006 nM via long lasting HER2 degradation and strong repression of downstream pathway. Moreover, CH7C4 had acceptable pharmacokinetic profiles with a half-life of 5.31 h, and significantly inhibited the growth of BT-474 xenografts in vivo with TGI of 73%. As the first selective HER2 PROTAC degrader with better activity in vitro and in vivo than Tucatinib, CH7C4 provides new insights into the development of new therapeutic strategy for HER2 positive cancer.

Immune checkpoint inhibitor (ICI)-based treatment beyond progression with prior immunotherapy in patients with stage IV non-small cell lung cancer: a retrospective study.

Background: Although immune checkpoint inhibitors (ICIs) provide unprecedented survival improvement for patients with advanced non-small cell lung cancer (NSCLC), disease progression inevitably occurs. After ICIs failure, limited data exist on whether ICI-based treatment beyond progression (TBP) may be beneficial to advanced NSCLC. This retrospective study aimed to evaluate the efficacy of this treatment approach in advanced NSCLC and identify potential beneficial factors. Methods: Patients with stage IV NSCLC who received ICI-based treatment after the failure of prior PD-1/PD-L1 inhibitor treatments (monotherapy or combination therapy) between January 2016 and July 2020 were enrolled. Their clinical characteristics and treatment procedures were collected, and the follow-up would be performed. Results: A total of 204 patients were included. All patients had disease progression after prior immunotherapy, with 49.5% (101/204) of patients presenting with new metastasis lesions and the rest 50.5% (103/204) of patients' progression on originate lesions. Within the entire cohort, the median progression-free survival (PFS) and median overall survival (OS) of ICI-based TBP with prior immunotherapy were 5.0 months (95% CI: 4.5-5.5 months) and 15.7 months (95% CI: 14.7-16.8 months), respectively. The objective response rate (ORR) and disease control rate (DCR) were 9.3% and 74.0%, respectively. According to the multivariate analysis, ICI-based combination therapy [PFS: hazard ratio (HR), 0.48, 95% confidence interval (CI): 0.28-0.84, P=0.011] (OS: HR, 0.44, 95% CI: 0.23-0.85, P=0.014), not having targetable gene alterations (PFS: HR, 0.56, 95% CI: 0.40-0.79, P=0.001) (OS: HR, 0.57, 95% CI: 0.37-0.87, P=0.009), and good response to prior immunotherapy (PFS: HR, 0.36, 95% CI: 0.24-0.53, P<0.0001) (OS: HR, 0.31, 95% CI: 0.19-0.52, P<0.0001) were independently associated with improved PFS and OS. Moreover, disease progression due to appearances of new metastasis (OS: HR, 0.56, 95% CI: 0.37-0.84, P=0.005) was only associated with better OS. Conclusions: While the ORR in patients with advanced NSCLC receiving ICI-based TBP with prior immunotherapy was limited, the DCR was relatively high in our study which is encouraging. ICI-based treatment strategy may be a reasonable option for patients who progressed from prior immunotherapy. Further prospective studies on larger sample size are warranted.

Response to Pralsetinib Observed in Meningeal-Metastatic EGFR-Mutant NSCLC With Acquired RET Fusion: A Brief Report.

Introduction: RET is well known as an important driver gene in NSCLC. Moreover, RET is a rare acquired resistance mechanism to EGFR-mutant NSCLC. Only 36 NSCLC cases of coexistence of EGFR and RET were reported previously worldwide. So far, there have been no reports on the following: (1) whether combination of EGFR tyrosine kinase inhibitor (TKI) and RET TKI works for meningeal metastasis; (2) the concentrations of EGFR TKI and RET TKI in the cerebrospinal fluid (CSF) and plasma; and (3) whether RET fusions and EGFR mutation happened in the same clone or not. Methods: We reported a patient with an EGFR-mutant NSCLC with acquired RET fusions and meningeal metastasis treated with pralsetinib and osimertinib; the specimen was analyzed by next-generation sequencing (Illumina NovaSeq 6000 platform). Symptom improvement and magnetic resonance imaging scan were used for effect evaluation. Furthermore, we determined the concentrations of pralsetinib and osimertinib in CSF and plasma by means of liquid chromatography tandem mass spectrometry. We also detected RET fusion and EGFR L858R mutation by methods of fluorescence in situ hybridization and immunohistochemistry with continuous sections to analyze whether RET fusions coexist with EGFR mutation in the same clone or not. Results: The allele frequency of the RET fusion was detected to be 12.88%. This patient achieved a partial response, indicating pralsetinib combined with osimertinib may be clinically beneficial for meningeal metastasis in patients harboring acquired coexistent RET fusions. The concentrations of pralsetinib in the CSF and plasma were 704.76 nM and 91.31 µM, whereas those of osimertinib in the CSF and plasma were 23.70 nM and 2148.94 nM, respectively. RET fusion was found in the same clone of EGFR L858R mutation. Conclusions: Our finding of this case indicated that RET fusion and EGFR mutation occur in the same population of cell clones, rather than in different cell clones. Combined pralsetinib may be an effective way to overcome the resistance, even for meningeal metastasis, owing to high CSF distribution of pralsetinib.