Statistical considerations and endpoints for clinical lung cancer studies: Can progression free survival (PFS) substitute overall survival (OS) as a valid endpoint in clinical trials for advanced non-small-cell lung cancer?

In the last decades significant progress has been achieved in the biological understanding of non-small-cell lung cancer (NSCLC) and its tumor heterogeneity has become more evident. The identification of novel tumor targets with different pathways has stimulated the search for anti-tumor agents with a specific target directed mode of action, stipulating the need of testing these agents in clinical trials with an appropriate choice of the study endpoint. Gold standard as an endpoint has been so far overall survival (OS). By definition there are 3 categories of classical endpoints applied generally in clinical lung cancer studies: survival time endpoints, symptom endpoints, and endpoints relying on patients' reporting. Beside classical endpoints like OS which are tending to show the direct clinical effect of treatment, efforts have been taken to substitute these classical endpoints by surrogates. As a surrogate candidate for OS progression-free survival (PFS) should have the inherent considerable advantage, that it can detect subpopulations with longer PFS intervals early. Based on the (sub-) population treated and having in mind the risk-benefit profile of the drug under consideration, PFS can be considered for regulatory decision making. If accompanied by some independent measures like quality of life or treatment toxicity, PFS should be able to cover the clinical benefit achieved by treatment. Selecting PFS as primary endpoint in Phase III trials of advanced NSCLC may be based on a number of questions such as: Does the definition of PFS fit into the setting used by other trials? Are there accepted consensus standards? Are there consistent surveillance intervals? Is validation for each agent group planned? Is the incremental improvement of PFS big enough (≥30%)? And are there some additional measures to confine clinical benefit? OS is still accepted as the gold standard in trials investigating advanced NSCLC. OS is easy to measure and precise but it may be difficult to interpret if treatment action takes place only in a small subinterval of overall survival. PFS with some additional measures has become attractive when it seems advisable to make study results available earlier. Candidates for supporting PFS as "additional measures" may be treatment toxicity and quality of life measures. PFS allows a more precise detection and attribution to effects of the investigational treatment without being compromised by subsequent treatments. Therefore "enriched PFS" can be considered as an alternative primary endpoint replacing OS in studies investigating advanced NSCLC. The endpoint selection process should always be performed carefully considering all true and surrogate endpoint options in respect to the hypotheses to be proven.

Is progression-free survival associated with a better health-related quality of life in patients with lung cancer? Evidence from two randomised trials with afatinib

OBJECTIVE

Progression-free survival (PFS) is frequently used as an efficacy end point in oncology clinical trials. However, there is limited evidence to support a positive association between improvement in PFS and improvement in health-related quality of life (HRQoL). The association between PFS and HRQoL was evaluated in two randomised trials.

MATERIALS AND METHODS

Data from two randomised controlled trials in patients with non-small cell lung cancer (NSCLC; LUX-Lung 1 and LUX-Lung 3) were used to investigate HRQoL in patients to determine whether tumour progression is accompanied by worsening HRQoL. HRQoL was assessed using the cancer-specific European Organization for Research and Treatment of Cancer (EORTC) core questionnaire QLQ-C30, the EuroQol EQ-5D overall utility and EuroQol EQ visual analogue scale. In both studies, progression was evaluated by independent review using RECIST criteria (primary end point) and also by investigator assessment. The relationship between tumour progression and HRQoL was evaluated using analysis of covariance and a longitudinal model.

RESULTS

Compliance with HRQoL questionnaire completion was high. In both studies, patients with progression consistently experienced numerically poorer HRQoL at the time of progression than patients without progression. Differences in mean scores were statistically significant (p<0.05) between patients with and without progression at week 4 in all analyses in LUX-Lung 1 and at multiple time points in LUX-Lung 3. Results from the longitudinal analysis showed that progression (by independent review and investigator assessment) appears to have consistent negative impact on all three HRQoL measures (all p<0.0001).

CONCLUSIONS

Tumour progression in patients with NSCLC was associated with statistically significant worsening in HRQoL. These findings confirm the value of PFS as a patient-relevant end point.

Elevated levels of preoperative circulating CD44⁺ lymphocytes and neutrophils predict poor survival for non-small cell lung cancer patients

BACKGROUND

Certain circulating cells have been shown to predict the clinical outcome of several cancers. The objective of this study was to identify clinical, hematological and immunological predictors of prognosis in non-small cell lung cancer (NSCLC) patients.

METHODS

A retrospective study on a prevalent cohort of 225 NSCLC patients hospitalized at the Zhejiang Province Cancer Hospital (ZPCH) was conducted from August 1, 2006 to April 15, 2008. Circulating lymphocytes were measured by flow cytometry. WBC count and classification in peripheral blood were measured with a Coulter counter. We calculated the proportion of patients surviving after first hospital admission and hazard ratios (HR) using the Cox proportional hazards model.

RESULTS

Elevated levels of preoperative circulating CD44(+) lymphocytes, WBCs and neutrophils indicated low cumulative survival. Clinical stage (HR: 2.292; 95% confidence interval (CI): 1.34-3.91, P=0.002), neutrophils (HR: 1.877; 95% CI: 1.34-2.62, P<0.001) and CD44(+) lymphocytes (HR: 1.018; 95% CI: 1.00-1.03, P=0.002) are independent predictors of survival in NSCLC patients, respectively. Elevated levels of CD44(+) lymphocytes and neutrophils correlated with distant metastasis and prognosis in NSCLC patients with stage III/IV, respectively.

CONCLUSIONS

CD44(+) lymphocytes along with neutrophils could serve as an independent prognostic marker for NSCLC patients.

Interpreting overall survival results when progression-free survival benefits exist in today's oncology landscape: a metastatic renal cell carcinoma case study

Background

The debate surrounding the acceptance of progression-free survival (PFS) as an intermediate endpoint to overall survival (OS) has grown in recent years, due to the challenges in demonstrating an OS benefit within clinical trials today. PFS is generally a good predictor of OS for cases where survival post-progression (SPP) is short, and less so when SPP is long. SPP depends on multiple factors, including residual effect from experimental treatment and effect from crossover or other subsequent therapies, posing unique challenges into the translation of PFS benefit into OS.

