Progression-free survival and overall survival in phase III trials of molecular-targeted agents in advanced non-small-cell lung cancer

Modeling Overall Survival in Patients With Pancreatic Cancer From a Pooled Analysis of Phase II Trials

BACKGROUND

We evaluated the validity of surrogacy of progression-free survival (PFS) or time-to-progression (TTP) and overall response rate (ORR) in phase II trials of pancreatic ductal adenocarcinoma (PDAC). In addition, we explored the impact of predictive variables on overall survival (OS) and developed an optimal OS model.

METHODS

We analyzed 1867 clinical endpoint from 619 phase II PDAC trials with a systematic search from PubMed. Endpoint correlations were determined by Spearman's rank correlation. The assessed predictive factors included PFS/TTP, treatment size, therapy type, stage, and previous treatment. The relationship between predictors and OS was explored by a gamma generalized linear model (GLM) with a log-link function and compared with linear models.

RESULTS

The Spearman rank correlation coefficient between PFS/TTP and OS was 0.88 (95% confidence interval [CI] 0.85-0.89; p < 0.0001; n = 610) and between ORR and OS was 0.58 (0.52-0.64; p < 0.0001; n = 514). Model comparison favored the GLM model over the linear model, offering more accurate predictions for higher OS values. Consequently, PFS/TTP was the strongest predictor (pseudo-R2 = 0.75), with 1 added median PFS/TTP month associated with 13% (95% CI 13%-14%) increase in median OS. Subgroup analysis revealed that chemotherapy conferred significantly longer OS compared to targeted therapy in 1-Agent and 2-Agent trials, exhibiting a "very large" and "medium" effect size, respectively (rank biserial, rrb = 0.40 [95% CI 0.22-0.56] and rrb = 0.29 [0.16-0.41], both p < 0.0001), although inconsistent efficacy in 3-Agent trials (rrb = 0.12 [-0.07-0.30], p = 0.21).

CONCLUSIONS

PFS/TTP is a more reliable surrogate than ORR and a strong predictor of OS in phase II trials of pancreatic cancer. Moreover, gamma GLM (log-link function) is a robust tool for modeling positively skewed survival data with non-constant variance, thus can be applied to other cancers' OS data of such nature.

Real-World Pattern of Treatment and Clinical Outcomes of EGFR-Mutant Non-Small Cell Lung Cancer in a Single Academic Centre in Quebec

The discovery of EGFR tyrosine kinase inhibitors (TKI) for the treatment of EGFR mutant (EGFRm) metastatic NSCLC is regarded as a landmark in lung cancer. EGFR-TKIs have now become a standard first-line treatment for EGFRm NSCLC. The aim of this retrospective cohort study is to describe real-world patterns of treatment and treatment outcomes in patients with EGFRm metastatic NSCLC who received EGFR-TKI therapy outside of clinical trials. One hundred and seventy EGFRm metastatic NSCLC patients were diagnosed and initiated on first-line TKI therapy between 2004 and 2018 at the Peter Brojde Lung Cancer Centre in Montreal. Following progression of the disease, 137 (80%) patients discontinued first-line treatment. Moreover, 80/137 (58%) patients received second-line treatment, which included: EGFR-TKIs, platinum-based, or single-agent chemotherapy. At the time of progression on first-line treatment, 73 patients were tested for the T790M mutation. Moreover, 30/73 (41%) patients were found to be positive for the T790M mutation; 62/80 patients progressed to second-line treatment and 20/62 were started on third-line treatment. The median duration of treatment was 11.5 (95% CI; 9.62–13.44) months for first-line treatment, and 4.4 (95% CI: 1.47–7.39) months for second-line treatment. Median OS from the time of diagnosis of metastatic disease was 23.5 months (95% CI: 16.9–30.1) and median OS from the initiation of EGFR-TKI was 20.6 months (95% CI: 13.5–27.6). We identified that ECOG PS ≤ 2, presence of exon 19 deletion mutation, and absence of brain metastases were associated with better OS. A significant OS benefit was observed in patients treated with osimertinib in second-line treatment compared to those who never received osimertinib. Overall, our retrospective observational study suggests that treatment outcomes in EGFRm NSCLC in real-world practice, such as OS and PFS, reflect the result of RCTs. However, given the few observational studies on real-world treatment patterns of EGFR-mutant NSCLC, this study is important for understanding the potential impact of EGFR-TKIs on survival outside of clinical trials. Further real-world studies are needed to characterize patient outcomes for emerging therapies, including first-line osimertinib use and combination of osimertinib with chemotherapy and potential future combination of osimertinib and novel anticancer drug, outside of a clinical trial setting.

Surrogate Endpoints in Oncology: Overview of Systematic Reviews and Their Use for Health Decision Making in Mexico

OBJECTIVES

The use of surrogate endpoints (SEs) for cancer drug approval in health systems is common. The objectives of this study were to identify systematic reviews (SRs) that evaluated the correlation of SEs with overall survival (OS) in cancer drugs to analyze the applications of approved cancer drugs with SEs in Mexico and to apply the validation framework proposed by the Institute for Quality and Efficiency in Health Care (IQWiG).

METHODS

An overview of SRs was conducted according to Cochrane Collaboration methodology. Applications for approved cancer drugs with SEs in Mexico were analyzed. The IQWiG validation framework was applied to evaluate the SEs identified in the overview and in the applications in Mexico.

