Tumor response and progression-free survival as potential surrogate endpoints for overall survival in extensive stage small-cell lung cancer: findings on the basis of North Central Cancer Treatment Group trials

Development and validation of nomograms for predicting survival in small cell lung cancer patients with brain metastases: a SEER population-based analysis

OBJECTIVE

To develop prognostic nomograms for overall survival (OS) and cancer-specific survival (CSS) probabilities in small cell lung cancer (SCLC) patients with brain metastasis (BM).

METHODS

SCLC patients with BM from the Surveillance, Epidemiology, and End Results (SEER) database (2010-2015) were randomly allocated to training (n=1771) and validation (n=757) cohorts. Independent prognostic factors for OS and CSS were determined using univariate and multivariate Cox regression analyses in the training cohort, and prognostic nomograms for OS and CSS were constructed based on these factors. The efficacy of the nomograms was assessed using area under the receiver operating characteristic (ROC) curves (AUCs), calibration curves, decision curve analysis (DCA), net reclassification index (NRI), and integrated discrimination improvement (IDI), with the TNM staging model as a comparator.

RESULTS

Multivariate Cox analysis identified age, sex, race, tumor size, N staging, and presence of liver/bone/lung metastases, chemotherapy, and radiotherapy as independent prognostic factors for both OS and CSS. Prognostic nomograms were developed based on these factors. In both the training and validation cohorts, the AUC values of the nomograms for OS and CSS were significantly above 0.7, surpassing those for TNM staging. Calibration curves demonstrated a high degree of concordance between predicted and actual survival. The constructed nomograms showed superior clinical utility compared to the TNM staging system, as evidenced by NRI, IDI, and DCA.

CONCLUSIONS

This retrospective study successfully developed and validated prognostic nomograms for SCLC patients with BM, providing valuable tools for oncologists to enhance prognosis evaluation and guide clinical decision-making.

Evaluation of progression-free survival as a surrogate endpoint for overall survival in locally advanced or metastatic differentiated thyroid cancer: a systematic review

PURPOSE

Patients with locally advanced or metastatic differentiated thyroid cancer (DTC) have a variable prognosis, and the development of more effective treatment strategies is an important research topic. Overall survival (OS) is the gold standard for research endpoints in randomized controlled trials (RCTs), but observing an OS benefit requires the inclusion of a large number of patients and a long follow-up period. In this study, we aimed to investigate whether progression-free survival (PFS) could be used as a surrogate endpoint for OS in locally advanced or metastatic DTC clinical trials.

MATERIALS AND METHODS

We conducted a search in the PubMed and EMBASE databases to include all RCTs of locally advanced or metastatic DTC and extracted survival data. A weighted linear regression analysis was performed to explore the correlation between PFS benefit and OS benefit by taking the logarithm of the hazard ratios (HRs) of PFS and OS for each trial with a base of 10 and weighted by the number of patients in each RCT.

RESULTS

Seven RCTs, including 1410 patients, were included. At the trial level, PFS benefit was weakly correlated with OS benefit (R2 = 0.210, 95% CI: 0.000-0.811) and did not meet the statistical criteria for the surrogate endpoint.

CONCLUSION

This study does not support PFS as a surrogate endpoint for OS in locally advanced or metastatic DTC clinical trials.

TRIAL REGISTRATION

PROSPERO Identifier: CRD42022334898.

Comparative Effectiveness of Lurbinectedin for the Treatment of Relapsed Small Cell Lung Cancer in the Post-Platinum Setting: A Real-World Canadian Synthetic Control Arm Analysis

BACKGROUND

Based on findings from a single-arm, phase 2 basket trial (NCT02454972), lurbinectedin may be an effective treatment for individuals with small cell lung cancer (SCLC) who progressed on or after platinum-based chemotherapy.

OBJECTIVE

To estimate the comparative effectiveness of lurbinectedin versus the historical standard of care for relapsed SCLC in Canada.

METHODS

A synthetic control arm (SCA) analysis was conducted using real-world data. Population-level data were obtained from real-world databases in Alberta, Canada. Individuals diagnosed with SCLC who initiated post-platinum systemic therapy and met approximated eligibility criteria from the lurbinectedin trial were included in the SCA. Median overall survival (OS) in the SCA was estimated after adjusting for chemotherapy-free interval (CTFI; < 90 versus ≥ 90 days) and stage at initial diagnosis (extensive versus limited). The CTFI-adjusted hazard ratio was estimated using a Cox proportional hazards model.

RESULTS

One hundred seventy-four individuals were included in the SCA and 105 in the lurbinectedin trial. The adjusted median OS in the SCA was 6.1 months (95% CI 5.4-7.7 months; unadjusted: 6.7 months, 95% CI 6.0-7.7 months) versus 9.3 months (95% CI 6.3-11.8 months) in the lurbinectedin trial. The adjusted hazard ratio comparing lurbinectedin with the historical standard of care (referent group) was 0.61 (95% CI 0.45-0.82; unadjusted HR: 0.72; 95% CI 0.54-0.97). The hazard ratio was more pronounced among individuals with CTFI ≥ 90 days (HR: 0.49, 95% CI 0.33-0.73).

CONCLUSION

These findings suggest improved OS with lurbinectedin monotherapy versus the historical standard of care in Alberta, Canada.

Lung Large Cell Neuroendocrine Carcinoma: A Population-Based Retrospective Cohort Study

BACKGROUNDS

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rarely high-grade neuroendocrine carcinoma of the lung with features of both small cell and non-small cell lung cancer. In this study, we aim to construct a prognostic nomogram that integrates the clinical features and treatment options to predict disease-specific survival (DSS).

METHODS

A total of 713 patients diagnosed with LCNEC were from the US National Cancer Institute's Surveillance Epidemiology and End Results (SEER) registry between 2010-2016. Cox proportional hazards analysis was conducted to choose the significant predictors of DSS. External validation was performed using 77 patients with LCNEC in the West China Hospital Sichuan University between 2010-2018. The predictive accuracy and discriminative capability were estimated by the concordance index (C-index), calibration curve, and receiver operating characteristic (ROC) curve. The clinical applicability of the nomogram was verified through the decision curve analysis (DCA). Additionally, we conducted a subgroup analysis of data available in the external cohort that may impact prognosis but was not recorded in the SEER database.

RESULTS

Six independent risk factors for DSS were identified and integrated into the nomogram. The nomogram achieved good C- indexes of 0.803 and 0.767 in the training and validation group, respectively. Moreover, the calibration curves for the probability of survival showed good agreement between prediction by nomogram and actual observation in 1-, 3- and 5-year DSS. The ROC curves demonstrated the prediction accuracy of the established nomogram (all Area Under Curve (AUC) > 0.8). DCA exhibited the favorable clinical applicability of the nomogram in the prediction of LCNEC survival. A risk classification system was built which could perfectly classify LCNEC patients into high-, medium- and low-risk groups (p < 0.001). The survival analysis conducted on the West China Hospital cohort indicated that whole brain radiation therapy (WBRT), prophylactic cranial irradiation (PCI), surgical procedures, tumor grade, Ki-67, and PD-L1 expression were not significantly associated with DSS.

CONCLUSION

This study has effectively developed a prognostic nomogram and a corresponding risk stratification system, which demonstrate promising potential for predicting the DSS of patients with LCNEC.

MicroRNA signature of small-cell lung cancer after treatment failure: impact on oncogenic targets by miR-30a-3p control

Small-cell lung cancer (SCLC) is associated with a high mortality rate and limited treatment efficacy. We created a microRNA (miRNA) expression signature by RNA sequencing using specimens from patients with SCLC who had failed treatment. Forty-nine miRNAs were downregulated in SCLC tissues and were candidate tumor-suppressive miRNAs. In this signature, both guide and passenger strands were downregulated for five miRNAs (miR-30a, miR-34b, miR-34c, miR-223, and miR-4529). Recent studies have revealed that passenger strands of miRNAs are involved in the molecular pathogenesis of human cancer. Although miR-30a-5p (the guide strand) has been shown to be a tumor-suppressive miRNA in various types of cancers, miR-30a-3p (the passenger strand) function is not well characterized in SCLC cells. We investigated the functional significance of miR-30a-3p and oncogenic genes regulated by miR-30a-3p in SCLC cells. Ectopic expression assays showed that miR-30a-3p expression inhibited cell proliferation and induced cell cycle arrest and apoptosis in two SCLC cell lines. Furthermore, in silico database searches and gene expression assays identified 25 genes as putative targets of miR-30a-3p in SCLC cells. Luciferase reporter assays revealed that downstream neighbor of SON (DONSON) was directly regulated by miR-30a-3p in SCLC cells. Knockdown of DONSON induced cell cycle arrest in SCLC cells and DONSON overexpression were detected in SCLC clinical samples. Analyzing the regulatory networks of tumor-suppressive miRNAs may lead to the identification of therapeutic targets in SCLC.

