Data maturity and follow-up in time-to-event analyses

Balance Index to Determine the Follow-Up Duration of Oncology Trials

Several indices were suggested to determine the follow up duration in oncology trials from either maturity or stability perspective, by maximizing timet $$ t $$ such that the index was either greater or less than a pre-defined cutoff value. However, the selection of cutoff value was subjective and usually no commonly agreed cutoff value existed; sometimes one had to resort to simulations. To solve this problem, a new balance index was proposed, which integrated both data stability and data maturity. Its theoretical properties and relationships with other indices were investigated; then its performance was demonstrated through a case study. The highlights of the index are: (1) easy to calculate; (2) free of cutoff value selection; (3) generally consistent with the other indices while sometimes able to shorten the follow-up duration thus more flexible. For the cases where the new balance index cannot be calculated, a modified balance index was also proposed and discussed. For either single arm trial or randomized clinical trial, the two new balance indices can be implemented to widespread situations such as designing a new trial from scratch, or using aggregated trial information to inform the decision-making in the middle of trial conduct.

Exploration of the regional effects of colchicine in the LoDoCo2 Trial

BACKGROUND

The Low Dose Colchicine 2 (LoDoCo2) trial randomized 5,522 patients with chronic coronary disease to colchicine 0.5mg daily or placebo in a 1:1 ratio and demonstrated the cardiovascular benefits of colchicine. In the trial, which was conducted in Australia and The Netherlands, a prespecified subgroup analysis suggested a difference in magnitude of treatment effect of colchicine by region (Australia: HR 0.51; 95% CI 0.39-0.67 vs The Netherlands: HR 0.92; 95% CI 0.71-1.20). The aim of this study was to explore possible explanations for the apparent difference in magnitude of treatment effect of colchicine by region in the LoDoCo2 trial.

METHODS

The analysis explored potential determinants of variations in the magnitude of effectiveness of colchicine treatment across the regions. This included investigating differences in investigational product, clinical characteristics, concurrent medical therapies and the duration of follow-up using a range of statistical techniques, including sub-group, landmark and effect modification analyses.

RESULTS

No differences were found in the colchicine product used in each region. Despite minor differences observed in baseline clinical characteristics and concomitant therapies, the effect modifier analyses demonstrated that these factors did not explain the difference in magnitude of treatment effect of colchicine by region. Randomization in Australia began more than two years before The Netherlands, with shorter duration of follow-up in The Netherlands compared to Australia. In a landmark analysis, over the period when more than 90% of patients in each region had been followed, the effects of colchicine were similar (Australia hazard ratio [HR] 0.58 95% CI 0.34-0.97 vs The Netherlands HR 0.67 95% CI 0.47-0.96).

CONCLUSIONS

After examining several plausible explanations for the observed differences in the magnitude of treatment effect of colchicine between regions in the LoDoCo2 trial could be due to the differences in duration of follow-up but a substantial portion of the differences remain unexplained.

CLINICAL TRIAL REGISTRATION

https://www.anzctr.org.au/ACTRN12614000093684.

Dendritic Cell-Based Immunotherapy in Patients With Resected Pancreatic Cancer

PURPOSE

Immunotherapies have shown limited responses in patients with advanced pancreatic cancer. Recently, we reported that dendritic cell (DC)-based immunotherapy induced T-cell responses against pancreatic cancer antigens. The primary objective of this study was to determine the efficacy of DC-based immunotherapy to prevent recurrence of disease.

METHODS

This was a single-center, open-label, single-arm, combined phase I/II trial. The primary end point was the 2-year recurrence-free survival (RFS) rate. A 2-year RFS rate of ≥60% was defined as a clinically meaningful improvement. We included patients with pancreatic cancer after resection and completion of standard-of-care (SOC) treatment without recurrent disease on cross-sectional imaging. Patients were treated with autologous DCs pulsed with an allogeneic mesothelioma tumor cell lysate, comprising antigens also expressed in pancreatic ductal adenocarcinoma.