RESULTS

A total of 85 SRs that assessed 192 SEs for different types of cancer were selected. According to the IQWiG model, only 2.5% of the SEs analyzed in the overview and only one of the applications in Mexico could be used as surrogates for OS because the reliability (methodological quality) of the SRs and the strength of the correlation of SEs with OS was mostly low (92%) and low (correlation coefficient r ≤ 0.7; 50.5%), respectively. Of the total number of cancer drugs approved in Mexico, 19.4% used SEs.

CONCLUSIONS

Most SEs for different types of cancer could not be used as surrogates for OS according to the IQWiG model, and their use for the approval of cancer drugs in Mexico is generally not justified.

Prognostic Impact of the Advanced Lung Cancer Inflammation Index (ALI) in Metastatic Non-Small Cell Lung Cancer Treated with First Line Chemotherapy

Background:

The advanced lung cancer inflammation index (ALI) has been reported to predict the overall survival in patients with advanced non-small cell lung cancer (NSCLC). However, no previous studies have examined the prognostic significance of ALI in metastatic NSCLC treated with first line chemotherapy. The objective of this study was to explore the relationship between ALI and the prognosis of metastatic NSCLC treated with first line chemotherapy.

Materials and Methods:

Data of 109 metastatic NSCLC patients who had completed first line treatment with chemotherapy was collected. A multivariate flexible parametric proportional-hazards model with restricted cubic splines (RCS) was used to explore and identify the independent prognostic factors, including clinical potential factors and ALI for the overall survival. Multivariate regression analysis was used to evaluate the potential prognostic factors associated with short survival less than 6 months. The analysis of the restricted mean survival time (RMST) method was used to estimate the event-free time from zero to 18 months.

Results:

The median OS was 10.9 months (95%CI 9.57-13.18) and median PFS was 7.5 months (95%CI 6.85-8.00).The multivariate survival analyses revealed two prognostic factors for worse survival: Poor ECOG PS (HR46.90; 95%CI 2.90-758.73; p=0.007) and progressive disease after completing the first line chemotherapy treatment (HR 2.85; 95%CI1.18-6.88; p=0.02),whereas a low ALI <11 referred to a non-significant prognostic factor (HR 1.42; 95%CI 0.67-3.01; p=0.364).The results of the multivariate regression analysis revealed that the low ALI and progressive disease status were significantly associated with the short survival outcome (OR 5.12; 95%CI 1.11-23.65; p=0.037; OR 12.57; 95%CI 3.00-52.73; p=0.001).

Conclusions:

A low ALI was associated with the short survival in metastatic NSCLC treated with chemotherapy. However, using ALI as a prognostic factor only was still too limited. Other considerable clinical prognostic factors should also be used simultaneously, which would have strong significant prognostic impacts.

Impact of Advantage in Tumor Response on the Correlation Between Progression-Free Survival and Overall Survival: Meta-Analysis of Clinical Trials in Patients with Advanced Non-Small Cell Lung Cancer

BACKGROUND

Progression-free survival (PFS) has not been validated as a surrogate endpoint for overall survival (OS) in patients with advanced non-small cell lung cancer.

OBJECTIVE

This study aimed to investigate an impact of advantage in tumor response on the correlation between PFS and OS in advanced non-small cell lung cancer.

METHODS

Based on a literature search, we identified randomized controlled trials of first-line therapy for advanced non-small cell lung cancer. The impact of absolute difference in objective response rate between treatment arms on the correlation between hazard ratios (HRs) for PFS and OS was evaluated based on Spearman rank correlation coefficients.

RESULTS

Sixty trials with a total of 29,134 patients were identified. The HR for PFS showed a relatively higher correlation with HR for OS (r_s = 0.75) when the trials were limited to those that demonstrated a larger advantage in objective response rate, compared with the case for trials that demonstrated a smaller advantage (r_s = 0.66). This tendency was also observed in the subgroup analysis stratified by the types of treatment agents (non-targeted, anti-angiogenic, and immunotherapy) except for the group of epidermal growth factor receptor-targeted agents.

CONCLUSIONS

The magnitude of advantage in tumor response was suggested to contribute to a better prediction of OS-HR based on PFS-HR in clinical trials in patients with advanced non-small cell lung cancer.

Trends in Phase II Trials for Cancer Therapies

Background: Drug combinations are the standard of care in cancer treatment. Identifying effective cancer drug combinations has become more challenging because of the increasing number of drugs. However, a substantial number of cancer drugs stumble at Phase III clinical trials despite exhibiting favourable efficacy in the earlier Phase. Methods: We analysed recent Phase II cancer trials comprising 2165 response rates to uncover trends in cancer therapies and used a null model of non-interacting agents to infer synergistic and antagonistic drug combinations. We compared our latest efficacy dataset with a previous dataset to assess the progress of cancer therapy. Results: Targeted therapies reach higher response rates when used in combination with cytotoxic drugs. We identify four synergistic and 10 antagonistic combinations based on the observed and expected response rates. We demonstrate that recent targeted agents have not significantly increased the response rates. Conclusions: We conclude that either we are not making progress or response rate measured by tumour shrinkage is not a reliable surrogate endpoint for the targeted agents.

A Phase III, randomized, double-blind, placebo-controlled, multicenter study of fruquintinib in Chinese patients with advanced nonsquamous non-small-cell lung cancer - The FALUCA study

OBJECTIVES

Fruquintinib is an orally active kinase inhibitor that selectively targets the vascular endothelial growth factor (VEGF) receptor. A Phase II trial has demonstrated a significant benefit in progression-free survival (PFS) for fruquintinib-treated patients with locally advanced/metastatic nonsquamous non-small-cell lung cancer (NSCLC) who have progressed after second-line chemotherapy. This Phase III trial is a randomized, double-blind, multicenter trial to confirm fruquintinib's efficacy in the same patient population.