Methods

The objective of this analysis was to conduct simulations investigating how increasing SPP impacts PFS translation to OS, utilizing data from the AXIS (axitinib versus sorafenib in advanced metastatic renal cell carcinoma) trial. The underlying assumption was a treatment benefit in PFS (the PFS distribution parameters were chosen to be equal to median PFS in the AXIS trial) but no treatment effect on SPP, implying that PFS improvement is directly reflected in OS improvement.

Results

The probability of a statistically significant difference between arms for OS decreased from 54.7% to 6.1% when median SPP was increased from one to 20 months. The probability of the hazard ratio of OS being ≥0.9 was similarly increased from 24.3% to 72.6%, even though the hazard ratio for PFS was 0.69.

Conclusion

The present study shows that when simulated SPP is added to trial PFS data, the existing PFS benefit is diluted. Knowing that the AXIS treatment arms are well balanced with respect to post-trial treatments, we conclude that the PFS to OS benefit translation is primarily obscured by random variability largely unrelated to the true outcomes. The implications for drug development are not insignificant, as there would be a need to include more patients in studies or utilize a longer follow-up time to overcome the SPP variability issue.

Analysis of endpoints used in marketing authorisations versus value assessments of oncology medicines in Germany

BACKGROUND AND AIMS

In Germany, a mandatory early benefit assessment (EBA) by the Federal Joint Committee (G-BA) is required for reimbursement of new marketing-authorised medicines. Additional benefit is based on patient-relevant endpoints in mortality, morbidity and health-related quality of life (HRQoL). We aimed to compare endpoints and related benefit categories used in marketing authorisation to those considered by G-BA in the field of oncology.

METHODS

We evaluated EBAs in oncology commencing prior to 31 December 2013. Endpoints for the appropriate medicines, derived from European Medicines Agency's (EMA) Summary of Product Characteristics (SPC), manufacturers' value dossiers and G-BA decisions, were grouped into the three benefit categories.

RESULTS

Of 23 oncology medicines evaluated, primary clinical trial endpoints were included in only 12 G-BA value decisions. Mortality endpoints were generally accepted by EMA and G-BA. However, G-BA excluded 80% of (co-)primary morbidity endpoints. Only 5 SPCs reported HRQoL instruments. G-BA accepted applied instruments in 15 medicines, but the manufacturers' analyses only in 5 medicines, of which 2 indicated an additional benefit.

CONCLUSIONS

Mortality endpoints are accepted by EMA and G-BA. EMA accepted well established and clinically relevant morbidity endpoints (e.g. progression-free survival and response rate), which were mostly excluded by G-BA from their value decisions. The applicability of methods used for benefit assessments to HRQoL differs from the mortality and morbidity categories, and requires further clarification.

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.

Surrogate endpoints for overall survival in advanced non-small-cell lung cancer patients with mutations of the epidermal growth factor receptor gene

Subsequent therapies confound the ability to discern the effect of first-line chemotherapy on overall survival (OS). We investigated whether progression-free survival (PFS), post-progression survival (PPS) and tumor response were valid surrogate endpoints for OS following first-line chemotherapy in individual patients with advanced non-small-cell lung cancer (NSCLC) harboring sensitive epidermal growth factor receptor gene mutations. We retrospectively analyzed 35 patients with advanced NSCLC treated with first-line gefitinib. The associations of PFS, PPS and tumor response with OS were analyzed. PPS was found to be strongly correlated with OS, unlike PFS and tumor shrinkage. The factors significantly associated with PPS were performance status (PS) after first-line treatment, best response to second-line treatment and number of regimens used after disease progression. PPS may be a surrogate for OS in this patient population and further therapy after disease progression following first-line chemotherapy may significantly affect OS. However, a larger study is required to validate these results.

Prior EGFR tyrosine-kinase inhibitor therapy did not influence the efficacy of subsequent pemetrexed plus platinum in advanced chemonaïve patients with EGFR-mutant lung adenocarcinoma

Background

Tumor cells before and after epidermal growth-factor receptor (EGFR) tyrosine-kinase inhibitor (TKI) therapy might display different characteristics. The aim of this study was to evaluate the influence of prior EGFR TKI therapy on the efficacy of subsequent pemetrexed plus platinum (PP) in advanced chemonaïve patients with EGFR-mutant lung adenocarcinoma.

Materials and methods

Advanced chemonaïve patients with EGFR-mutant lung adenocarcinoma receiving PP as first-line chemotherapy were enrolled retrospectively in two medical centers of Taiwan. The objective of this study was to compare objective response rate (ORR), disease-control rates (DCR), progression-free survival (PFS), and overall survival (OS) of PP in patients with and without prior EGFR TKI therapy.

Results

In total, 105 patients were analyzed. Sixty-one patients (58.1%) had prior EGFR TKI therapy and used PP as second-line treatment. The other 44 patients (41.9%) received PP as first-line therapy. ORRs of PP in patients with and without prior EGFR TKI therapy were 24.6% and 38.6%, respectively (P=0.138). DCRs of the two groups were 62.3% and 65.9%, respectively (P=0.837). The median PFS (6.1 versus 6.1 months, P=0.639) and OS (34.4 versus 32.3 months, P=0.394) were comparable between the groups with and without prior EGFR TKI therapy. In a subgroup analysis of patients with prior EGFR TKI therapy, there was no significant association between the efficacy of first-line EGFR TKI and the outcome of subsequent PP therapy.

Conclusion

Our results suggested that prior EGFR TKI therapy would not influence the efficacy of subsequent PP therapy in advanced chemonaïve patients with EGFR-mutant lung adenocarcinoma.