The 6-min walk test as a primary end-point in interstitial lung disease

There is a need for clinical trial end-points to better assess how patients feel and function, so that interventions can be developed which alleviate symptoms and improve quality of life. Use of 6-min walk test (6MWT) outcomes as a primary end-point in interstitial lung disease (ILD) trials is growing, particularly for drugs targeting concurrent pulmonary hypertension. However, 6MWT outcomes may be influenced differentially by interstitial lung and pulmonary vascular components of ILD, making interpretation complicated. We propose that using 6MWT outcomes, including 6-min walk distance or oxygen desaturation, as primary end-points should depend upon the study population (how advanced the ILD is; whether vasculopathy is significant), the degree of disease progression, and, importantly, the effect of study treatment expected. We argue that the 6MWT as a single outcome measure is suitable as a primary end-point if the treatment goal is to improve functional performance or prevent disease progression within a study population of patients with advanced ILD or those with ILD and co-existent vasculopathy. In addition, we discuss the potential of composite primary end-points incorporating 6MWT outcomes, outlining important considerations to ensure that they are appropriate for the study population and treatment goals.

Post-progression survival after atezolizumab plus carboplatin and etoposide as first-line chemotherapy in small cell lung cancer has a significant impact on overall survival

BACKGROUND

The effect of first-line chemotherapy on overall survival (OS) may be significantly influenced by subsequent therapy for patients with extensive disease small cell lung cancer (ED-SCLC). Therefore, we evaluated the relationship between progression-free survival (PFS), post-progression survival (PPS), and OS of ED-SCLC patients treated with atezolizumab plus carboplatin and etoposide as first-line therapy.

METHODS

We analyzed the data of 57 patients with relapsed ED-SCLC treated with atezolizumab plus carboplatin and etoposide (AteCE) as first-line chemotherapy between August 2019 and September 2020. The respective correlations between PFS-OS and PPS-OS following first-line AteCE treatment were examined at the individual patient level.

RESULTS

Spearman's rank correlation analysis and linear regression analysis showed that PPS strongly correlated with OS (r = 0.93, p < 0.05, R²  = 0.85) and that PFS moderately correlated with OS (r = 0.55, p < 0.05, R²  = 0.28). Performance status at relapse (0-1/≥2), number of cycles of atezolizumab maintenance therapy (<3/≥3), and platinum rechallenge chemotherapy all significantly positively correlated with PPS (p < 0.05).

CONCLUSIONS

Upon comparing OS-PFS and OS-PPS in this patient population, OS and PPS were found to have a stronger correlation. These results suggest that performance status at relapse, atezolizumab maintenance, or chemotherapy rechallenge could affect PPS.

Analysis of a Real-World Progression Variable and Related Endpoints for Patients with Five Different Cancer Types

Introduction

We previously demonstrated that real-world progression (rwP) can be ascertained from unstructured electronic health record (EHR)-derived documents using a novel abstraction approach for patients with advanced non-small cell lung cancer (base case). The objective of this methodological study was to assess the reliability, clinical relevance, and the need for disease-specific adjustments of this abstraction approach in five additional solid tumor types.

Methods

Patients with metastatic breast cancer (mBC), advanced melanoma (aMel), small cell lung cancer (SCLC), metastatic renal cell carcinoma (mRCC), and advanced gastric/esophageal cancer (aGEC) were selected from a real-world database. Disease-specific additions to the base case were implemented as needed. The resulting abstraction approach was applied to each disease cohort to capture rwP events and dates. To provide comprehensive clinical context, real-world progression-free survival (rwPFS) and time to progression (rwTTP) were compared to real-world overall survival (rwOS), time to next treatment (rwTTNT), and time to treatment discontinuation (rwTTD). Endpoint estimates were assessed using the Kaplan–Meier method. Correlations between real-world endpoints and rwOS were calculated using Spearman’s ρ.

Results

Additions to the base-case rwP abstraction approach were required for mBC, aMel, and SCLC. Inter-abstractor agreement for rwP occurrence, irrespective of date, ranged from 88% to 97%. Occurrence of clinically relevant downstream events (new antineoplastic systemic therapy start, antineoplastic systemic therapy end, or death relative to the rwP event) ranged from 59% (aMel) to 72% (mBC). Median rwPFS ranged from 3.7 (aMel) to 7.7 (mBC) months, and median rwTTP ranged from 4.6 (aMel) to 8.3 (mRCC) months. Correlations between rwOS and rwPFS ranged from 0.52 (aMel) to 0.82 (SCLC). The correlation between rwOS and rwTTD was often lower relative to other comparisons (range 0.40–0.62).

Conclusion

Derivation of a rwP variable from EHR documentation is feasible and reliable across the five solid tumors. Endpoint analyses show that rwP produces clinically meaningful information.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02091-8.

ABBV-011, A Novel, Calicheamicin-Based Antibody-Drug Conjugate, Targets SEZ6 to Eradicate Small Cell Lung Cancer Tumors

In the past year, four antibody-drug conjugates (ADC) were approved, nearly doubling the marketed ADCs in oncology. Among other attributes, successful ADCs optimize targeting antibody, conjugation chemistry, and payload mechanism of action. Here, we describe the development of ABBV-011, a novel SEZ6-targeted, calicheamicin-based ADC for the treatment of small cell lung cancer (SCLC). We engineered a calicheamicin conjugate that lacks the acid-labile hydrazine linker that leads to systemic release of a toxic catabolite. We then screened a patient-derived xenograft library to identify SCLC as a tumor type with enhanced sensitivity to calicheamicin ADCs. Using RNA sequencing (RNA-seq) data from primary and xenograft SCLC samples, we identified seizure-related homolog 6 (SEZ6) as a surface-expressed SCLC target with broad expression in SCLC and minimal normal tissue expression by both RNA-seq and IHC. We developed an antibody targeting SEZ6 that is rapidly internalized upon receptor binding and, when conjugated to the calicheamicin linker drug, drives potent tumor regression in vitro and in vivo. These preclinical data suggest that ABBV-011 may provide a novel treatment for patients with SCLC and a rationale for ongoing phase I studies (NCT03639194).

Clinical impact of post-progression survival in patients with locally advanced non-small cell lung cancer after chemoradiotherapy

BACKGROUND

The efficacy of first-line chemoradiotherapy for overall survival (OS) might be confounded by the subsequent treatments in patients with locally advanced non-small cell lung cancer (NSCLC). In this study, we assessed the associations of progression-free survival (PFS) and post-progression survival (PPS) with OS after chemoradiotherapy for locally advanced NSCLC using patient-level data.

PATIENTS AND METHODS

Between January 2011 and December 2018, 45 patients with locally advanced NSCLC who had received first-line chemoradiotherapy and in whom recurrence occurred were analysed. The associations of PFS and PPS with OS were analysed at the individual level.

RESULTS

Linear regression and Spearman rank correlation analyses revealed that PPS was strongly correlated with OS (r = 0.72, p < 0.05, R2 = 0.54), whereas PFS was moderately correlated with OS (r = 0.58, p < 0.05, R² = 0.34). The Glasgow prognostic score and liver metastases at recurrence were significantly associated with PPS (p < 0.001).

CONCLUSIONS

The current analysis of individual-level data of patients treated with first-line chemoradiotherapy implied that PPS had a higher impact on OS than PFS in patients with locally advanced NSCLC. Additionally, current perceptions indicate that treatment beyond progression after first-line chemoradiotherapy might strongly affect OS.

Progression-Free Survival and Time to Progression as Potential Surrogate Endpoints for Overall Survival in Chemoradiotherapy Trials in Limited-Stage Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Purpose

To investigate whether progression-free survival (PFS) or time to progression (TTP) could be a valid surrogate endpoint for overall survival (OS) in patients with limited-stage small-cell lung cancer (LS-SCLC) receiving combined chemoradiotherapy.

Methods

Literature searching was performed in PubMed, Embase, and The Cochrane Library up to 2021. Prediction models were firstly established using data from phase III randomized controlled trials (RCTs) and then externally validated in phase II and retrospective studies. Correlation analysis was evaluated by a weighted linear regression model at both trial and arm levels. Cross-validation was performed to assess the consistency and robustness of the established models.

Results

37 studies, including 15 phase III RCTs, 12 phase II studies, and 10 retrospective studies, were selected in the final analysis. In trial-level surrogacy, a very good correlation was observed between hazard ratios (HRs) of PFS/TTP and OS (R2 = 0.783, 95% CI 0.771–0.794). In arm-level surrogacy, very good correlations were also observed between 2-year (R2 = 0.823, 95% CI 0.814–0.832), 3-year (R2 = 0.843, 95% CI 0.833–0.850), 5-year (R2 = 0.852, 95% CI 0.843–0.859) PFS/TTP, and 5-year OS. An excellent correlation was observed between 4-year PFS/TTP and 5-year OS (R2 = 0.906, 95% CI 0.901–0.910). Cross-validation demonstrated reasonable overall consistency. External validation in phase II and retrospective studies showed good agreement (R2, 0.728–0.824).