MATERIALS AND METHODS

From December 2015 to February 2018, 730 patients were screened, of whom 527 were enrolled into the study. Participants were randomized 2:1 to receive fruquintinib (n = 354) or placebo (n = 173) once daily for 3 weeks on-treatment, and 1 week off-treatment. Patients were stratified according to epidermal growth factor receptor mutation status and prior use of VEGF inhibitors. Primary endpoint was overall survival (OS).

RESULTS

Median OS was 8.9 months for the fruquintinib group and 10.4 months for placebo group (hazard ratio [HR] 1.02; 95 % confidence interval [CI], 0.82-1.28; P = 0.841), with median PFS of 3.7 months and 1.0 months, respectively (HR 0.34; 95 % CI, 0.28-0.43; P < 0.001). Objective response rate and disease control rate were 13.8 % and 66.7 % for fruquintinib, and 0.6 % and 24.9 % for placebo, respectively (P < 0.001). Hypertension was the most frequent treatment-emergent adverse event (≥grade 3) observed in fruquintinib-treated patients (21.0 %). Post hoc analysis revealed that fruquintinib prolonged the median OS for patients who did not receive subsequent antitumor therapy: 7.0 months versus 5.1 months for placebo (HR 0.65; 95 % CI, 0.46-0.91; P = 0.012). Patients receiving fruquintinib also reported improvements in quality of life for most functional scales measured by EORTC QLQ-C30 and LC13 questionnaires.

CONCLUSION

Although the study did not meet its primary endpoint, fruquintinib could be effective in combination with other agents for the treatment of patients with NSCLC who have failed second-line chemotherapy.

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.

Progression-free survival and one-year milestone survival as surrogates for overall survival in previously treated advanced non-small cell lung cancer

The advent of immunotherapy leads to greater availability of effective subsequent treatments and extended survival in previously treated advanced non-small cell lung cancer (NSCLC), complicating the evaluation of overall survival (OS) in second-line NSCLC trials. Here, we aimed to assess the surrogacy of progression-free survival (PFS) and milestone survival for OS in second-line NSCLC trials investigating chemotherapy, targeted therapy and immunotherapy, respectively. We systemically searched for active-controlled, second-line NSCLC trials. The milestone time point was set at one-year based on pre-analysis. A two-stage meta-analytic validation model was adopted to assess associations between surrogate endpoint (SE) and OS and associations between treatment effects on SE and OS. Treatment effects on SE and OS were expressed as PFS hazard ratios (HR_PFS ), 1 yr-milestone ratio (Ratio_1y-SUR ) and HR_OS . Subgroup analyses stratified by treatment types and trial publication years evaluated the surrogacy in different clinical contexts. The study included 50 trials with 22,804 patients. One-year survival strongly correlated with OS (R² [95% confidence interval]: one-year survival -median OS = 0.707 [0.704-0.708]; Ratio_1y-SUR -HR_OS = 0.829 [0.828-0.831]). No correlation was established between PFS and OS (median PFS-median OS = 0.100 [0.098-0.101]; HR_PFS -HR_OS = 0.064 [0.059-0.069]), except in immunotherapy subgroup (HR_PFS -HR_OS = 0.835 [0.791-0.918]). In subgroup analyses, surrogacy of one-year survival persisted in different clinical contexts, and the disassociation between PFS and OS persisted in recent trials. One-year milestone survival showed strong surrogacy for OS in second-line NSCLC trials. Although no association was identified between PFS and OS, the strong HR_PFS -HR_OS correlation in immunotherapy trials indicates the potential of PFS as a SE in NSCLC trials involving immunotherapies.

The impact of high PD-L1 expression on the surrogate endpoints and clinical outcomes of anti-PD-1/PD-L1 antibodies in non-small cell lung cancer

BACKGROUND

Recent reports have indicated that the objective response rate (ORR) and progression-free survival (PFS) cannot serve as surrogates for predicting overall survival (OS) in immune checkpoint inhibitor (ICI) trials. We performed a trial-based correlative analysis to evaluate conventional endpoints as surrogates for predicting OS in ICI-treated non-small cell lung cancer (NSCLC) patients.

METHODS

A systematic electronic literature search for randomized clinical trials using ICI monotherapies for NSCLC revealed 7 trials. The correlative analysis to clarify the correlations among clinical outcomes used a weighted Spearman rank correlation coefficient (wS), weighted Pearson correlation coefficient (wP), and weighted linear regression model (wL) in all patients and patients with high PD-L1 expression.

RESULTS

The correlative analysis of the total population revealed that the odds ratio of the ORR (OR-ORR) and the hazard ratio of OS (HR-OS) were strongly correlated with the hazard ratio of PFS (HR-PFS) (R for wP and wS, R² for wL; -0.869, -0.968, 0.756 between OR-ORR and HR-PFS; 0.923, 0.959, 0.851 between HR-PFS and HR-OS). The strongest correlation was observed between one-year overall survival (1y-OS) and the HR-OS (R for wP and wS, R² for wL; 0.985, 1.000, R²: 0.968). In those with high PD-L1 expression, the ORR and PFS were strongly associated with OS (R²: 0.842 between ORR and OS; 0.771 between PFS and OS).