RESULTS

Thirty-eight patients were included in the analysis of the primary end point (47% male, 53% female). The median age was 62 years (IQR, 55-68). Twenty-eight patients (74%) received five DC vaccinations and completed the study protocol. Three patients (8%) received four vaccinations, and seven patients (16%) received three vaccinations. After a median follow-up of 25.5 months, 26 patients (68%) had not developed recurrence of disease. The estimated 2-year RFS was 64%. Vaccination led to the enrichment of circulating activated CD4+ T cells and the detection of treatment-induced immune responses in vitro. T-cell receptor-sequencing analyses of a resected solitary lung metastasis showed influx of vaccine-specific T cells.

CONCLUSION

This study reached its primary end point of a 2-year RFS rate of ≥60% following pancreatectomy after SOC treatment and adjuvant DC-based immunotherapy in patients with pancreatic cancer. These results warrant a future randomized trial.

Randomized phase 2 dose comparison LITESPARK-013 study of belzutifan in patients with advanced clear cell renal cell carcinoma

BACKGROUND

Belzutifan is a first-in-class HIF-2α inhibitor approved at a dose of 120 mg once daily for certain adults with VHL disease and adults with advanced renal cell carcinoma (RCC) following therapy with a programmed death receptor (or ligand)-1 (PD-[L]1) inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor. However, whether belzutifan dose could be optimized is unclear.

PATIENTS AND METHODS

The phase 2 LITESPARK-013 study (NCT04489771) enrolled patients with advanced clear cell RCC whose disease progressed after 1-3 prior systemic therapies, including an anti-PD-(L)1 regimen. Patients were randomly assigned 1:1 to receive belzutifan 120 mg or 200 mg once daily. The primary endpoint was objective response rate (ORR) per RECIST v1.1. Secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Overall, 154 patients were enrolled (120 mg: n = 76; 200 mg: n = 78). Median follow-up was 20.1 months (range 14.8-28.4). ORR was 23.7% vs 23.1% for the 120 mg and 200 mg groups, respectively (P = 0.5312; -0.5% [95% CI, -14.0 to 12.9]. Median DOR was not reached for the 120 mg arm and was 16.1 months (2.1+ to 23.5+) for the 200 mg arm. No between-group differences were observed for PFS (HR 0.94 [95% CI 0.63-1.40]) or OS (medians not reached; HR 1.11 [95% CI, 0.65-1.90]). Grade 3 or 4 treatment-related adverse events were observed in 35 patients (46.1%) in the 120 mg group and 36 patients (46.2%) in the 200 mg group.

CONCLUSION

The efficacy of belzutifan was similar between the 120-mg dose and the 200-mg dose for previously treated clear cell RCC. Safety at both doses was consistent with the known safety profile of belzutifan. These results further support 120 mg once daily as the preferred dose for belzutifan.

Avoiding Delays in Reporting Time-to-Event Randomized Trials: Calendar Backstops and Other Approaches

New oncology therapies that extend patients' lives beyond initial expectations and improving later-line treatments can lead to complications in clinical trial design and conduct. In particular, for trials with event-based analyses, the time to observe all the protocol-specified events can exceed the finite follow-up of a clinical trial or can lead to much delayed release of outcome data. With the advent of multiple classes of oncology therapies leading to much longer survival than in the past, this issue in clinical trial design and conduct has become increasingly important in recent years. We propose a straightforward prespecified backstop rule for trials with a time-to-event analysis and evaluate the impact of the rule with both simulated and real-world trial data. We then provide recommendations for implementing the rule across a range of oncology clinical trial settings.