Shifting patterns in the interpretation of phase III clinical trial outcomes in advanced non-small-cell lung cancer: the bar is dropping

PURPOSE

Despite multiple trials of new agents in advanced non-small-cell lung cancer (NSCLC), outcomes remain poor. This study explores how the design and interpretation of randomized trials in advanced NSCLC has changed over time.

METHODS

Phase III randomized controlled trials of systemic therapy for advanced NSCLC between 1980 and 2010 were identified, and their primary end point, outcome, statistical significance, and conclusions were recorded.

RESULTS

Of 245 trials identified, 203 were eligible for study inclusion. Although overall survival remains the most common primary end point of phase III trials, more trials from the last decade have used progression-free survival instead (none in 1980 to 1990, 13% in 2001 to 2010; P = .002). The percentage of trials meeting their primary statistical end points remained stable over time; however, the percentage of trials reporting a positive outcome without meeting that end point increased (30% in 1980 to 1990, 53% in 2001 to 2010; P < .001). A trend toward decreasing magnitude of survival gain in positive trials was seen over time (3.9 months in 1980 to 1990, 2.5 months in 2001 to 2010; P = .11), with a concomitant increase in the sample size of clinical trials over the same time period (median: 152 patients in 1980 to 1990, 413 in 2001 to 2010; P < .001). Only studies predating 1990 reported negative results as a result of insufficient magnitude of survival benefit despite statistical significance.

CONCLUSION

A significant shift has occurred over the past three decades in the design and interpretation of phase III trials in advanced NSCLC. The use of survival as the primary measure of benefit is declining, as is the magnitude of benefit deemed clinically relevant.

Factors affecting the association between overall survival and progression-free survival in clinical trials of first-line treatment for patients with advanced non-small cell lung cancer

PURPOSE

New treatment strategies, particularly the introduction of molecular-targeted agents and appropriate patient selection based on histology and/or genotyping, have progressed markedly in recent years, and the overall survival (OS) in advanced non-small cell lung cancer (NSCLC) patients has improved. The aim of the study was to identify factors affecting longer OS than that estimated from progression-free survival (PFS) in first-line treatment for advanced NSCLC.

METHODS

Sixty-five controlled trials for first-line treatment of advanced NSCLC were extracted for the study. Factors influencing higher than predicted OS were examined by logistic regression analysis between the OS-extended group and the OS-association group.

RESULTS

PFS was moderately associated with OS. Twenty arms of 14 trials were categorized as an OS-extended group, in which the ratio of observed OS to estimated OS was found to be over 1.2. On multivariate logistic regression analysis, number of patients lower than 150, average age younger than 63 years, and percentage of squamous carcinoma <30 % were found to significantly affect this relationship.

CONCLUSION

We identified number of patients and well-known prognostic factors including age and histological cancer type as factors influencing longer OS. These factors should be considered for patient eligibility, when PFS is used as a surrogate primary endpoint for OS in randomized clinical trials of first-line treatment for patients with advanced NSCLC.

Patient relevant endpoints in oncology: current issues in the context of early benefit assessment in Germany

The German AMNOG healthcare reform includes a mandatory early-benefit-assessment (EBA) at launch. As per German social code, EBA is based on registration trials and includes evaluation of the patient-relevant effect of the new medicines compared to an appropriate comparator as defined by the Federal Joint Committee (G-BA). Current EBA decisions released have unveiled issues regarding the acceptance of some patient-relevant endpoints as G-BA and IQWiG are grading the endpoints, focusing on overall survival as the preferred endpoint in oncology.A taskforce of experienced German outcomes research, medical, health-technology assessment and biostatistics researchers in industry was appointed. After agreement on core assumptions, a draft position was prepared. Input on iterative versions was solicited from a panel of reviewers from industry and external stakeholders.Distinctive features of registration trials in oncology need to be considered when these studies form basis for EBA, especially in cancer-indications with long post-progression survival; and with several consecutive therapeutic options available post-progression. Ethical committees, caregivers and patients often demand cross-over-designs diluting the treatment-effect on overall survival. Regulatory authorities require evaluation of morbidity-related study endpoints including survival of patients without their disease getting worse (i.e., progression-free survival). Also, progression requires treatment-changes, another strong indicator for its relevance to patients.Based on specific guidelines and clinical trial programs that were developed to be consistent with regulatory guidance, endpoints in oncology are thoroughly evaluated in terms of their patient-relevance. This extensive knowledge and experience should be fully acknowledged during EBA when assessing the patient-relevant benefit of innovative medicines in oncology.

JEL CODES

D61; H51; I18.

First-line management of EGFR-mutated advanced lung adenocarcinoma: recent developments

Gefitinib and erlotinib are small-molecule reversible tyrosine kinase inhibitors (TKIs) of epidermal growth factor receptor (EGFR). Objective responses have been observed frequently in patients with non-small cell lung cancer (NSCLC) harbouring activating EGFR mutations, the most common being deletions in exon 19 and the exon 21 L858R mutation. EGFR mutations are prevalent in female patients, those who have never smoked, those of Asian ethnicity and those who have adenocarcinoma histology. Given the efficacy of EGFR TKIs in advanced NSCLC in the salvage setting, and their favourable toxicity profile compared with conventional chemotherapy, there is considerable interest in evaluating their efficacy in the first-line treatment of advanced NSCLC. To date, there have been several phase II and phase III studies that have examined the efficacy of first-line single-agent EGFR TKIs in unselected, clinically selected or molecularly selected populations. Here we review and compare the differences in these phase III trials. Most phase III trials chose progression-free survival (PFS) rather than overall survival (OS) as their primary endpoint. PFS was prolonged but OS was not. The recent development of novel irreversible EGFR TKIs, such as afatinib and dacomitinib, is also reviewed.