CONCLUSIONS

The OR-ORR and HR-PFS could serve as surrogate endpoints for predicting the HR-OS in randomized trials using ICIs for NSCLC, while the ORR and PFS could be useful endpoints for predicting OS in trials with patient selection based on high PD-L1 expression.

CHALLENGES AND METHODOLOGIES IN USING PROGRESSION FREE SURVIVAL AS A SURROGATE FOR OVERALL SURVIVAL IN ONCOLOGY

OBJECTIVES

A primary outcome in oncology trials is overall survival (OS). However, to estimate OS accurately requires a sufficient number of patients to have died, which may take a long time. If an alternative end point is sufficiently highly correlated with OS, it can be used as a surrogate. Progression-free survival (PFS) is the surrogate most often used in oncology, but does not always satisfy the correlation conditions for surrogacy. We analyze the methodologies used when extrapolating from PFS to OS.

METHODS

Davis et al. previously reviewed the use of surrogate end points in oncology, using papers published between 2001 and 2011. We extend this, reviewing papers published between 2012 and 2016. We also examine the reporting of statistical methods to assess the strength of surrogacy.

RESULTS

The findings from 2012 to 2016 do not differ substantially from those of 2001 to 2011: the same factors are shown to affect the relationship between PFS and OS. The proportion of papers reporting individual patient data (IPD), strongly recommended for full assessment of surrogacy, remains low: 33 percent. A wide range of methods has been used to determine the appropriateness of surrogates. While usually adhering to reporting standards, the standard of scholarship appears sometimes to be questionable and the reporting of results often haphazard.

CONCLUSIONS

Standards of analysis and reporting PFS to OS surrogate studies should be improved by increasing the rigor of statistical reporting and by agreeing to a minimum set of reporting guidelines. Moreover, the use of IPD to assess surrogacy should increase.

The changing face of clinical trials in the personalized medicine and immuno-oncology era: report from the international congress on clinical trials in Oncology & Hemato-Oncology (ICTO 2017)

In the past decade, the oncology community has witnessed major advances in the understanding of cancer biology and major breakthroughs in several different therapeutic areas, from solid tumors to hematological malignancies; moreover, the advent of effective immunotherapy approaches, such as immune-checkpoint blockade, is revolutionizing treatment algorithms in almost all oncology disease areas. As knowledge evolves and new weapons emerge in the “war against cancer”, clinical and translational research need to adapt to a rapidly changing environment to effectively translate novel concepts into sustainable and accessible therapeutic options for cancer patients.

With this in mind, translational cancer researchers, oncology professionals, treatment experts, CRO and industry leaders, as well as patient representatives gathered in London, 16-17 March 2017, for The International Congress on Clinical Trials in Oncology and Hemato-Oncology (ICTO2017), to discuss the changing face of oncology clinical trials in the new era of personalized medicine and immuno-oncology. A wide range of topics, including clinical trial design in immuno-oncology, biomarker-oriented drug development paths, statistical design and endpoint selection, challenges in the design and conduct of personalized medicine clinical trials, risk-based monitoring, financing and reimbursement, as well as best operational practices, were discussed in an open, highly interactive format, favoring networking among all relevant stakeholders. The most relevant data, approaches and issues emerged and discussed during the conference are summarized in this report.

Surrogate Endpoints in Second-Line Trials of Targeted Agents in Metastatic Colorectal Cancer: A Literature-Based Systematic Review and Meta-Analysis

PURPOSE

The purpose of this study was to evaluate progression-free survival (PFS) and objective response rate (ORR) as surrogate endpoints of overall survival (OS) in modern clinical trials investigating the efficacy of targeted agents in the second-line treatment of metastatic colorectal cancer (mCRC).

MATERIALS AND METHODS

A systematic search of literature pertaining to randomized phase II and III trials evaluating targeted agents as second-line treatments for mCRC was performed. The strength of the correlation between both PFS and ORR and OS was assessed based on the Pearson's correlation coefficient (R) and the coefficient of determination (R2).

RESULTS

Twenty trials, including a total of 7,571 patients, met the search criteria. The median duration of post-progression survival (PPS) was 7.6 months. The median differences between experimental and control arms were 0.65 months (range, -2.4 to 3.4) for the median PFS and 0.7 months (range, -5.8 to 3.9) for the median OS. PFS and ORR showed moderate (R=0.734, R2=0.539, p < 0.001) and poor correlation (R=0.169, R2=0.029, p=0.476) with OS, respectively. No differences between anti-angiogenic agents and other drugs were evident.

CONCLUSION

Targeted agents investigated in the second-line treatment of mCRC provided minimal PFS gains translating into modest OS improvements. Considering both the moderate correlation between PFS and OS and the short duration of PPS, the OS should remain the preferred primary endpoint for randomized clinical trials in the second-line treatment of mCRC.

Treatment Paradigms for Advanced Non-Small Cell Lung Cancer at Academic Medical Centers: Involvement in Clinical Trial Endpoint Design

Selection of appropriate clinical endpoints for examining the efficacy of investigational agents for non‐small cell lung cancer is of vital importance in clinical trial design. This review provides an overview of the study designs of clinical trials for approved agents in non‐small cell lung cancer and focuses on the validity of alternative endpoints for such trials.