Budget impact analysis of introducing fruquintinib for metastatic colorectal cancer previously treated with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy and biologics in the United States from the payer perspective

AIMS

Fruquintinib is a selective small molecule tyrosine kinase inhibitor of vascular endothelial growth factor receptor (VEGFR)-1, -2, and -3 recently approved in the United States (US) for the treatment of adult patients with metastatic colorectal cancer (CRC) who have previously been treated with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy, an anti-VEGF biological therapy, and if RAS wild-type and medically appropriate, anti-epidermal growth factor receptor therapy. This study aimed to estimate the 5-year budget impact of fruquintinib from a US payer perspective (commercial and Medicare).

MATERIALS AND METHODS

A budget impact model was developed to compare two scenarios: a reference scenario in which patients received regorafenib, trifluridine/tipiracil, or trifluridine/tipiracil with bevacizumab and an alternative scenario in which patients received reference scenario treatments or fruquintinib. Market shares were evenly divided across available options. A 5-year time horizon and a hypothetical health plan of 1 million members was assumed. The model included epidemiological inputs to estimate the eligible population; clinical inputs for treatment duration, progression-free survival, overall survival, and adverse event (AE) frequency; and cost inputs for treatment, AEs, disease management, subsequent therapy, and terminal care costs. Budget impact was reported as total, per member per year (PMPY), and per member per month (PMPM).

RESULTS

The model estimated an eligible population of 194 patients (39 per year) over 5 years. In the base case, the estimated 5-year budget impact of fruquintinib was $4,077,073 ($0.82 PMPY and 0.07 PMPM) for a commercial health plan. During the first year, the estimated budget impact was $627,570 ($0.63 PMPY and 0.05 PMPM). Results were robust across sensitivity analyses. PMPM costs from the Medicare perspective were greater than the base-case (commercial) ($0.17 vs. $0.07) due to higher incidence of CRC in that population.

CONCLUSIONS

Fruquintinib is associated with a low budget impact for payers based on proposed thresholds in the US.

Effect of metastatic calcification on complication rate and survival in 74 renal transplant cats (1998-2020)

OBJECTIVE

To report the incidence of metastatic calcification in cats with renal failure presenting for renal transplantation, and to determine if metastatic calcification detected prior to renal transplantation is associated with complication rates and patient survival.

STUDY DESIGN

Retrospective case series.

SAMPLE POPULATION

Seventy-four cats.

METHODS

In imaging studies, 178 feline renal transplant recipients from 1998 to 2020 were evaluated for metastatic calcification. Demographic, clinicopathological data, intraoperative complications, postoperative complications, need for hemodialysis, and survival times were recorded. Exclusion criteria were cats lacking imaging reports and cats with gastric, renal, or tracheal/bronchial calcification alone. Univariable and multivariable analyses were performed to determine variables that were independently associated with survival. Kaplan-Meier analysis was used to generate survival plots and estimate median survival times with a 95% confidence interval (CI).

RESULTS

Seventy four of 178 cats met the inclusion criteria. Fifteen of 74 (20.3%) cats had metastatic calcification prior to renal transplantation. Twelve of 74 (16.2%) cats developed calcification following transplantation, and 47 of 74 (63.5%) cats had no calcification during the study period. Median follow-up time was 472 days, with a range of 0-1825 days. Cats with pretransplant calcification had shorter median survival times (147 days) than cats without calcification (646 days) (p = .0013). Metastatic calcification pretransplant was associated with an increased risk of death by 240% (95% CI, 1.22-4.71).

CONCLUSION

Metastatic calcification in renal transplant cats is a negative prognostic indicator and is associated with decreased survival times.

CLINICAL SIGNIFICANCE

These findings may help guide therapeutic recommendations and owner expectations in cats undergoing renal transplantation.

Survival following vertebral compression fractures in population over 65 years old

BACKGROUND

Lower mortality has been demonstrated when vertebral compression fractures (VCFs) are treated surgically (vertebral augmentation) vs. conservatively.

AIMS

To analyze the overall survival in patients over 65 who suffer a VCF, to review the principal causes of death, and to detect which factors are associated with a greater risk of mortality.