EZH2 inhibition: targeting the crossroad of tumor invasion and angiogenesis

Tumor angiogenesis and metastatic spreading are two highly interconnected phenomena, which contribute to cancer-associated deaths. Thus, the identification of novel strategies to target angiogenesis and metastatic spreading is crucial. Polycomb genes are a set of epigenetic effectors, structured in multimeric repressive complexes. EZH2 is the catalytic subunit of Polycomb repressive complex 2 (PRC2), which methylates histone H3 lysine 27, thereby silencing several tumor-suppressor genes. EZH2 is essential for cancer stem cell self-renewal. Interestingly, cancer stem cells are thought to be the seeds of metastatic spreading and are able to differentiate into tumor-associated endothelial cells. Pre-clinical studies showed that EZH2 is able to silence several anti-metastatic genes (e.g., E-cadherin and tissue inhibitors of metalloproteinases), thereby favoring cell invasion and anchorage-independent growth. In addition, EZH2 seems to play a crucial role in the regulation of tumor angiogenesis. High EZH2 expression predicts poor prognosis, high grade, and high stage in several cancer types. Recently, a small molecule inhibitor of PRC2 (DZNeP) demonstrated promising anti-tumor activity, both in vitro and in vivo. Interestingly, DZNeP was able to inhibit cancer cell invasion and tumor angiogenesis in prostate and brain cancers, respectively. At tumor-inhibiting doses, DZNeP is not harmful for non-transformed cells. In the present manuscript, we review current evidence supporting a role of EZH2 in metastatic spreading and tumor angiogenesis. Using Oncomine datasets, we show that DZNeP targets are specifically silenced in some metastatic cancers, and some of them may inhibit angiogenesis. Based on this evidence, we propose the development of EZH2 inhibitors as anti-angiogenic and anti-metastatic therapy.

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.

Surrogate endpoints for overall survival in chemotherapy and radiotherapy trials in operable and locally advanced lung cancer: a re-analysis of meta-analyses of individual patients' data

Background

The gold standard endpoint in clinical trials of chemotherapy and radiotherapy for lung cancer is overall survival. Although reliable and simple to measure, this endpoint takes years to observe. Surrogate endpoints that would enable earlier assessments of treatment effects would be useful. We assessed the correlations between potential surrogate endpoints and overall survival at individual and trial levels.

Methods

We analysed individual patients' data from 15 071 patients involved in 60 randomised clinical trials that were assessed in six meta-analyses. Two meta-analyses were of adjuvant chemotherapy in non-small-cell lung cancer, three were of sequential or concurrent chemotherapy, and one was of modified radiotherapy in locally advanced lung cancer. We investigated disease-free survival (DFS) or progression-free survival (PFS), defined as the time from randomisation to local or distant relapse or death, and locoregional control, defined as the time to the first local event, as potential surrogate endpoints. At the individual level we calculated the squared correlations between distributions of these three endpoints and overall survival, and at the trial level we calculated the squared correlation between treatment effects for endpoints.

Findings

In trials of adjuvant chemotherapy, correlations between DFS and overall survival were very good at the individual level (ρ²=0·83, 95% CI 0·83–0·83 in trials without radiotherapy, and 0·87, 0·87–0·87 in trials with radiotherapy) and excellent at trial level (R²=0·92, 95% CI 0·88–0·95 in trials without radiotherapy and 0·99, 0·98–1·00 in trials with radiotherapy). In studies of locally advanced disease, correlations between PFS and overall survival were very good at the individual level (ρ² range 0·77–0·85, dependent on the regimen being assessed) and trial level (R² range 0·89–0·97). In studies with data on locoregional control, individual-level correlations were good (ρ²=0·71, 95% CI 0·71–0·71 for concurrent chemotherapy and ρ²=0·61, 0·61–0·61 for modified vs standard radiotherapy) and trial-level correlations very good (R²=0·85, 95% CI 0·77–0·92 for concurrent chemotherapy and R²=0·95, 0·91–0·98 for modified vs standard radiotherapy).

Interpretation

We found a high level of evidence that DFS is a valid surrogate endpoint for overall survival in studies of adjuvant chemotherapy involving patients with non-small-cell lung cancers, and PFS in those of chemotherapy and radiotherapy for patients with locally advanced lung cancers. Extrapolation to targeted agents, however, is not automatically warranted.

Funding

Programme Hospitalier de Recherche Clinique, Ligue Nationale Contre le Cancer, British Medical Research Council, Sanofi-Aventis.

A multicenter phase II study of ganetespib monotherapy in patients with genotypically defined advanced non-small cell lung cancer

PURPOSE

Ganetespib is a novel inhibitor of the heat shock protein 90 (Hsp90), a chaperone protein critical to tumor growth and proliferation. In this phase II study, we evaluated the activity and tolerability of ganetespib in previously treated patients with non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Patients were enrolled into cohort A (mutant EGFR), B (mutant KRAS), or C (no EGFR or KRAS mutations). Patients were treated with 200 mg/m(2) ganetespib by intravenous infusion once weekly for 3 weeks followed by 1 week of rest, until disease progression. The primary endpoint was progression-free survival (PFS) at 16 weeks. Secondary endpoints included objective response (ORR), duration of treatment, tolerability, median PFS, overall survival (OS), and correlative studies.

RESULTS

Ninety-nine patients with a median of 2 prior systemic therapies were enrolled; 98 were assigned to cohort A (n = 15), B (n = 17), or C (n = 66), with PFS rates at 16 weeks of 13.3%, 5.9%, and 19.7%, respectively. Four patients (4%) achieved partial response (PR); all had disease that harbored anaplastic lymphoma kinase (ALK) gene rearrangement, retrospectively detected by FISH (n = 1) or PCR-based assays (n = 3), in crizotinib-naïve patients enrolled to cohort C. Eight patients (8.1%) experienced treatment-related serious adverse events (AE); 2 of these (cardiac arrest and renal failure) resulted in death. The most common AEs were diarrhea, fatigue, nausea, and anorexia.

CONCLUSIONS

Ganetespib monotherapy showed a manageable side effect profile as well as clinical activity in heavily pretreated patients with advanced NSCLCs, particularly in patients with tumors harboring ALK gene rearrangement.