Based on the positive results of various clinical trials, treatment options for non‐small cell lung cancer (NSCLC) have expanded greatly over the last 25 years. While regulatory approvals of chemotherapeutic agents for NSCLC have largely been based on improvements in overall survival, recent approvals of many targeted agents for NSCLC (afatinib, crizotinib, ceritinib, osimertinib) have been based on surrogate endpoints such as progression‐free survival and objective response. As such, selection of appropriate clinical endpoints for examining the efficacy of investigational agents for NSCLC is of vital importance in clinical trial design. This review provides an overview of clinical trial endpoints previously utilized for approved agents for NSCLC and highlights the key efficacy results for these trials. Trends for more recent approvals in NSCLC, including those for the immunotherapeutic agents nivolumab and pembrolizumab, are also discussed. The results of a correlative analysis of endpoints from 18 clinical trials that supported approvals of investigational agents in clinical trials for NSCLC are also presented.

Implications for Practice.

While improving survival remains the ultimate goal of oncology clinical trials, overall survival may not always be the most feasible or appropriate endpoint to assess patient response. Recently, several investigational agents, both targeted agents and immunotherapies, have gained U.S. Food and Drug Administration approval in non‐small cell lung cancer based on alternate endpoints such as progression‐free survival or response rate. An understanding of the assessment of response and trial endpoint choice is important for future oncology clinical trial design.

Relationship between Overall Survival and Response or Progression-Free Survival in Advanced Non-Small Cell Lung Cancer Patients Treated with Anti-PD-1/PD-L1 Antibodies

INTRODUCTION

Alternative predictive end points for overall survival (OS), such as tumor response and progression-free survival (PFS), are useful in the early detection of drug efficacy; however, they have not been fully investigated in patients with advanced NSCLC treated with anti-programmed death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) antibodies.

METHODS

In a systematic review of the reported prospective clinical trials, data for response rate, median PFS, and median OS were extracted from 12 arms in 10 reported clinical trials using anti-PD-1/PD-L1 antibody, and their correlation was investigated. In a retrospective analysis at our institution, OS was compared according to tumor response on 5- to 9-week computed tomography scans and status of being progression-free at 8, 16, and 24 weeks by landmark analysis in 71 patients with advanced NSCLC treated with anti-PD-1/PD-L1 antibodies between 2013 and 2015.

RESULTS

In a systematic review, moderate correlations between median OS and median PFS (p = 0.120, r = 0.473) and between median OS and response rate (p = 0.141, r = 0.452) were identified using the Spearman correlation coefficient, although these correlations were not statistically significant. In a retrospective analysis of patients treated at our institution, disease control (partial response [PR]/stable disease versus progressive disease/not evaluable), and progression-free status at 8, 16, and 24 weeks significantly predicted OS (Cox proportional hazards model, PR/stable disease versus progressive disease/not evaluable, p = 0.0104, HR = 3.041; 8-week progression-free yes versus no, p = 0.0183, HR = 2.684; 16-week progression-free yes versus no, p = 0.0036, HR = 4.009; and 24-week progression-free yes versus no, p = 0.0002, HR = 12.726).

CONCLUSIONS

Both disease control (PR plus stable disease status) and landmark progression-free survival were correlated with OS, with the longer interval landmark PFS being the best predictor of survival in patients with NSCLC treated with anti-PD-1/PD-L1 antibodies.

Progression-Free Survival, Response Rate, and Disease Control Rate as Predictors of Overall Survival in Phase III Randomized Controlled Trials Evaluating the First-Line Chemotherapy for Advanced, Locally Advanced, and Recurrent Non-Small Cell Lung Carcinoma

INTRODUCTION

Recent improvements in chemotherapy agents have prolonged postprogression survival of non-small cell lung cancer. Thus, primary outcomes other than overall survival (OS) have been frequently used for recent phase III trials to obtain quick results. However, no systematic review had assessed whether progression-free survival (PFS), response rate (RR), and disease control rate (DCR) can serve as surrogates for OS at the trial level in the phase III first-line chemotherapy setting.

METHODS

We included phase III randomized clinical trials (RCTs) comparing two arms that were reported as a full article regardless of their primary end point. We included only RCTs that evaluated chemonaive patients with advanced, locally advanced, or metastatic non-small cell lung cancer and were published after January 1, 2005. We systematically searched four public electronic databases. Two investigators independently screened and scrutinized candidate articles. How surrogate outcomes represented hazard ratios (HRs) for OS was examined.

RESULTS

Among 1907 articles, we ultimately found 44 eligible articles covering 22,709 subjects. HR for PFS, median PFS in the experimental arm minus median PFS in the control arm in months, OR for RR (ORrr), and OR for DCR were evaluated in 34, 35, 44, and 35 RCTs, respectively. HR for OS (HRos), median PFS in the experimental arm minus median PFS in the control arm, ORrr, and OR for DCR had weighted Spearman's rank correlation coefficients with an HRos of 0.496, 0.477, 0.570, and 0.470, respectively; the standardized weighted regression coefficients were 0.439, -0.376, -0.605, and -0.381, respectively; and the adjusted weighted coefficients of determination were 0.224, 0.161, 0.350, and 0.176, respectively.

CONCLUSIONS

ORrr, followed by HRpfs, had the strongest association with HRos at the trial level. However, these measures were not strong enough to replace OS.

Strength of Validation for Surrogate End Points Used in the US Food and Drug Administration's Approval of Oncology Drugs

OBJECTIVE

To determine the strength of the surrogate-survival correlation for cancer drug approvals based on a surrogate.

PARTICIPANTS AND METHODS

We performed a retrospective study of the US Food and Drug Administration (FDA) database, with focused searches of MEDLINE and Google Scholar. Among cancer drugs approved based on a surrogate end point, we examined previous publications assessing the strength of the surrogate-survival correlation. Specifically, we identified the percentage of surrogate approvals lacking any formal analysis of the strength of the surrogate-survival correlation, and when conducted, the strength of such correlations.