Conclusions

PFS/TTP was a valid surrogate endpoint for OS in patients with LS-SCLC receiving combined chemoradiotherapy. The finding provides high-level evidence to support PFS/TTP as the primary endpoint in clinical trials so as to speed up introducing novel agents to the treatment of LS-SCLC.

Modelling approaches for histology-independent cancer drugs to inform NICE appraisals: a systematic review and decision-framework

BACKGROUND

The first histology-independent marketing authorisation in Europe was granted in 2019. This was the first time that a cancer treatment was approved based on a common biomarker rather than the location in the body at which the tumour originated. This research aims to explore the implications for National Institute for Health and Care Excellence appraisals.

METHODS

Targeted reviews were undertaken to determine the type of evidence that is likely to be available at the point of marketing authorisation and the analyses required to support National Institute for Health and Care Excellence appraisals. Several challenges were identified concerning the design and conduct of trials for histology-independent products, the greater levels of heterogeneity within the licensed population and the use of surrogate end points. We identified approaches to address these challenges by reviewing key statistical literature that focuses on the design and analysis of histology-independent trials and by undertaking a systematic review to evaluate the use of response end points as surrogate outcomes for survival end points. We developed a decision framework to help to inform approval and research policies for histology-independent products. The framework explored the uncertainties and risks associated with different approval policies, including the role of further data collection, pricing schemes and stratified decision-making.

RESULTS

We found that the potential for heterogeneity in treatment effects, across tumour types or other characteristics, is likely to be a central issue for National Institute for Health and Care Excellence appraisals. Bayesian hierarchical methods may serve as a useful vehicle to assess the level of heterogeneity across tumours and to estimate the pooled treatment effects for each tumour, which can inform whether or not the assumption of homogeneity is reasonable. Our review suggests that response end points may not be reliable surrogates for survival end points. However, a surrogate-based modelling approach, which captures all relevant uncertainty, may be preferable to the use of immature survival data. Several additional sources of heterogeneity were identified as presenting potential challenges to National Institute for Health and Care Excellence appraisal, including the cost of testing, baseline risk, quality of life and routine management costs. We concluded that a range of alternative approaches will be required to address different sources of heterogeneity to support National Institute for Health and Care Excellence appraisals. An exemplar case study was developed to illustrate the nature of the assessments that may be required.

CONCLUSIONS

Adequately designed and analysed basket studies that assess the homogeneity of outcomes and allow borrowing of information across baskets, where appropriate, are recommended. Where there is evidence of heterogeneity in treatment effects and estimates of cost-effectiveness, consideration should be given to optimised recommendations. Routine presentation of the scale of the consequences of heterogeneity and decision uncertainty may provide an important additional approach to the assessments specified in the current National Institute for Health and Care Excellence methods guide.

FURTHER RESEARCH

Further exploration of Bayesian hierarchical methods could help to inform decision-makers on whether or not there is sufficient evidence of homogeneity to support pooled analyses. Further research is also required to determine the appropriate basis for apportioning genomic testing costs where there are multiple targets and to address the challenges of uncontrolled Phase II studies, including the role and use of surrogate end points.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Evidence Synthesis programme and will be published in full in Health Technology Assessment; Vol. 25, No. 76. See the NIHR Journals Library website for further project information.

Progression-free survival assessed per immune-related or conventional response criteria, which is the better surrogate endpoint for overall survival in trials of immune-checkpoint inhibitors in lung cancer: A systematic review and meta-analysis

Progression-free survival (PFS) has been used as a surrogate endpoint for overall survival (OS) in lung cancer trials. The pattern of response to immune-checkpoint inhibitors (ICIs) differs from that to conventional chemotherapy, so immune-related response evaluation criteria were proposed. This study aims at determining which PFS measure, PFS assessed per immune-related response evaluation criteria (iPFS), or conventional criteria (cPFS), is the better surrogate endpoint for OS in trials of ICIs in lung cancer. We selected clinical trials in lung cancer that administered ICIs to at least one arm and reported both median OS and median PFS from PubMed, Embase, and The Cochrane Library. We compared the correlation between treatment effect (hazard ratio) on OS and cPFS or iPFS and the correlation between median OS and median cPFS or iPFS using weighted linear regression at trial level. We analyzed 78 ICI arms (13,438 patients) from 54 studies, including 66 arms with cPFS, seven arms with iPFS, and five arms with both kinds of PFS. We demonstrated an excellent correlation between treatment effect (hazard ratio) on OS and iPFS (RWLS2  = 0.91), while the correlation was moderate for cPFS (RWLS2  = 0.38). Similarly, the correlation between median OS and median iPFS was also strong (RWLS2 ranging from 0.86 to 0.96) across different phases of trials and different types of lung cancer, ICI, and treatment modalities, while it was much weaker for median cPFS (RWLS2 ranging from 0.28 to 0.88). In conclusion, iPFS provides better trial-level surrogacy for OS than cPFS in trials of ICIs in lung cancer.

Consideration of Surrogate Endpoints for Overall Survival Associated With First-Line Immunotherapy in Extensive-Stage Small Cell Lung Cancer

Background

The combination of immune checkpoint inhibitors (ICIs) and chemotherapy is known to improve overall survival (OS) in patients with extensive-stage small cell lung cancer (ES-SCLC). ICIs have different response patterns and survival kinetics characteristics from those of the traditional chemotherapy. In first-line treatment for ES-SCLC, there is an urgent need for surrogate endpoints for the early and accurate prediction of OS. This study aimed to assess progression-free survival (PFS), milestone OS rate, milestone restricted mean survival time (RMST), overall response rate (ORR), and disease control rate (DCR) as proposed surrogate endpoints for OS in ES-SCLC for first-line immunotherapy trials.

Methods

Between January 1, 2013, and December 2020, published articles on randomized clinical trials of ICIs plus chemotherapy in patients with ES-SCLC as first-line therapy were searched in PubMed. Abstracts from the ESMO, ASCO, and WCLC, reported from 2018 onwards, were also searched. A weighted regression analysis based on the weighted least squares method was performed on log-transformed estimates of treatment effect, and the determination coefficient (R²) was calculated to evaluate the association between treatment effect on the surrogate endpoint and OS.

Results

Seven trials, representing 3,009 patients, were included to make up a total of 16 analyzed arms. The ratio of the 12-month OS milestone rate (r = −0.790, P = 0.011, R² = 0.717) and 12-month OS milestone RMST (r = 0.798, P = 0.010, R² = 0.702) was strongly correlated with the hazard ratio (HR) for OS. The strongest association was observed between the ratio of the 24-month OS milestone RMST and the HR for OS (r = 0.922, P = 0.001, R² = 0.825). No associations were observed between the HR for OS and PFS and the RR for ORR and DCR.

Conclusions

The results suggested a strong correlation among the ratio of OS milestone rates at 12 months, ratios of OS milestone RMSTs at 12 and 24 months, and HR for OS. The results indicate that OS milestone rates and OS milestone RMSTs could be considered surrogate endpoints of OS in future first-line immunotherapy trials for ES-SCLC.

Real-world treatment patterns and outcomes in small-cell lung cancer: a systematic literature review

Background

Small-cell lung cancer (SCLC) accounts for 12-15% of lung cancers and is associated with poor survival outcomes and high symptom burden. This study employed a broad, systematic search strategy and timeframe to identify evidence on real-world treatment patterns and outcomes for SCLC outside the USA, including understanding sub-populations such as extensive-stage (ES) or limited-stage (LS) disease.

Methods

Databases (MEDLINE, Embase, and EBM reviews) were searched for journal articles published in the English language between 1 January 2000-1 March 2020 and supplemented by hand searching of conference abstracts and posters presented at conferences between 1 January 2016-1 March 2020 reporting real-world treatment outcomes in patients with SCLC. A targeted clinical guideline review was also completed.

Results

One-hundred studies provided quantitative data; 57 were available as full-text articles, whilst the remaining 43 were presented as abstracts or posters. The majority (80 studies, 80%) of included studies reported treatment in the first-line setting, where platinum-based chemotherapy and chemoradiotherapy was the most commonly used treatment strategy, in line with current treatment guidelines in SCLC. First-line treatments were found to have a high response rate; however, most patients relapsed early. No studies reported treatment or outcomes with immune-oncology therapies. Second-line treatment options were very limited, and primarily consisted of either re-treatment with first-line regimen or topotecan, but the prognosis for these patients remained poor. Outcomes were particularly poor amongst those with ES or relapsed disease vs. LS disease.

Conclusions

SCLC treatment patterns and short survival outcomes have remained constant over the previous 20 years. Due to the search timeframe, none of the studies identified reported on the impact of recently approved immune-oncology therapies in SCLC. Further data is needed on the impact of immunotherapies on treatment patterns and real-world outcomes in SCLC.