MiR-449c targets c-Myc and inhibits NSCLC cell progression

MicroRNAs (miRNA) play an important role in tumorigenesis, proliferation, and differentiation. Altered miRNA expression in cancer indicates that miRNAs can function as tumor suppressors or oncogenes. MiR-449c downregulation in non-small cell lung cancer (NSCLC) compared with normal lung tissues was investigated in this study. NSCLC cell proliferation and invasion assays indicate that transfection of miR-449c expression plasmid inhibits the proliferation and invasion ability of NCI-H23 and NCI-H838 cells. In addition, miR-449c overexpression could suppress tumor growth in vivo. Morever, c-Myc was identified as a direct target gene of miR-449c. These findings clearly suggest that miR-449c downregulation and c-Myc amplification may be involved in the development of NSCLC.

Prediction of survival benefits from progression-free survival benefits in advanced non-small-cell lung cancer: evidence from a meta-analysis of 2334 patients from 5 randomised trials

OBJECTIVES

To investigate whether progression-free survival (PFS) can be considered a surrogate endpoint for overall survival (OS) in advanced non-small-cell lung cancer (NSCLC).

DESIGN

Meta-analysis of individual patient data from randomised trials.

SETTING

Five randomised controlled trials comparing docetaxel-based chemotherapy with vinorelbine-based chemotherapy for the first-line treatment of NSCLC.

PARTICIPANTS

2331 patients with advanced NSCLC.

PRIMARY AND SECONDARY OUTCOME MEASURES

Surrogacy of PFS for OS was assessed through the association between these endpoints and between the treatment effects on these endpoints. The surrogate threshold effect was the minimum treatment effect on PFS required to predict a non-zero treatment effect on OS.

RESULTS

The median follow-up of patients still alive was 23.4 months. Median OS was 10 months and median PFS was 5.5 months. The treatment effects on PFS and OS were correlated, whether using centres (R&sup2;=0.62, 95% CI 0.52 to 0.72) or prognostic strata (R&sup2;=0.72, 95% CI 0.60 to 0.84) as units of analysis. The surrogate threshold effect was a PFS hazard ratio (HR) of 0.49 using centres or 0.53 using prognostic strata.

CONCLUSIONS

These analyses provide only modest support for considering PFS as an acceptable surrogate for OS in patients with advanced NSCLC. Only treatments that have a major impact on PFS (risk reduction of at least 50%) would be expected to also have a significant effect on OS. Whether these results also apply to targeted therapies is an open question that requires independent evaluation.

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

BACKGROUND

We examined how crossover therapy might affect the association between progression-free survival (PFS) and overall survival (OS) in non-small cell lung cancer (NSCLC).

METHODS

We extracted PFS- and OS-hazard ratios (HRs) in phase III trials of molecular-targeted agents for advanced NSCLC. Their relationship was modeled in a linear function with the coefficient of determination (R-squared) to assess the correlation between PFS and OS.

RESULTS

Thirty-four trials with 35 pairs for the investigational and reference arms were identified (24,158 patients). Overall, there was little correlation between PFS- and OS-HRs (R-squared = 0.14), suggesting PFS-HR could account only for 14% of variation in OS-HR. The median proportion of crossover therapy per trial was 20%. If patients seldom crossed over (none or <1%), the association between PFS- and OS-HRs was strong (R-squared = 0.69). When the proportion of crossover was ≥1%, however, R-squared declined considerably (≥1% to <20% crossover, R-squared = 0.27; ≥20% to <40%, R-squared = 0.06; and ≥40%, R-squared = 0.27).

CONCLUSIONS

A PFS advantage seldom is associated with an OS advantage any longer. Our analysis suggests this is due to a high level of crossover now that an increasing number of active agents are available for NSCLC.

Postprogression survival in patients with advanced non-small-cell lung cancer who receive second-line or third-line chemotherapy

BACKGROUND

The increased availability of active agents has improved overall survival (OS) in patients with advanced non-small-cell lung cancer (NSCLC). We previously showed that postprogression survival (PPS) is highly associated with OS in the first-line setting, but little is known about PPS in the salvage setting. In this study, we analyzed PPS in phase III trials in the second-line or third-line setting.

PATIENTS AND METHODS

A literature search identified 18 trials for previously treated patients with advanced NSCLC. We partitioned OS into progression-free survival (PFS) and PPS and evaluated the association between OS and either PFS or PPS. Correlation analysis to examine whether a treatment benefit for PFS carried over to OS was performed by calculation of incremental gains in OS and PFS at the trial level.

RESULTS

The average median PPS was longer than the average median PFS (5.4 and 2.6 months, respectively). The induction rate for subsequent chemotherapy after second-line or third-line treatment was related to the duration of PPS in linear regression analysis (r(2) = 0.4813). Median OS was highly associated with median PPS but not with PFS (r = 0.94 and 0.51, respectively), and only a weak association between the treatment benefits for PFS and OS was detected (r = 0.29).

CONCLUSIONS

Treatment benefit for OS in patients with advanced NSCLC can be skewed by the effects of subsequent therapies in the second-line or third-line setting. Whether PFS or OS is the more appropriate endpoint for trials in the salvage setting should be considered.

Expression of DNA repair and replication genes in non-small cell lung cancer (NSCLC): a role for thymidylate synthetase (TYMS)

Background

BRCA1 (B), ERCC1 (E), RRM1 (R) and TYMS (T) mRNA expression has been extensively studied with respect to NSCLC patient outcome upon various chemotherapy agents. However, these markers have not been introduced into clinical practice yet. One of the reasons seems to be lack of a standard approach for the classification of the reported high/low mRNA expression. The aim of this study was to determine the prognostic/predictive impact of B, E, R, T in routinely-treated NSCLC patients by taking into account the expression of these genes in the normal lung parenchyma.