RESULTS

Between January 1, 2009, and December 31, 2014, the FDA approved marketing applications for 55 indications based on a surrogate, of which 25 were accelerated approvals and 30 were traditional approvals. We could not find any formal analyses of the strength of the surrogate-survival correlation in 14 out of 25 accelerated approvals (56%) and 11 out of 30 traditional approvals (37%). For accelerated approvals, just 4 approvals (16%) were made where a level 1 analysis (the most robust way to validate a surrogate) had been performed, with all 4 studies reporting low correlation (r≤0.7). For traditional approvals, a level 1 analysis had been performed for 15 approvals (50%): 8 (53%) reported low correlation (r≤0.7), 4 (27%) medium correlation (r>0.7 to r<0.85), and 3 (20%) high correlation (r≥0.85) with survival.

CONCLUSIONS

The use of surrogate end points for drug approval often lacks formal empirical verification of the strength of the surrogate-survival association.

Surrogate clinical endpoints to predict overall survival in non-small cell lung cancer trials-are we in a new era?

Surrogate endpoints for clinical trials in oncology offer an alternative metric for measuring clinical benefit, allowing for shorter trial duration, smaller patient cohorts, and single arm design. The correlation of surrogate endpoints with overall survival (OS) in therapeutic studies is a central consideration to their validity. The Food and Drug Administration (FDA) recently published an analysis of fourteen clinical trials in advanced non-small cell lung cancer (NSCLC), and discovered a strong association between response rate and progression free survival. Furthermore, a correlation between response rate and OS is demonstrated when analyzing the experimental treatment arm separately, minimizing bias from patient crossover. We also highlight multiple, important considerations when using response as an endpoint in clinical trials involving NSCLC patients.

Improved overall survival following tyrosine kinase inhibitor treatment in advanced or metastatic non-small-cell lung cancer-the Holy Grail in cancer treatment?

Advanced or metastatic non-small-cell lung cancer (NSCLC) is characterized by a poor prognosis and few second- or third-line treatments. First-generation epidermal growth factor receptor tyrosine kinase inhibition has paved the way for targeted therapies in lung cancer. Although these drugs result in excellent responses [and significantly improved progression-free survival (PFS)] in patients with activating EGFR mutations, none of these randomized studies has yet demonstrated a statistically significant improvement of overall survival (OS). PFS is often used as a predictor for improved OS since it is independent of subsequent treatment, but OS is acknowledged as the key clinical outcome in the treatment of advanced NSCLC. When effective treatment is given as post therapy, it will be difficult to distinguish the treatment effect of original and subsequent treatments because differences in OS are potentially confounded by crossover, and a relevant number of patients assigned to chemotherapy arms received tyrosine kinase inhibitors (TKIs) as second- or third-line treatment after disease progression. The high proportion of crossover may extend the benefit associated with the administration of TKIs to patients assigned to the control arm, and its "salvage"-effect may compensate for the relevant differences in PFS of first-line treatment consistently demonstrated in all TKI trials. Results for the INFORM trial (maintenance therapy with gefitinib following platinum-based chemotherapy) provided evidence that maintenance therapy with gefitinib significantly improved PFS, with greatest benefit in patients harboring EGFR mutation. Despite a high crossover rate (53%) final OS results of this study have now demonstrated a significant survival benefit for the gefitinib-treated EGFR mutation-positive patients (46.9 vs. 21.0 months, P=0.036). This is the first randomized clinical trial that showed a significant and clinical meaningful OS benefit in EGFR mutation-positive NSCLC patients following maintenance therapy with gefitinib as compared to placebo. It remains to be seen whether further exploration of this treatment strategy will confirm these promising results.

The efficacy and safety of pemetrexed-based doublet therapy compared to pemetrexed alone for the second-line treatment of advanced non-small-cell lung cancer: an updated meta-analysis

Background

Pemetrexed is currently recommended as the second-line treatment for patients with advanced non-small-cell lung cancer (NSCLC). However, it is unclear whether pemetrexed-based doublet therapy improves treatment efficacy and safety. Thus, this meta-analysis was performed to resolve this controversial question.

Methods

Electronic databases, including PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched for relevant articles before April 2015. Hazard ratios (HRs) were used to estimate overall survival (OS) and progression-free survival (PFS), and odds ratios (ORs) were used to analyze the overall response rate (ORR) and grade ≥3 toxicities. Subgroup analysis, sensitivity analysis, and publication bias were also evaluated.

Results

A total of 2,519 patients from ten randomized controlled trials were included. Compared to pemetrexed alone, PFS and ORR significantly improved in the pemetrexed-based doublet group (HR, 0.86; 95% CI [confidence interval], 0.75–0.99; P=0.038; and OR, 1.98; 95% CI, 1.25–3.12; P=0.003, respectively). However, no statistically significant differences in OS were observed between groups (HR, 0.92; 95% CI, 0.83–1.02; P=0.132). In addition, subgroup analyses indicated that improved OS was only observed in nonsquamous NSCLC patients who received the combination of pemetrexed and erlotinib. An increasing incidence of grade ≥3 neutropenia and thrombocytopenia was observed in the pemetrexed-based doublet group.

Conclusion

Among patients with advanced NSCLC, pemetrexed-based doublet treatment tended to be associated with improved PFS, ORR, and increased toxicity, but not OS.