A new nomogram and risk classification system for predicting survival in small cell lung cancer patients diagnosed with brain metastasis: a large population-based study

BACKGROUND

The prognosis of patients with small cell lung cancer (SCLC) is poor, most of them are in the extensive stage at the time of diagnosis, and are prone to brain metastasis. In this study, we established a nomogram combined with some clinical parameters to predict the survival of SCLC patients with brain metastasis.

METHODS

The 3522 eligible patients selected from the SEER database between 2010 and 2015 were randomly divided into training cohort and validation cohort. Univariate and multivariate Cox regression analysis were used to evaluate the ability of each parameter to predict OS. The regression coefficients obtained in multivariate analysis were visualized in the form of nomogram, thus a new nomogram and risk classification system were established. The calibration curves were used to verify the model. And ROC curves were used to evaluate the discrimination ability of the newly constructed nomogram. Survival curves were made by Kaplan-Meier method and compared by Log rank test.

RESULTS

Univariate and multivariate analysis showed that age, race, sex, T stage, N stage and marital status were independent prognostic factors and were included in the predictive model. The calibration curves showed that the predicted value of the 1- and 3-year survival rate by the nomogram was in good agreement with the actual observed value of the 1- and 3-year survival rate. And, the ROC curves implied the good discrimination ability of the predictive model. In addition, the results showed that in the total cohort, training cohort, and validation cohort, the prognosis of the low-risk group was better than that of the high-risk group.

CONCLUSIONS

We established a nomogram and a corresponding risk classification system to predict OS in SCLC patients with brain metastasis. This model could help clinicians make clinical decisions and stratify treatment for patients.

Surrogate endpoint evaluation using data from one large global randomized controlled trial

BACKGROUND

Robust identification of surrogate endpoints can help accelerate the development of pharmacotherapies for diseases traditionally evaluated using true endpoints associated with prolonged follow-up. The meta-analysis-based surrogate endpoint evaluation (SEE) integrates data from multiple, usually smaller, trials to statistically confirm a surrogate endpoint as a robust proxy for the true endpoint. To test the applicability of SEE when only a single, larger trial is available, we analysed the cardiovascular (CV) survival endpoint from the large multinational trial LEADER (9340 subjects) that confirmed the CV safety of a diabetes drug (liraglutide). We evaluated if using country as a trial unit adequately facilitated the meta-analysis and calculation of R² by country group.

METHODS

Data were grouped by country, ensuring at least 30 CV deaths (497 in total) in each of the nine resulting by-country groups. In a two-step SEE on the grouped dataset, we first fitted the group-specific Cox proportional hazard models; next, on the trial-level, we regressed the estimated hazard ratio (HR; liraglutide vs placebo) of the true endpoints (CV death: 497 events, or all-cause death: 828 events) on the HR of the surrogate endpoint (major CV adverse event [MACE]: 1302 events) and derived the group-specific R² and its 95% confidence interval (CI).

RESULTS

Group-level surrogacy of MACE was supported for CV death but not for all-cause death, with [Formula: see text] values of 0.85 [0.63;1.00]_{95% CI} and 0.23 [0.00;0.67]_{95% CI}, respectively. Sensitivity analyses using different grouping approaches (e.g. grouping by region) corroborated the robustness of the conclusions as well as the appropriateness of the data-grouping approaches.

CONCLUSIONS

We derived a specific grouping approach to successfully apply SEE on data from a single trial. This may allow for the statistically robust identification and validation of surrogate endpoints based on the abundance of large monolithic outcome trials conducted as part of drug development programmes in, for example, diabetes.

FDA Approval Summary: Atezolizumab and Durvalumab in Combination with Platinum-Based Chemotherapy in Extensive Stage Small Cell Lung Cancer

The U.S. Food and Drug Administration (FDA) granted approval to atezolizumab and durvalumab in March of 2019 and 2020, respectively, for use in combination with chemotherapy for first-line treatment of patients with extensive stage small cell lung cancer. These approvals were based on data from two randomized controlled trials, IMpower133 (atezolizumab) and CASPIAN (durvalumab). Both trials demonstrated an improvement in overall survival (OS) with anti-programmed death ligand 1 antibodies when added to platinum-based chemotherapy as compared with chemotherapy alone. In IMpower133, patients receiving atezolizumab with etoposide and carboplatin demonstrated improved OS (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.54-0.91; p = .0069), with median OS of 12.3 months compared with 10.3 months in patients receiving etoposide and carboplatin. In CASPIAN, patients receiving durvalumab with etoposide and either cisplatin or carboplatin also demonstrated improved OS (HR, 0.73; 95% CI, 0.59-0.91; p = .0047) with median OS of 13.0 months compared with 10.3 months in patients receiving etoposide and either cisplatin or carboplatin. The safety profiles of both drugs were generally consistent with known toxicities of immune-checkpoint inhibitor therapies. This review summarizes the FDA perspective and data supporting the approval of these two agents. IMPLICATIONS FOR PRACTICE: Effective therapeutic options for small cell lung cancer (SCLC) are limited, and there has been modest improvement in the overall survival (OS) of patients with SCLC over the past 3 decades. The approvals of atezolizumab and of durvalumab in combination with chemotherapy for first-line treatment of patients with extensive stage SCLC represent the first approved therapies with OS benefit for this patient population since the approval of etoposide in combination with other approved chemotherapeutic agents. Additionally, the efficacy results from IMpower133 and CASPIAN lay the groundwork for possible further evaluation in other treatment settings in this disease.

Concordance index: Surrogacy of progression-free survival for overall survival

In oncology clinical trials, the primary endpoint is often time to an event of clinical interest, e.g., time to disease progression or time to death. As a result, progression-free survival (PFS: the time from initiation of treatment till disease progression or death whichever occurs first) and overall survival (OS: the time from initiation of treatment till death) are the focus of statistical analysis in comparison of two treatment arms. It is often argued that PFS may serve as a surrogate endpoint for OS, while the validity of such surrogacy is still under debates in different types of cancer. In practice, one may observe a significant difference in PFS but no significant difference in OS; or vice versa. We provide a concordance index (C-index) to measure the degree of concordance between PFS and OS, and elaborate on the PFS vs OS discrepancies using the C-index using simulation studies and real trial analysis.

Real World Analysis of Small Cell Lung Cancer Patients: Prognostic Factors and Treatment Outcomes

In this observational study, we assessed treatment patterns and prognostic factors in patients with small cell lung cancer (SCLC) in a large state-mandated healthcare organization in Israel. Methods: All incident cases with histologically confirmed SCLC who initiated systemic anti-cancer treatment between 2011 and 2017 were identified. Treatment patterns and overall survival (OS) were evaluated for each line of therapy. Results: A total of 235 patients were identified (61% male, median age 64 years, 95% ever smokers, 64% had extensive stage). The first-line treatment was platinum-etoposide regimen for 98.7% of the cohort. The second and third-line regimen were given to 43% and 12% of patients, respectively. Mean OS for extensive and limited stage patients was 9.1 and 23.5 months respectively. In a multivariable model, increased risk for mortality was observed among patients with an ECOG performance status (PS) of 2 compared to a PS of 0-1 for the extensive stage patients (Hazard ratio (HR) = 1.63, 95% confidence ratios (CI): 1.00-2.65); and for males compared to females for the limited stage patients (HR = 2.17; 95% CI: 1.12-4.20). Regarding all 2nd line patients in a multivariable model incorporating relevant confounding factors, demonstrated a significantly better outcome with platinum-based regimens compared to topotecan. Median survival after initiation of 2nd line in platinum-sensitive patients was longer (p = 0.056) for those re-challenged with platinum-based regimen (n = 7): 6.8mo (6.1-not reported (NR)), compared with those switched to a different treatment (n = 27): 4.5 mo (2.6-6.6) for extensive stage patients, and a non-significant difference was also observed for limited stage patients. Conclusion: To our knowledge, this is one of the largest real-world studies of SCLC patients. OS for SCLC patients was similar to that reported in clinical trials. PS for extensive stage patients and sex for limited stage patients were significant correlates of prognosis. Re-challenge of the platinum-based doublet was associated with longer OS compared to switching treatment in extensive stage patients.

Paraneoplastic Focal Outer Retinitis and Optic Neuropathy in a Patient with Small Cell Lung Carcinoma and Anti-CRMP5, Anti-HU and Anti-Amphiphysin Antibodies

Our aim is to describe clinical and optical coherence tomographic features of acute paraneoplastic focal outer retinitis associated with optic neuropathy in a patient diagnosed with small cell lung carcinoma. Bilateral focal outer retinitis, bilateral optic disc oedema and vitritis were identified in a patient with progressive bilateral visual loss and ataxia. Spectral domain optical coherence tomography (SD-OCT) revealed various extents of granular hyperreflectivity and atrophy of the macular outer retinal layers. Serum and cerebrospinal fluid positivity for anti-CRMP5, anti-HU and anti-amphiphysin antibodies intensified the search for an underlying malignancy, and a small cell lung carcinoma (SCLC) was finally diagnosed. Local and oral steroids along with systemic chemotherapy and radiotherapy achieved cancer remission and partial recovery from the ophthalmic manifestations. Focal outer retinitis associated with optic disc oedema and antibody positivity facilitated the diagnosis of SCLC in a localized stage. SD-OCT allowed the characterization of this entity, expanding the spectrum of paraneoplastic ophthalmological syndromes.