Methods

B, E, R, T mRNA expression was examined in 276 NSCLC samples (real-time PCR). The normal range of B, E, R, T transcript levels was first determined in matched tumor – normal pairs and then applied to the entire tumor series. Four main chemotherapy categories were examined: taxanes-without-platinum (Tax); platinum-without-taxanes (Plat); taxanes/platinum doublets (Tax/Plat); and, all-other combinations.

Results

In comparison to remotely located normal lung parenchyma, B, E, R, T mRNA expression was generally increased in matched tumors, as well as in the entire tumor series. Therefore, tumors were classified as expressing normal or aberrant B, E, R, T mRNA. In general, no marker was associated with overall and progression free survival (OS, PFS). Upon multivariate analysis, aberrant intratumoral TYMS predicted for shorter PFS than normal TYMS in 1st line chemo-naïve treated patients (p = 0.012). In the same setting, specific interactions were observed for aberrant TYMS with Plat and Tax/Plat (p = 0.003 and p = 0.006, respectively). Corresponding patients had longer PFS in comparison to those treated with Tax (Plat: HR = 0.234, 95% CI:0.108-0.506, Wald’s p < 0.0001; Tax/Plat: HR = 0.242, 95% CI:0.131-0.447, Wald’s p < 0.0001). Similar results were obtained for PFS in 1st line chemo-naïve and (neo)adjuvant pre-treated patients. Adenocarcinoma, early disease stage, and treatment with Tax/Plat doublets independently predicted for prolonged OS in patients who received only one line of treatment (adjuvant or 1st line).

Conclusion

Classifying intratumoral B, E, R, T mRNA expression in comparison to normal lung may facilitate standardization of these parameters for prospective studies. With this approach, NSCLC patients with aberrant intratumoral TYMS expression will probably fare better with platinum-based treatments.

Issues surrounding clinical trial endpoints in solid malignancies with a focus on metastatic non-small cell lung cancer

Relative to best supportive care alone, cytotoxic chemotherapy has an established role in prolonging overall survival (OS) in patients with or without previous treatment for metastatic non-small cell lung cancer (NSCLC). OS has been the principal endpoint influencing regulatory decisions regarding targeted therapies for metastatic NSCLC, including the vascular endothelial growth factor monoclonal antibody bevacizumab in the frontline setting and the epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib in patients after prior treatment. Progression-free survival (PFS), another common endpoint in oncology clinical trials, has been discussed as a potential surrogate for OS in metastatic NSCLC. A number of phase III clinical trials of investigational targeted agents for treatment of metastatic NSCLC are ongoing, with OS designated as the primary endpoint in some cases and PFS in others. Both endpoints have been developed largely to evaluate outcomes in unselected populations in which a fraction of patients are anticipated to derive significant benefit. New approaches are being considered for the evaluation of targeted agents. Recent high profile trials have been designed to assess PFS using a randomized discontinuation design and disease control rate after 8 weeks of treatment. With a series of recent advances toward increasingly personalized biomarker-directed anticancer therapies, the appropriateness of the traditional regulatory approach has been questioned.

Proposal for a novel methodology to screen and score cost versus survival for anticancer drugs in metastatic disease: could cost weigh in evaluation?

PURPOSE

Rising costs of anticancer drugs prompt concerns about their approval, use, and affordability. A methodology was developed to evaluate cost versus survival for anticancer drugs in metastatic breast cancer and non-small-cell lung cancer (NSCLC).

METHODS

Costs of evaluated drugs were calculated by using average wholesale prices in US dollars. Ratios of cost to day of survival (cost/survival/d) were obtained by dividing costs of the entire treatment by reported median survival gain in days. A crude score of 100% was assigned to a cost/survival/d of less than $25, and 0% to a cost/survival/d of more than $750. A strategy was designed to correct for overall survival (OS) versus progression-free survival (PFS), adverse effects, and quality of life.

RESULTS

In breast cancer, PFS scores of bevacizumab varied between 0% and 60%. In NSCLC, OS scores of bevacizumab improved from 0% to 50%, as a result of histology, lower prices, and extended therapy. Gefitinib and erlotinib PFS scores were 80% and 70%, respectively. Correction for longer survival with erlotinib resulted in similar scores. In maintenance therapy, the OS score for pemetrexed was 70% as compared with 25% for erlotinib. Generic drugs scored 70% to 90%.

CONCLUSION

Cost/survival varied with the number of cycles. In breast cancer, bevacizumab scores failed to justify its use. In NSCLC, 10 cycles of bevacizumab scored 0%. Scores improved with extended treatment and lower prices. Scores for gefitinib and erlotinib would support their approval. Erlotinib was preferred because of longer PFS. Results tended to endorse maintenance pemetrexed but not erlotinib. Generic drugs demonstrated high scores. Cost/survival could weigh in drug evaluation.

Misspecification of Cox regression models with composite endpoints

Researchers routinely adopt composite endpoints in multicenter randomized trials designed to evaluate the effect of experimental interventions in cardiovascular disease, diabetes, and cancer. Despite their widespread use, relatively little attention has been paid to the statistical properties of estimators of treatment effect based on composite endpoints. We consider this here in the context of multivariate models for time to event data in which copula functions link marginal distributions with a proportional hazards structure. We then examine the asymptotic and empirical properties of the estimator of treatment effect arising from a Cox regression model for the time to the first event. We point out that even when the treatment effect is the same for the component events, the limiting value of the estimator based on the composite endpoint is usually inconsistent for this common value. We find that in this context the limiting value is determined by the degree of association between the events, the stochastic ordering of events, and the censoring distribution. Within the framework adopted, marginal methods for the analysis of multivariate failure time data yield consistent estimators of treatment effect and are therefore preferred. We illustrate the methods by application to a recent asthma study. Copyright © 2012 John Wiley & Sons, Ltd.