Lung Master Protocol (Lung-MAP)-A Biomarker-Driven Protocol for Accelerating Development of Therapies for Squamous Cell Lung Cancer: SWOG S1400

The Lung Master Protocol (Lung-MAP, S1400) is a groundbreaking clinical trial designed to advance the efficient development of targeted therapies for squamous cell carcinoma (SCC) of the lung. There are no approved targeted therapies specific to advanced lung SCC, although The Cancer Genome Atlas project and similar studies have detected a significant number of somatic gene mutations/amplifications in lung SCC, some of which are targetable by investigational agents. However, the frequency of these changes is low (5%-20%), making recruitment and study conduct challenging in the traditional clinical trial setting. Here, we describe our approach to development of a biomarker-driven phase II/II multisubstudy "Master Protocol," using a common platform (next-generation DNA sequencing) to identify actionable molecular abnormalities, followed by randomization to the relevant targeted therapy versus standard of care.

Magnitude of the benefit of progression-free survival as a potential surrogate marker in phase 3 trials assessing targeted agents in molecularly selected patients with advanced non-small cell lung cancer: systematic review

Background

In evaluation of the clinical benefit of a new targeted agent in a phase 3 trial enrolling molecularly selected patients with advanced non-small cell lung cancer (NSCLC), overall survival (OS) as an endpoint seems to be of limited use because of a high level of treatment crossover for ethical reasons. A more efficient and useful indicator for assessing efficacy is needed.

Methods and Findings

We identified 18 phase 3 trials in the literature investigating EGFR-tyrosine kinase inhibitor (TKIs) or ALK-TKIs, now approved for use to treat NSCLC, compared with standard cytotoxic chemotherapy (eight trials were performed in molecularly selected patients and ten using an “all-comer” design). Receiver operating characteristic analysis was used to identify the best threshold by which to divide the groups. Although trials enrolling molecularly selected patients and all-comer trials had similar OS-hazard ratios (OS-HRs) (0.99 vs. 1.04), the former exhibited greater progression-free survival-hazard ratios (PFS-HR) (mean, 0.40 vs. 1.01; P<0.01). A PFS-HR of 0.60 successfully distinguished between the two types of trials (sensitivity 100%, specificity 100%). The odds ratio for overall response was higher in trials with molecularly selected patients than in all-comer trials (mean: 6.10 vs. 1.64; P<0.01). An odds ratio of 3.40 for response afforded a sensitivity of 88% and a specificity of 90%.

Conclusion

The notably enhanced PFS benefit was quite specific to trials with molecularly selected patients. A PFS-HR cutoff of ∼0.6 may help detect clinical benefit of molecular targeted agents in which OS is of limited use, although desired threshold might differ in an individual trial.

Meta-analysis of EGFR tyrosine kinase inhibitors compared with chemotherapy as second-line treatment in pretreated advanced non-small cell lung cancer

BACKGROUND

Since efficacy and safety of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) versus chemotherapy in the treatment of patients with pretreated advanced non-small cell lung cancer (NSCLC) remain controversial, we performed a meta-analysis to compare them.

METHODS

An internet search of several databases was performed, including PubMed, Embase, and the Cochrane database. Randomized trials that compared an EGFR-TKI with chemotherapy in the second-line setting were included. The outcomes were progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and grade 3-4 toxicities. The PFS, OS for the EGFR mutation-positive (EGFR M+) and EGFR mutation-negative (EGFR M-) subgroups were pooled. The pooled hazard ratios (HRs) and odds ratios (ORs) with their corresponding confidence intervals (CIs) were calculated on the STATA software.

RESULTS

Our meta-analysis combined 3,825 patients from 10 randomized trials. Overall, EGFR-TKIs and second-line chemotherapy have equivalent efficacy in terms of PFS (HR, 1.03; 95%CI, 0.87-1.21; P = 0.73; I2 = 78.7%, Pheterogeneity<0.001), OS (HR, 1.00; 95%CI, 0.92-1.08; P = 0.90; I2 = 0.0%, Pheterogeneity = 0.88), and ORR (OR, 1.34; 95%CI, 0.86-2.08; P = 0.20; I2 = 73.1%, Pheterogeneity<0.001). However, subgroup analysis based on EGFR mutation status showed that second-line chemotherapy significantly improved PFS (HR, 1.35; 95%CI, 1.09-1.66; P = 0.01; I2 = 55.7%, Pheterogeneity = 0.046) for EGFR M- patients, whereas OS was equal (HR, 0.96; 95%CI, 0.77-1.19; P = 0.69; I2 = 0.0%, Pheterogeneity = 0.43); EGFR-TKIs significantly improved PFS (HR, 0.28; 95%CI, 0.15-0.53; P<0.001; I2 = 4.1%, Pheterogeneity = 0.35) for EGFR M+ patients, whereas OS was equal (HR, 0.86; 95%CI, 0.44-1.68; P = 0.65; I2 = 0.0%, Pheterogeneity = 0.77). Compared with chemotherapy, EGFR-TKIs led to more grade 3-4 rash, but less fatigue/asthenia disorder, leukopenia and thrombocytopenia.

CONCLUSIONS

Our analysis suggests that chemotherapy in the second-line setting can prolong PFS in EGFR M- patients, whereas it has no impact on OS. EGFR-TKIs seem superior over chemotherapy as second-line therapy for EGFR M+ patients. Our findings support obtaining information on EGFR mutational status before initiation of second-line treatment.