The combination of pretreatment prognostic nutritional index and neuron-specific enolase enhances prognosis predicting value of small cell lung cancer

INTRODUCTION

Tumor and immune-inflammatory biomarkers have been demonstrated to be closely associated with cancer prognosis.

OBJECTIVE

The present study aims to assess the prognostic value of pretreatment prognostic nutritional index (PNI), carcinoembryonic antigen (CEA), and neuron-specific enolase (NSE) in small cell lung cancer (SCLC).

METHODS

A retrospective analysis of 301 SCLC patients treated with platinum-based chemotherapy was performed. Overall survival (OS) was assessed by Kaplan-Meier and multivariate Cox hazard analyses.

RESULTS

The median OS for total cases was 15.0 months. On univariate analysis, tumor stage (P < 0.001), pretreatment PNI (P < 0.001), CEA (P = 0.039), NSE (P = 0.010), distant metastasis numbers (P < 0.001), and thoracic radiotherapy (P < 0.001) were found to be the predictors of OS. Multivariate analysis showed limited stage, high PNI, NSE < 15 μg/L, and chemoradiotherapy were positive independent prognostic factors (P < 0.05). Low PNI and NSE ≥ 15 μg/L were closely correlated with a high tumor burden status. Three cohorts of SCLC with significant different survival outcomes were divided based on variable PNI and NSE levels. Patients with high PNI and NSE < 15 μg/L showed the best OS of 24.5 months, while patients with low PNI and NSE ≥ 15 μg/L had the worst survival outcome of 10.0 months. Patients with low PNI and NSE < 15 μg/L or high PNI and NSE ≥ 15 μg/L had the similar outcome of 16.5 and 17.0 months, respectively.

CONCLUSIONS

Pretreatment PNI and NSE were independent prognostic factors of SCLC. The combination of PNI and NSE enhanced the OS predicting ability, and patients with high PNI and NSE < 15 μg/L had the best survival outcome.

A systematic review of meta-analyses assessing the validity of tumour response endpoints as surrogates for progression-free or overall survival in cancer

BACKGROUND

Tumour response endpoints, such as overall response rate (ORR) and complete response (CR), are increasingly used in cancer trials. However, the validity of response-based surrogates is unclear. This systematic review summarises meta-analyses assessing the association between response-based outcomes and overall survival (OS), progression-free survival (PFS) or time-to-progression (TTP).

METHODS

Five databases were searched to March 2019. Meta-analyses reporting correlation or regression between response-based outcomes and OS, PFS or TTP were summarised.

RESULTS

The systematic review included 63 studies across 20 cancer types, most commonly non-small cell lung cancer (NSCLC), colorectal cancer (CRC) and breast cancer. The strength of association between ORR or CR and either PFS or OS varied widely between and within studies, with no clear pattern by cancer type. The association between ORR and OS appeared weaker and more variable than that between ORR and PFS, both for associations between absolute endpoints and associations between treatment effects.

CONCLUSIONS

This systematic review suggests that response-based endpoints, such as ORR and CR, may not be reliable surrogates for PFS or OS. Where it is necessary to use tumour response to predict treatment effects on survival outcomes, it is important to fully reflect all statistical uncertainty in the surrogate relationship.

Hazard ratio of progression-free survival is an excellent predictor of overall survival in phase III randomized controlled trials evaluating the first-line chemotherapy for extensive-disease small-cell lung cancer

Background

Whether hazard ratio (HR) of progression-free survival (HRpfs), odds ratio (OR) of response rate (ORrr), OR of disease control rate (ORdcr), and OR of 1-year overall survival (ORos1y) used for extensive-disease small-cell lung cancer (ED-SCLC) correlate with HR of overall survival (HRos) at a randomized-trial level, especially for a trial that evaluates molecular-targeted therapy (MTT) or immune-checkpoint inhibitor (ICI), is unclear.

Methods

We included an individually randomized controlled trial (RCT) comparing two regimens as the first-line treatment for chemo-naive ED-SCLC, which have been reported in English-language since 2000. A weighted Spearman’s rank correlation coefficient (r) was evaluated.

Results

We finally found 42 eligible articles consisted of 11,478 cases. Estimated r with HRos were as followings: HRpfs (29 trial, 8,573 cases, r=0.87), ORrr (39 trials, 11,030 cases, r=0.47), ORdcr (29 trials, 7,799 cases, r=0.48), and ORos1y (40 trials, 11,250 cases, r=0.69). Phase III subgroup (16 trials, 7,079 cases) yielded an excellent r between HRpfs and HRos of 0.96. ORdcr presented the best correlation with HRos for phase II trial subgroup (r=−0.64); however, this result was mainly calculated from MTT trials. HRpfs may overestimate the efficacy of MMT in a phase II trial. ORrr and ORdcr might undervalue the efficacy of ICI even in a phase III trial.

Conclusions

HRpfs can be a good surrogate of HRos, especially in a phase III trial. Depending on a single outcome in a randomized phase II trial may result in unneeded phase III trial or inappropriate abandonment of the regimen.

Cancer therapy: Attempt cure or manage drug resistance?

Cancer treatment is often aimed at achieving rapid, large, and sustained reductions in tumor burden. Even when these strong responses are achieved, treatment frequently fails due to the emergence of drug-resistant cell lineages. Over the last decade, a variety of authors have suggested that treatment should instead be aimed at containing resistance rather than curing the patient. That new philosophy poses a dilemma: how to choose between treatment regimens that can sometimes cure the patient and regimens that can delay progression but not cure the patient? Here, we investigate that choice. We define aspects of the evolution and ecology of tumor dynamics that determine whether it is better to attempt cure or to manage resistance. Even when it is possible to manage resistance and delay progression, this may not be the best treatment option. We show that the best option depends on how "cure" and "delaying progression" are prioritized, and how those priorities will vary among patients. We also discuss the difficulties of comparing in clinical trials traditional strategies that can sometimes successfully cure to alternative approaches where cure is not possible. More generally, where resistance management is possible, there are new challenges in communicating options to patients, setting treatment guidelines, and evaluating data from clinical trials.

Phase II Study of Arginine Deprivation Therapy With Pegargiminase in Patients With Relapsed Sensitive or Refractory Small-cell Lung Cancer

BACKGROUND

Pre-clinical studies indicated that arginine-deprivation therapy using pegylated arginine deiminase (pegargiminase, ADI-PEG 20) may be effective in patients with argininosuccinate synthetase 1 (ASS1)-deficient small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients were enrolled into either a 'sensitive' disease cohort (≥ 90 days response to first-line chemotherapy) or a 'refractory' disease cohort (progression while on chemotherapy or < 90 days afterwards or ≥ third-line treatment). Patients received weekly intramuscular pegargiminase, 320 IU/m² (36.8 mg/m²), until unacceptable toxicity or disease progression. The primary endpoint was tumor response assessed by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 with secondary endpoints including tolerability, pharmacodynamics, and immunogenicity.

RESULTS

Between January 2011 and January 2014, 22 patients were enrolled: 9 in the sensitive disease cohort and 13 in the refractory disease cohort. At a pre-planned interim analysis, the best overall response observed was stable disease in 2 patients in each cohort (18.2%). Owing to the lack of response and slow accrual in the sensitive disease cohort, the study was terminated early. Pegargiminase treatment was well-tolerated with no unexpected adverse events or discontinuations.

CONCLUSION

Although pegargiminase monotherapy in SCLC failed to meet its primary endpoint of RECIST-confirmed responses, more recent molecular stratification, including MYC status, may provide new opportunities moving forward.

Outcomes with immune checkpoint inhibitors for relapsed small-cell lung cancer in a Swiss cohort

OBJECTIVES

Early clinical trials showed promising outcomes with immune-checkpoint inhibitors (ICI) in a subset of patients with relapsed small-cell lung carcinoma (SCLC). The aim of this retrospective analysis was to assess the efficacy and safety of ICI for relapsed SCLC in a real-world patient population.

METHODS

Nine cancer centres in Switzerland contributed data to this cohort. Responses were assessed by the local investigators using standard RECIST v1.1 criteria. Progression-free survival (PFS) and overall survival (OS) were analysed by the Kaplan-Meier method. Associations between potential predictive markers and survival endpoints were probed by Cox proportional hazards.