Patients' preferences for treatment outcomes for advanced non-small cell lung cancer: a conjoint analysis

BACKGROUND

Treatment decisions for advanced non-small cell lung cancer (NSCLC) are complex and require trade-offs between the benefits and risks experienced by patients. We evaluated the benefits that patients judged sufficient to compensate for the risks associated with therapy for NSCLC.

METHODS

Participants with a self-reported diagnosis of NSCLC (n=100) were sampled from an online panel in the United Kingdom. Eligible and consenting participants then completed a self-administered online survey about their disease and their treatment preferences were assessed. This involved respondents choosing among systematically paired profiles that spanned eight attributes: progression-free survival [PFS], symptom severity, rash, diarrhoea, fatigue, nausea and vomiting, fever and infection, and mode of treatment administration (infusion and oral). A choice model was estimated using mixed-logit regression. Estimates of importance for each attribute level and attribute were then calculated and acceptable tradeoffs among attributes were explored.

RESULTS

A total of 89 respondents (73% male) completed all choice tasks appropriately. Increases in PFS together with improvements in symptom severity were judged most important and increased with PFS benefit - 4 months: 5.7; 95% CI: 3.5-7.9; 5 months: 7.1; 95% CI: 4.4-9.9; and 7 months: 10.0; 95% CI: 6.1-13.9. However, improvements in PFS were viewed as most beneficial when disease symptoms were mild and as detrimental when patients had severe symptoms. Fatigue (5.0; 95% CI: 2.7-7.3) was judged to be the most important risk, followed by diarrhoea (2.8; 95% CI: 0.7-4.9), nausea and vomiting (2.1; 95% CI: 0.1-4.1), fever and infection (2.1; 95% CI: 0.2-4.1), and rash (2.0; 95% CI: 0.2-3.9). Oral administration was preferred to infusion (1.8; 95% CI: 0.0-3.6). Patients with mild and moderate symptoms traded PFS for less risks or more convenience if the severe symptoms were not experienced.

CONCLUSION

This study demonstrates the value of conjoint analysis in the study of patient preferences for cancer treatments. In this small sample of patients with NSCLC from the UK, we demonstrate that the value of improvements in PFS is conditional upon the severity of disease symptoms; and that risks are valued differently.

Bevacizumab in non-small-cell lung cancer: a review

Current targeted strategies for cancer focus on the blockade of growth factor receptors and the inhibition of angiogenesis. The VEGF pathway has become an attractive target in multiple malignancies, including lung cancer. Bevacizumab, a monoclonal antibody against VEGF, increased survival in non-small-cell lung cancer (NSCLC) patients when added to standard carboplatin/paclitaxel chemotherapy. The pivotal Phase III study (ECOG 4599) in NSCLC showed longer overall survival: 12.3 versus 10.3 months and a higher median progression-free survival of 6.2 versus 4.5 months when chemotherapy was associated with bevacizumab. Benefits were confirmed in terms of progression-free survival in the European Phase III study (AVAiL). Subsequently, bevacizumab gained US FDA and European Medicines Agengy approval as a first-line therapy for advanced NSCLC. Bevacizumab's safety profile is well established: most adverse events are mild to moderate and can be managed using standard interventions. This article presents an overview of the current data on bevacizumab for NSCLC.

EGFR-mutated oncogene-addicted non-small cell lung cancer: current trends and future prospects

Non-small cell lung cancer (NSCLC) tumours with certain mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase have been termed 'oncogene addicted' to reflect their dependence on EGFR-mediated pro-survival signalling and their high susceptibility to apoptosis induced by EGFR tyrosine kinase inhibitors (EGFR-TKIs, e.g. gefitinib and erlotinib). The most common mutations (L858R and exon 19 deletions) predict an improved clinical response to first-line oral EGFR-TKIs compared with standard platinum-based chemotherapy in patients with advanced NSCLC. Moreover, these mutations are also prognostic of a relatively indolent course of disease, regardless of treatment, as compared with classical NSCLC. Treatment strategies for oncogene-addicted NSCLC are therefore distinct from those for non-oncogene addicted NSCLC, and will depend on the specific genetic mutation present.

Role of survival post-progression in phase III trials of systemic chemotherapy in advanced non-small-cell lung cancer: a systematic review

Background

In advanced non-small-cell lung cancer (NSCLC), with the increasing number of active compounds available in salvage settings, survival after progression to first-line chemotherapy seems to have improved. A literature survey was conducted to examine whether survival post-progression (SPP) has improved over the years and to what degree SPP correlates with overall survival (OS).

Methods and Findings

Median progression-free survival (MPFS) time and median survival time (MST) were extracted in phase III trials of first-line chemotherapy for advanced NSCLC. SPP was pragmatically defined as the time interval of MST minus MPFS. The relationship between MPFS and MST was modeled in a linear function. We used the coefficient of determination (r²) to assess the correlation between them. Seventy trials with 145 chemotherapy arms were identified. Overall, median SPP was 4.7 months, and a steady improvement in SPP was observed over the 20 years (9.414-day increase per year; p<0.001) in parallel to the increase in MST (11.253-day increase per year; p<0.001); MPFS improved little (1.863-day increase per year). Overall, a stronger association was observed between MST and SPP (r² = 0.8917) than MST and MPFS time (r² = 0.2563), suggesting SPP and MPFS could account for 89% and 25% of the variation in MST, respectively. The association between MST and SPP became closer over the years (r² = 0.4428, 0.7242, and 0.9081 in 1988–1994, 1995–2001, and 2002–2007, respectively).

Conclusions

SPP has become more closely associated with OS, potentially because of intensive post-study treatments. Even in advanced NSCLC, a PFS advantage is unlikely to be associated with an OS advantage any longer due to this increasing impact of SPP on OS, and that the prolongation of SPP might limit the original role of OS for assessing true efficacy derived from early-line chemotherapy in future clinical trials.

Randomized controlled trials in the era of molecular oncology: methodology, biomarkers, and end points

BACKGROUND

We previously reported metrics of systemic therapy randomized controlled trials (RCTs) in breast cancer, colorectal cancer (CRC), and non-small-cell lung cancer (NSCLC) published 1975-2004. To evaluate trends in the era of targeted therapies (TT), we have repeated a similar analysis of RCTs published 2005-2009.