Diagnostic and therapeutic issues for patients with advanced non‑small cell lung cancer harboring anaplastic lymphoma kinase rearrangement: European vs. US perspective (review)

The recent availability of crizotinib in clinical practice, for the treatment of patients with advanced non-small cell lung cancer (NSCLC) selected by the presence of anaplastic lymphoma kinase (ALK) rearrangement, has relevant implications for both the diagnostic phase and the treatment choices. In the United States, crizotinib was approved by the Food and Drug Administration (FDA) in 2011 for patients with ALK positivity detected by FDA-approved companion diagnostic test. As of January, 2014, the only FDA-approved diagnostic test is Vysis ALK Break-Apart FISH Probe Kit. In Europe, European Medicines Agency (EMA) approved crizotinib for ALK-positive patients in 2012, without specifying the type of test used for determining the positivity. FISH remains the reference technique for ALK determination, but, if fully validated, immunohistochemistry could challenge the current ALK screening practice. Given the robust evidence of activity of crizotinib in ALK-positive patients both pretreated and chemotherapy-naïve, and the favourable tolerability profile of the drug, many oncologists would prefer to administer the drug as early as possible. This is technically feasible in the United States, where crizotinib was approved well before the availability of the results of the randomized phase III trial comparing the drug with standard second-line chemotherapy, and the use of crizotinib in ALK-positive patients is not restricted to a specific line of treatment. On the contrary, in Europe, differently from the FDA decision, crizotinib cannot be used in chemotherapy-naïve patients. In both realities, a deeper knowledge of mechanisms of resistance, the role of repeated biopsies, the treatment strategy for patients experiencing disease progression with crizotinib, the choice of the best chemotherapy regimen are challenging topics for the management of ALK-positive patients in clinical practice.

Surrogate end points and postprogression survival in renal cell carcinoma: an analysis of first-line trials with targeted therapies

Our end point was to determine the correlations between progression-free survival (PFS), postprogression survival (PPS), response rate (RR), and disease control rate (DCR) (RR + stable disease) and overall survival (OS) in first-line trials of renal cell carcinoma (RCC) treated with targeted therapies and to identify a potential surrogate for OS. Data were collected from first-line phase III randomized trials in RCC. Linear regression was undertaken to evaluate the correlations between end points and a potential surrogate end point for OS. Six randomized trials were identified containing a total of 7 treatment arms. The nonparametric Spearman rank correlation coefficients (r(s)) between PFS, PPS, and RR/DCR and OS are 0.869, and 1, 0.96/1 (all P < .0001), respectively. There is a strong relationship between differences (Δ) in DCR and ΔOS (r(s) = 1). The slope of the regression line is 0.3963 ± 0.0019, indicating that a novel drug producing a 10% increase for DCR will yield an estimated absolute 3.9% increase in OS. In first-line trials including novel targeted agents for RCC, PFS is a relatively flawed surrogate end point because of PPS influence. Improvement in DCR is strongly associated with improvement in median OS. In this population, DCR may be an appropriate surrogate for OS.

Reporting trends of outcome measures in phase II and phase III trials conducted in advanced-stage non-small-cell lung cancer

BACKGROUND

The methodology of conducting clinical trials in lung cancer has been challenged by the particular characteristics of new targeted agents. Thus, the choice of correct outcome measures and selection of best study designs are essential. We assessed the trends in reporting of outcome measures in phase II and phase III trials conducted in advanced non-small-cell lung cancer (NSCLC) patients.

METHODS

Data from September 2000 to September 2012 were extracted from the ClinicalTrials.gov database, and a descriptive-comparative analysis was performed to evaluate outcome-measures reporting for the two phases.

RESULTS

We identified 459 phase II and 128 phase III trials that met our inclusion criteria. The frequently reported primary outcomes in phase II trials were progression-free survival (PFS; 32%), response rate (RR; 21.4%), and safety and toxicity (adverse events [AEs]; 14.6%). In contrast, overall survival (OS; 60.9%) and PFS (26.6%) were frequently reported primary outcomes in phase III trials. AEs were reported as a secondary outcome measure in 50.1 and 64.8% of phase II and phase III trials, respectively. Improvement in quality of life was identified as a secondary outcome measure significantly more frequently in phase III than in phase II trials.

CONCLUSIONS

Our study identified recent trends in reports of outcome measures in advanced-stage NSCLC phase II and phase III trials. The outcomes of this study can be valuable for investigators with minimal or some experience in the field of oncology who are conducting clinical research.

Modeling the relationship between progression-free survival and overall survival: the phase II/III trial

The standard phase II trial design has changed dramatically over the past decade. Randomized phase II studies have essentially become the standard phase II design in oncology for a variety of reasons. The use of these designs is motivated by concerns about the use of historical data to determine if a new agent or regimen shows promise of activity. However, randomized phase II designs come with the cost of increased study duration and patient resources. Progression-free survival (PFS) is an important endpoint used in many phase II designs. In many clinical settings, changes in PFS with the introduction of a new treatment may represent true benefit in terms of the gold standard outcome, overall survival (OS). The phase II/III design has been proposed as an approach to shorten the time of discovery of an active regimen. In this article, design considerations for a phase II/III trial are discussed and presented in terms of a model defining the relationship between OS and PFS. The design is also evaluated using 15 phase III trials completed in the Southwest Oncology Group (SWOG) between 1990 and 2005. The model provides a framework to evaluate the validity and properties of using a phase II/III design. In the evaluation of SWOG trials, three of four positive studies would have also proceeded to the final analysis and 10 of 11 negative studies would have stopped at the phase II analysis if a phase II/III design had been used. Through careful consideration and thorough evaluation of design properties, substantial gains could occur using this approach.