RESULTS

Forty-five patients were included in the analysis. Median age was 63 years, 73% were males and 18% had an ECOG performance status (PS) ≥ 2. ICIs were given as second-line treatment in 60%. Twenty-four patients (53%) received ipilimumab with nivolumab. Twenty-eight patients (62%) had undergone irradiation (RT) prior to or during ICI. Overall response rate (ORR) was 29% and median PFS and OS were 2.3 and 6.5 months, respectively. Median duration of response was 9 months (95% CI 2.8-NA). Five patients maintained their response for > 6 months, all of them receiving combination treatment. There were no new safety signals.

CONCLUSION

This is the first report of "real-world" data on ICI in relapsed SCLC also including patients with poor PS. Promising durable responses were observed. No biological prognostic marker could be identified.

Lineage plasticity in cancer: a shared pathway of therapeutic resistance

Lineage plasticity, the ability of cells to transition from one committed developmental pathway to another, has been proposed as a source of intratumoural heterogeneity and of tumour adaptation to an adverse tumour microenvironment including exposure to targeted anticancer treatments. Tumour cell conversion into a different histological subtype has been associated with a loss of dependency on the original oncogenic driver, leading to therapeutic resistance. A well-known pathway of lineage plasticity in cancer - the histological transformation of adenocarcinomas to aggressive neuroendocrine derivatives - was initially described in lung cancers harbouring an EGFR mutation, and was subsequently reported in multiple other adenocarcinomas, including prostate cancer in the presence of antiandrogens. Squamous transformation is a subsequently identified and less well-characterized pathway of adenocarcinoma escape from suppressive anticancer therapy. The increased practice of tumour re-biopsy upon disease progression has increased the recognition of these mechanisms of resistance and has improved our understanding of the underlying biology. In this Review, we provide an overview of the impact of lineage plasticity on cancer progression and therapy resistance, with a focus on neuroendocrine transformation in lung and prostate tumours. We discuss the current understanding of the molecular drivers of this phenomenon, emerging management strategies and open questions in the field.

Treatment beyond four cycles of first line Platinum and Etoposide chemotherapy in real-life patients with stage IV Small Cell Lung Cancer: a retrospective study of the Merseyside and Cheshire Cancer network

Background

Dose intensity and dose density of first line Platinum and Etoposide (PE) do not influence Overall Survival (OS) of Small Cell Lung Cancer (SCLC) patients. The effect of treatment length, however, remains unclear. Current guidelines recommend treating beyond 4 cycles -up to 6-, in patients that respond to and tolerate systemic treatment. This has led to variable practice both in clinical practice and clinical research. Here we aimed at quantifying the possible clinical benefit of the extended regimen in our real-life patients treated with PE doublet.

Methods

Of all patients with SCLC treated in our network with non-concurrent first line PE chemotherapy between 2008 and 2015, we identified and described patients that received 4 cycles (4c) or more (> 4c), and analysed patients with stage IV disease.

Results

Two hundred forty-one patients with stage IV had 4c and 69 had > 4c. The latter were more likely to have sequential thoracic radiotherapy, which suggested a lower metastatic burden. Nevertheless, there were no statistically significant differences when comparing clinical outcomes. The median Duration of Response (DoR; time from last chemotherapy cycle to progression) was 5 months in both groups (HR 1.22; 95% CI 0.93–1.61). Median Progression Free Survival (PFS; time from diagnosis to radiological progression) was 8 months (4c) versus 9 months (> 4c) (HR 0.86; 95% CI 0.66–1.13) and median OS was 11 versus 12 months (HR 0.86, 95% CI 0.66–1.14).

Conclusion

Our results highlight a lack of clinical benefit by extending first line PE treatment in stage IV disease, and support limiting treatment to 4 cycles until superiority of a longer regimen is identified in a randomised study.

Post-progression survival is highly linked to overall survival in patients with non-small-cell lung cancer harboring sensitive EGFR mutations treated with first-line epidermal growth factor receptor-tyrosine kinase inhibitors

Background

In patients with epidermal growth factor receptor (EGFR)‐mutated advanced non‐small‐cell lung cancer (NSCLC), epidermal growth factor receptor‐tyrosine kinase inhibitor (EGFR‐TKI) treatment has shown a good response. Subsequent treatments jeopardize the ability to determine the effect of first‐line chemotherapy on overall survival (OS). Therefore, using patient‐level data, we aimed to study the associations of progression‐free survival (PFS) and post‐progression survival (PPS) with OS after first‐line EGFR‐TKI treatment in patients with EGFR‐mutated NSCLC.

Methods

Between November 2006 and December 2016, we analyzed 92 patients with EGFR‐mutated NSCLC treated with first‐line EGFR‐TKI. The correlations of PFS and PPS with OS were analyzed for each patient.

Results

Spearman's rank correlation and linear regression analyzes showed that PPS correlated highly with OS (r = 0.85, P < 0.05, R² = 0.75), whereas PFS correlated weakly with OS (r = 0.76, P < 0.05, R² = 0.50). The best responses after first‐line and second‐line treatments were significantly associated with PPS.

Conclusions

PPS has a higher impact on OS than PFS in patients with EGFR‐mutated NSCLC treated with first‐line EGFR‐TKIs. These outcomes suggest that the OS in this patient group may be affected by treatments following first‐line chemotherapy; however, this remains to be verified in prospective trials.

Real-world progression, treatment, and survival outcomes during rapid adoption of immunotherapy for advanced non-small cell lung cancer

BACKGROUND

Despite the rapid adoption of immunotherapies in advanced non-small cell lung cancer (advNSCLC), knowledge gaps remain about their real-world (rw) performance.

METHODS

This retrospective, observational, multicenter analysis used the Flatiron Health deidentified electronic health record-derived database of rw patients with advNSCLC who received treatment with PD-1 and/or PD-L1 (PD-[L]1) inhibitors before July 1, 2017 (N = 5257) and had ≥6 months of follow-up. The authors investigated PD-(L)1 line of treatment and PD-L1 testing rates and the relationship between overall survival (OS) and rw intermediate endpoints: progression-free survival (rwPFS), rw time to progression (rwTTP), rw time to next treatment (rwTTNT), and rw time to discontinuation (rwTTD).

RESULTS

First-line PD-(L)1 inhibitor use increased from 0% (in the third quarter of 2014 [Q3 2014]) to 42% (Q2 2017) over the study period. PD-L1 testing also increased (from 3% in Q3 2015 to 70% in Q2 2017). The estimated median OS was 9.3 months (95% CI, 8.9-9.8 months), and the estimated rwPFS was 3.2 months (95% CI, 3.1-3.3 months). Longer OS and rwPFS were associated with ≥50% PD-L1 percentage staining results. Correlations (⍴) between OS and intermediate endpoints were ⍴ = 0.75 (95% CI, 0.73-0.76) for rwPFS and ⍴ = 0.60 (95% CI, 0.57-0.63) for rwTTP, and, for treatment-based intermediate endpoints, correlations were ⍴ = 0.60 (95% CI, 0.56-0.64) for rwTTNT (N = 856) and ⍴ = 0.81 (95% CI, 0.80-0.82) for rwTTD.

CONCLUSIONS

The use of first-line PD-(L)1 inhibitors and PD-L1 testing has substantially increased, with better outcomes for patients who have ≥50% PD-L1 percentage staining. Intermediate rw tumor-dynamics estimates were moderately correlated with OS in patients with advNSCLC who received immunotherapy, highlighting the need for optimizing and standardizing rw endpoints to enhance the understanding of patient outcomes outside clinical trials.

Evaluation of classical clinical endpoints as surrogates for overall survival in patients treated with immune checkpoint blockers: a systematic review and meta-analysis

PURPOSE

Classical clinical endpoints [e.g., objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS)] may not be appropriate for immune checkpoint blockers (ICBs). We evaluated correlations between these endpoints and overall survival (OS) for surrogacy.

METHODS

Randomized controlled trials (RCTs) of solid tumors patients treated with ICBs published between 01/2005 and 03/2017, and congress proceedings (2014-2016) were included. Arm-level analyses measured 6-month PFS rate to predict 18-month OS rate. Comparison-level analyses measured ORR odds ratio (OR), DCR OR, and 6-month PFS hazard ratio (HR) to predict OS HR. A pooled analysis for single-agent ICBs and ICBs plus chemotherapy vs chemotherapy was conducted. Studies of single-agent ICBs vs chemotherapy were separately analyzed.

RESULTS

27 RCTs involving 61 treatment arms and 10,300 patients were included. Arm-level analysis showed higher 6- or 9-month PFS rates predicted better 18-month OS rates for ICB arms and/or chemotherapy arms. ICB arms had a higher average OS rate vs chemotherapy for all PFS rates. Comparison-level analysis showed a nonsignificant/weak correlation between ORR OR (adjusted R² = - 0.069; P = 0.866) or DCR OR (adjusted R² = 0.271; P = 0.107) and OS HR. PFS HR correlated weakly with OS HR in the pooled (adjusted R² = 0.366; P = 0.005) and single-agent (adjusted R² = 0.452; P = 0.005) ICB studies. Six-month PFS HR was highly predictive of OS HR for single-agent ICBs (adjusted R² = 0.907; P < 0.001), but weakly predictive in the pooled analysis (adjusted R² = 0.333; P = 0.023).