METHODS

A search for phase III RCTs of systemic agents published in five major journals 2005-2009 was carried out. Trials were classified as TT if they involved any non-hormonal targeted agent. We extracted data regarding biomarker use. Integral biomarkers were defined as tests used to determine eligibility, stratification, or allocation. Descriptive statistics were used to analyze trends over time.

RESULTS

One hundred and thirty-seven eligible RCTs were evaluated. Compared with 1995-2004, the number (17-27 RCTs/year) and size (median sample size 446-722, P < 0.001) of RCTs increased. The proportion of RCTs evaluating TT increased from 4% (7/167) to 29% (40/137) (P < 0.001). There was an increase in the proportion of trials with financial support from industry [57% (95/167) to 78% (107/137), P = 0.001]. Biomarkers were included in 58% (80/137) of RCTs; integral biomarkers were included in 36% (49/137) of trials. Among the 49 RCTs using integral biomarkers, 40 (82%) used HER2 and/or ER/PR status in studies of breast cancer.

CONCLUSIONS

RCTs published in 2005-2009 are larger, more likely to evaluate TT, and be supported by industry. Biomarkers may be increasingly used, but the most common use relates to traditional use of ER/PR and evolving use of HER2 in breast cancer RCTs.

The value of progression-free survival to patients with advanced-stage cancer

Progression-free survival (PFS) is frequently used as a primary end point in oncology clinical trials. Employing PFS instead of overall survival as the primary outcome has the advantage that trial completion can be quicker with fewer patients required, and it is cheaper. PFS is sensitive to cytostatic as well as cytotoxic mechanisms of therapeutic intervention and directly measures the effect of the investigational treatment. Despite these practical advantages, it is unclear whether or not extending PFS provides discernable clinical benefit. New treatments that increase PFS may not be of sufficient value to patients with advanced-stage cancer unless accompanied by tangible quantity or quality of life advantages. Any symptom relief that patients gain from treatment resulting in tumor shrinkage or stabilization must be balanced against the toxic effects that drug therapy itself creates. Consequently, improved assessment of new treatments using patient-reported outcomes alongside PFS is crucial to enable communication between clinicians and patients and optimal decision-making about therapeutic options.

Estimation of current cumulative incidence of leukaemia-free patients and current leukaemia-free survival in chronic myeloid leukaemia in the era of modern pharmacotherapy

BACKGROUND

The current situation in the treatment of chronic myeloid leukaemia (CML) presents a new challenge for attempts to measure the therapeutic results, as the CML patients can experience multiple leukaemia-free periods during the course of their treatment. Traditional measures of treatment efficacy such as leukaemia-free survival and cumulative incidence are unable to cope with multiple events in time, e.g. disease remissions or progressions, and as such are inappropriate for the efficacy assessment of the recent CML treatment.

METHODS

Standard nonparametric statistical methods are used for estimating two principal characteristics of the current CML treatment: the probability of being alive and leukaemia-free in time after CML therapy initiation, denoted as the current cumulative incidence of leukaemia-free patients; and the probability that a patient is alive and in any leukaemia-free period in time after achieving the first leukaemia-free period on the CML treatment, denoted as the current leukaemia-free survival. The validity of the proposed methods is further documented in the data of the Czech CML patients consecutively recorded between July 2003 and July 2009 as well as in simulated data.

RESULTS

The results have shown a difference between the estimates of the current cumulative incidence function and the common cumulative incidence of leukaemia-free patients, as well as between the estimates of the current leukaemia-free survival and the common leukaemia-free survival. Regarding the currently available follow-up period, both differences have reached the maximum (12.8% and 20.8%, respectively) at 3 years after the start of follow-up, i.e. after the CML therapy initiation in the former case and after the first achievement of the disease remission in the latter.

CONCLUSIONS

Two quantities for the evaluation of the efficacy of current CML therapy that may be estimated with standard nonparametric methods have been proposed in this paper. Both quantities reliably illustrate a patient's disease status in time because they account for the proportion of patients in the second and subsequent disease remissions. Moreover, the model is also applicable in the future, regardless of what the progress in the CML treatment will be and how many treatment options will be available, respectively.

Prognostic influence of metformin as first-line chemotherapy for advanced nonsmall cell lung cancer in patients with type 2 diabetes

BACKGROUND

It has been reported that antidiabetic drugs affect the risk of cancer and the prognosis of patients with diabetes, but few studies have demonstrated the influence of different antidiabetic agents on outcomes after anticancer therapy among patients with cancer. The objective of this study was to evaluate the influence of the antidiabetic drugs metformin and insulin on the prognosis of patients with advanced nonsmall cell lung cancer (NSCLC) plus type 2 diabetes who received first-line chemotherapy.

METHODS

Data on patients with NSCLC who had diabetes from 5 hospitals in China during January 2004 to March 2009 were reviewed retrospectively. Ninety-nine patients were included in the final analysis. The influence of metformin and insulin on chemotherapy response rates and survival in these patients was evaluated.

RESULTS

Chemotherapy with metformin (Group A) produced superior results compared with insulin (Group B) and compared with drugs other than metformin and insulin (Group C) in terms of both progression-free survival (PFS) (8.4 months vs 4.7 months vs 6.4 months, respectively; P = .002) and overall survival (OS) (20.0 months vs 13.1 months vs 13.0 months, respectively; P = .007). Although no significant differences in the response rate (RR) were observed between these 3 groups, when groups B and C (ie, the nonmetformin group) were combined, there was a tendency for better disease control in Group A than that in nonmetformin group. No significant difference in survival was observed between chemotherapy with insulin (Group B) versus other drugs (Group C).

CONCLUSIONS

The current data suggested that metformin may improve chemotherapy outcomes and survival for patients who have NSCLC with diabetes.