CONCLUSIONS

PFS was an imperfect surrogate for OS. Predictive value of 6-month PFS HR for OS HR in the single-agent ICB analysis requires further exploration.

Alternate Endpoints for Phase II Trials in Advanced Neuroendocrine Tumors

BACKGROUND

In phase II trials for neuroendocrine tumors (NETs), the objective response rate (ORR) is traditionally used as a primary endpoint. However, the validity of the ORR as a primary endpoint has never been systematically examined. Therefore, a literature-based analysis of phase II trials for NETs was performed to identify valid alternative endpoints for predicting median progression-free survival (PFS) in clinical trials for NETs.

MATERIALS AND METHODS

Phase II trials of medical treatment for advanced NETs were identified based on a systematic search using MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials.

RESULTS

A total of 22 trials were identified, and 1,310 patients and 27 treatment arms were included in the analysis. There was no significant relationship between the ORR and median PFS (r = .374; 95% confidence interval [CI], -0.051 to 0.800; p = .085). Conversely, 12-month PFS rates showed very strong correlations with median PFS (r = .929; 95% CI, 0.831-1.027; p < .001).

CONCLUSION

The results of the present analysis indicate that the ORR is not significantly correlated with median PFS and suggest that 12-month PFS rates are good alternate endpoints for screening phase II trials for NETs.

IMPLICATIONS FOR PRACTICE

Phase II trials are screening trials that seek to identify agents with sufficient activity to continue development. Thus, earlier endpoints are preferable, and the objective response rate (ORR) has been traditionally used as a surrogate endpoint in phase II trials for neuroendocrine tumors (NETs). However, the present study showed that the ORR was not significantly correlated with median progression-free survival (PFS). On the other hand, the 12-month PFS rate showed very strong correlation with median PFS and is considered a good alternate endpoint for screening phase II trials for NETs.

Immune checkpoint inhibitors and small cell lung cancer: what's new?

Despite extensive research no meaningful progress in systemic treatment of small cell lung cancer (SCLC) has been made in the past decades. Earlier attempts with immunotherapy including interferon and vaccination approaches had limited success. High mutational load, smoking history and potentially also the frequent presence of paraneoplastic phenomena-indicating an activated immune system-represent a rationale for a benefit from immune checkpoint inhibitors in SCLC. However, the likelihood of response is diminished due to poor T-cell activation resulting from low expression of MHC class I antigens, low amounts of tumor infiltrating lymphocytes (TILs) and low PD-L1 expression rates. Recently, early reports from studies with checkpoint inhibitors have shown promising results with the potential for long term disease control in a subset of SCLC patients. However, reliable predictive biomarkers to better define the population drawing most benefit are currently lacking. Results from ongoing phase III trials in different treatment lines and in the maintenance setting are eagerly awaited.

The effect of post-progression survival on overall survival among patients with sensitive relapse of small cell lung cancer

Recent studies have suggested that, among patients with advanced lung cancer, subsequent treatment after failure of first-line or second-line chemotherapy has a greater effect on overall survival (OS) than tumor shrinkage or progression-free survival (PFS). However, no studies have examined this issue among patients with sensitive relapse of small cell lung cancer (SCLC). We retrospectively evaluate 77 patients with sensitive relapse of SCLC who received second-line chemotherapy after first-line platinum doublet chemotherapy between January 1999 and November 2013. The analyses included patient characteristics, treatment parameters, tumor shrinkage, PFS, post-progression survival (PPS), and OS. Spearman rank correlation analysis and linear regression analysis revealed that PPS was strongly correlated with OS (r = 0.91, p < 0.01, R² = 0.96), PFS was moderately correlated with OS (r = 0.58, p < 0.01, R² = 0.28), and tumor shrinkage was weakly correlated with OS (r = 0.34, p < 0.01, R² = 0.12). A multivariate Cox proportional hazards model with a stepwise regression procedure revealed that PPS was significantly associated with age at the start of second-line chemotherapy, best response to second-line and third-line chemotherapy, and the number of regimens after progression beyond second-line chemotherapy (p < 0.05). These findings suggest that PPS has a stronger effect than PFS on OS among patients with sensitive relapse of SCLC. Thus, response to second-line chemotherapy and subsequent treatment for disease progression after second-line chemotherapy may be important factors that influence OS.

Perspective on the interpretation of research and translation to clinical care with therapy-associated metastatic breast cancer progression as an example

This commentary was written as a collaboration between the Board of the Metastasis Research Society and two patients with metastatic breast cancer. It was conceived in response to how preclinical scientific research is sometimes presented to non-scientists in a way that can cause stress and confusion. Translation of preclinical findings to the clinic requires overcoming multiple barriers. This is irrespective of whether the findings relate to exciting responses to new therapies or problematic effects of currently used therapies. It is important that these barriers are understood and acknowledged when research findings are summarized for mainstream reporting. To minimize confusion, patients should continue to rely on their oncology care team to help them interpret whether research findings presented in mainstream media have relevance for their individual care. Researchers, both bench and clinical, should work together where possible to increase options for patients with metastatic disease, which is still in desperate need of effective therapeutic approaches.

Somatostatin receptor expression in small cell lung cancer as a prognostic marker and a target for peptide receptor radionuclide therapy

Despite initial responsiveness to both chemotherapy and radiotherapy, small cell lung cancer (SCLC) commonly relapses within months. Although neuroendocrine characteristics may be difficult to demonstrate in individual cases, a relevant expression of somatostatin receptors (SSTR) on the cell surface has been described. We aimed to evaluate the prognostic value of SSTR-expression in advanced SCLC. We further examined pre-requisites for successful peptide receptor radionuclide therapy (PRRT).

21 patients with extensive stage SCLC were enrolled. All patients underwent positron emission tomography/computed tomography (PET/CT) with ⁶⁸Ga-DOTATATE to select patients for SSTR-directed therapy. PET scans were visually and semi-quantitatively assessed and compared to SSTR2a and SSTR5 expression in biopsy samples. Peak standardized uptake values (SUV_peak) of tumors as well as tumor-to-liver ratios were correlated to progression-free (PFS) and overall survival (OS).

In 4/21 patients all SCLC lesions were PET-positive. 6/21 subjects were rated “intermediate” with the majority of lesions positive, the remaining 11/21 patients were PET-negative. PET-positivity correlated well with histologic SSTR2a, but not with SSTR5 expression. Neither PET-positivity nor SUV_peak were predictors of PFS or OS. In 4 patients with intensive SSTR2a-receptor expression, PRRT was performed with one partial response and one stable disease, respectively.

SSTR-expression as detected by ⁶⁸Ga-DOTATATE-PET and/or histology is not predictive of PFS or OS in patients with advanced SCLC. However, in patients exhibiting sufficient tracer uptake, PRRT might be a treatment option given its low toxicity and the absence of effective alternatives.

Addition of oxaliplatin to capecitabine-based preoperative chemoradiotherapy for locally advanced rectal cancer: Long-term outcome of a phase II study

Our previous study reported the favorable short-term outcome and good tolerance of integrating oxaliplatin into capecitabine-based (XELOX regimen) preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). The present study reported the long-term oncological outcome of this phase II study. A total of 47 patients with rectal adenocarcinoma (stage II or III) were enrolled and received radiotherapy (46 Gy in 23 fractions) in combination with capecitabine (1,000 mg/m², twice daily, on days 1–14 and 22–35) and oxaliplatin (130 mg/m² on days 1 and 22). Overall survival (OS) rate, disease-free survival (DFS) rate and cumulative incidence of recurrences and long-term complications were calculated or observed. As a result, 41 patients underwent surgery after preoperative CRT, and the cumulative OS rates at 1, 3 and 5 years for these patients were 100.0, 84.5 and 81.8%, respectively. For the 38 patients who received R0 resection, the cumulative OS rates at 1, 3 and 5 years were 100.0, 89.0 and 86.2%, respectively, while the cumulative DFS rates at 1, 3 and 5 years were 94.6, 75.3 and 69.7%, respectively. After follow-up at 84 months, the cumulative incidence rates of local and distant recurrences at 5 years were 6.6 and 28.2%, respectively. Oxaliplatin-associated long-term complications were seldom observed. Overall, the addition of oxaliplatin to capecitabine-based preoperative radiotherapy achieved favorable OS and DFS without increased long-term complications in patients with LARC. Therefore, this preoperative CRT strategy is a feasible option for such patients.

Clinical predictors of survival in young patients with small cell lung cancer: Results from the California Cancer Registry

BACKGROUND

Small cell lung cancer (SCLC) is an often lethal disease that commonly occurs in older individuals with a history of heavy tobacco use. Limited epidemiologic and outcomes data are available on young SCLC patients aged less than 50 years of age. We assessed clinical variables related to cause specific survival (CSS) of young patients with SCLC.

METHODS

SCLC patients in the California Cancer Registry diagnosed between 1998 and 2012 were included. Primary outcome measure was CSS. Hazard ratios (HR) for CSS were calculated using Cox Proportional Hazards (pH) models for all ages & for patients <50 years, adjusted for baseline variables: age, gender, stage, race, year of diagnosis, initial treatment, socioeconomic status (SES), and location (urban vs. rural).

RESULTS

We identified 22,863 SCLC patients, of which 975 were less than 50 years of age (4.2%). Most patients <50years of age were male (51%), white race (71%), and had stage IV disease (60%). A lower proportion of patients aged 50 years or younger was diagnosed in later years: from 40% in 1998-2002 to 24% in 2008-2012. For all SCLC patients, age less than 50 years was an independent predictor of improved CSS (HR=0.82, p<0.0001). Multivariate Cox pH models showed that in younger patients, female sex (HR=0.81, p=0.0045), Asian race (HR=0.57, p=0.0075), and rural residence (HR=0.75, p=0.042) were associated with better CSS, among other variables.

CONCLUSIONS

In patients with SCLC, age less than 50 years was an independent predictor of improved CSS. Baseline clinical variables associated with better CSS were identified. These results have potential clinical applications.

Progression-Free Survival and Time to Progression as Real Surrogate End Points for Overall Survival in Advanced Breast Cancer: A Meta-Analysis of 37 Trials

BACKGROUND

Progression-free survival (PFS) and time to progression (TTP) have been reported to correlate with overall survival (OS) in several cancer types. To our knowledge, however, the correlation between them is unclear.

METHODS

A literature-based meta-analysis was performed to assess whether PFS and TTP can be considered reliable surrogate end points for OS in a phase 3 clinical trial of advanced breast cancer (ABC). The median hazard ratios of PFS/TTP and OS were analyzed by determining their nonparametric Spearman rank correlation coefficients (Rs).

RESULTS

A total of 37 trials with 38 treatment arms and 14,966 patients were selected for analysis. The Rs between the median PFS/TTP and OS was 0.405 (95% confidence interval [CI], 0.191-0.582; P = .003), and the correlation coefficient between the hazard ratios of PFS/TTP and OS was 0.555 (95% CI, 0.277-0.748; P = .003). PFS/TTP was closely correlated with OS in the trials of targeted therapy-based treatment (Rs = 0.872; 95% CI, 0.619-0.962; P = .0001) and of PFS/TTP or OS benefit (Rs = 0.753 and Rs = 0.821, respectively) for ABC.

CONCLUSIONS

Both PFS and TTP can be considered valid surrogate end points for OS in the trials of targeted therapy-based treatments and clinical benefits for ABC. Further research is necessary to clarify the surrogacy of PFS/TTP for OS in other trials of targeted therapy-based treatments for ABC.

Clinical significance of post-progression survival in lung cancer

Progression-free survival (PFS) and overall survival (OS) are two common endpoints in cancer trials. OS is usually preferred, because it is reliable, precise, meaningful, and can easily be documented. However, subsequent lines of therapy might confound the effects of first-line treatment on OS. Whether PFS or OS is the more appropriate endpoint in clinical trials of metastatic cancer remains controversial. Previous reports on lung cancer have shown that an increase in PFS does not necessarily result in an increase in OS; however, post-progression survival (PPS) is strongly associated with OS after early-line treatment. The significance of PPS after first and second-line therapy at the individual level in patients with advanced lung cancer has also recently been reported. Findings of previous reports indicate that PPS is highly associated with OS after first and second-line chemotherapy in patients with advanced non-small cell lung cancer and small cell lung cancer, whereas PFS is only moderately associated with OS. Therefore, subsequent treatment after disease progression following early-line treatments may greatly influence OS. This review demonstrates that even in advanced lung cancer, PPS, rather than PFS, has become more strongly associated with OS over the years, potentially because of intensive post-study treatments. As a result of the increasing impact of PPS on OS, a PFS-related advantage does not necessarily indicate an OS-related advantage. Thus, the prolongation of PPS might limit the classical role of OS for assessing true efficacy derived from early-line chemotherapy in future clinical trials.

Objective response rate is a possible surrogate endpoint for survival in patients with advanced, recurrent ovarian cancer

OBJECTIVE

Evaluate literature to assess response rate as a surrogate endpoint of survival in ovarian cancer (OC).

METHODS

Systematic review consistent with PRISMA criteria, identified randomized, controlled trials reporting overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) in recurrent OC. MEDLINE® and Embase® searches (year 2000-March 23, 2015) were augmented by bibliographic screening. Proposed surrogate measures (independent variables) were ORR and disease control rate. True clinical outcomes (dependent variables) were median OS and PFS. Analyses were performed on unweighted and weighted data using correlation analysis, linear regression, and surrogate threshold effect (STE). Smaller STE indicates greater predictive precision with magnitude of STE dependent on variance of prediction.

RESULTS

Thirty-nine studies were included for review, representing 9223 platinum-sensitive and resistant patients. Objective response rate (r=0.82; P<0.001) was a better predictor than disease control rate (r=0.58; P<0.001) and strongly correlated with PFS (r=0.85; P<0.0001). Weighted-regression analysis demonstrated that for each 10% increase in ORR, PFS increased by 1.20months and OS by 2.83months. Regression analysis of treatment effects (odds ratio of response, hazard ratio of survival) suggests that a 10% increase in odds ratio of ORR would result in 2.5% reduction in the hazard ratio of OS. Based on weighted data, STE indicated that an ORR of ≥1% is needed to achieve nonzero OS benefit.

CONCLUSION

This systematic review supports ORR as a possible surrogate clinical trial endpoint for OS in recurrent OC with at least second-line therapy.

[68Ga]Pentixafor-PET/CT for imaging of chemokine receptor 4 expression in small cell lung cancer--initial experience

Chemokine receptor CXCR4 is a key factor for tumor growth and metastasis in several types of human cancer. This study investigated the feasibility of CXCR4-directed imaging of small cell lung cancer (SCLC) with positron emission tomography/computed tomography (PET/CT) using the radiolabelled chemokine ligand [⁶⁸Ga]Pentixafor.

10 patients with primarily diagnosed (n=3) or pre-treated (n=7) SCLC (n=9) or large cell neuroendocrine carcinoma of the lung (LCNEC, n=1) underwent [⁶⁸Ga]Pentixafor-PET/CT. 2-[¹⁸F]fluoro-2-deoxy-D-glucose ([¹⁸F]FDG, n=6) and/or somatostatin receptor (SSTR)-directed PET/CT with [⁶⁸Ga]DOTATOC (n=5) and immunohistochemistry (n=10) served as standards of reference.

CXCR4-PET was positive in 8/10 patients and revealed more lesions with significantly higher tumor-to-background ratios than SSTR-PET. Two patients who were positive on [¹⁸F]FDG-PET were missed by CXCR4-PET, in the remainder [⁶⁸Ga]Pentixafor detected an equal (n=2) or higher (n=2) number of lesions. CXCR4 expression of tumor lesions could be confirmed by immunohistochemistry.

Non-invasive imaging of CXCR4 expression in SCLC is feasible. [⁶⁸Ga]Pentixafor as a novel PET tracer might serve as readout for confirmation of CXCR4 expression as prerequisite for potential CXCR4-directed treatment including receptor-radio(drug)peptide therapy.

Tumor invasion and metastasis regulated by microRNA-184 and microRNA-574-5p in small-cell lung cancer

Small-cell lung cancer (SCLC) is a highly aggressive neuroendocrine tumor that has an extremely poor clinical prognosis. Metastasis is the key event in SCLC progression, but its mechanism has not been fully elucidated. MicroRNAs (miRNAs) have been proven to participate in cancer processes, but their function in SCLC has not been thoroughly studied either. Here, we performed microarray and quantitative real-time PCR (qRT-PCR) analysesto identify the miRNAsassociated with metastasis and prognosis in SCLC as well as the correlation between serum and tissue. We also explored these miRNAs' promising molecular mechanisms by 3′UTR reporter assay and immunoblotting. We showed thatmiR-184 significantly attenuated the metastasis of SCLC, whereas miR-574–5p enhanced it. Both miRNAs were found to participate in β-catenin signaling by suppressing protein tyrosine phosphatase receptor type U (PTPRU)orendothelial PAS domain protein 1 (EPAS1). Furthermore, miR-574–5p was verified as an independent prognostic risk factor for SCLC. Taken together, our findings providea comprehensive analysis of the miRNA expression pattern in SCLC and indicate that miRNAs may serve as potential therapeutic and prognostic predictors in SCLC.