METHODS

Patients over 65 years old diagnosed with acute, non-pathologic thoracic or lumbar VCF, treated consecutively from January 2017 to December 2020, were retrospectively selected. Those patients with follow-ups under 2 years or who required arthrodesis were excluded. Overall survival was estimated by the Kaplan-Meier method. Differences in survival were tested through the log-rank test. Multivariable Cox regression was used to assess the association of covariates and time to death.

RESULTS

A total of 492 cases were included. Overall mortality was 36.2%. Survival rate at 1-, 12-, 24-, 48-, and 60-month follow-up was 97.4%, 86.6%, 78.0%, 64.4%, and 59.4%, respectively. Infection was the leading cause of death. The independent factors associated with a higher mortality risk were age, male, oncologic history, non-traumatic mechanism, and comorbidity during hospitalization. No statistical difference was found when comparing the two survival curves by treatment (vertebral augmentation vs. conservative) over time.

CONCLUSION

Overall mortality rate was 36.2% after a median follow-up of 50.5 months (95% CI 48.2; 54.2). Age, male sex, history of oncological disease, non-traumatic mechanism of the fracture, and any comorbidity during hospitalization were identified as variables independently associated with a higher risk of mortality following a VCF in the elderly.

A Systematic Review of Methods to Incorporate External Evidence into Trial-Based Survival Extrapolations for Health Technology Assessment

BACKGROUND

External evidence is commonly used to inform survival modeling for health technology assessment (HTA). While there are a range of methodological approaches that have been proposed, it is unclear which methods could be used and how they compare.

PURPOSE

This review aims to identify, describe, and categorize established methods to incorporate external evidence into survival extrapolation for HTA.

DATA SOURCES

Embase, MEDLINE, EconLit, and Web of Science databases were searched to identify published methodological studies, supplemented by hand searching and citation tracking.

STUDY SELECTION

Eligible studies were required to present a novel extrapolation approach incorporating external evidence (i.e., data or information) within survival model estimation.

DATA EXTRACTION

Studies were classified according to how the external evidence was integrated as a part of model fitting. Information was extracted concerning the model-fitting process, key requirements, assumptions, software, application contexts, and presentation of comparisons with, or validation against, other methods.

DATA SYNTHESIS

Across 18 methods identified from 22 studies, themes included use of informative prior(s) (n = 5), piecewise (n = 7), and general population adjustment (n = 9), plus a variety of "other" (n = 8) approaches. Most methods were applied in cancer populations (n = 13). No studies compared or validated their method against another method that also incorporated external evidence.

LIMITATIONS

As only studies with a specific methodological objective were included, methods proposed as part of another study type (e.g., an economic evaluation) were excluded from this review.

CONCLUSIONS

Several methods were identified in this review, with common themes based on typical data sources and analytical approaches. Of note, no evidence was found comparing the identified methods to one another, and so an assessment of different methods would be a useful area for further research.HighlightsThis review aims to identify methods that have been used to incorporate external evidence into survival extrapolations, focusing on those that may be used to inform health technology assessment.We found a range of different approaches, including piecewise methods, Bayesian methods using informative priors, and general population adjustment methods, as well as a variety of "other" approaches.No studies attempted to compare the performance of alternative methods for incorporating external evidence with respect to the accuracy of survival predictions. Further research investigating this would be valuable.

Quantification of follow-up time in oncology clinical trials with a time-to-event endpoint: Asking the right questions

For the analysis of a time-to-event endpoint in a single-arm or randomized clinical trial it is generally perceived that interpretation of a given estimate of the survival function, or the comparison between two groups, hinges on some quantification of the amount of follow-up. Typically, a median of some loosely defined quantity is reported. However, whatever median is reported, is typically not answering the question(s) trialists actually have in terms of follow-up quantification. In this paper, inspired by the estimand framework, we formulate a comprehensive list of relevant scientific questions that trialists have when reporting time-to-event data. We illustrate how these questions should be answered, and that reference to an unclearly defined follow-up quantity is not needed at all. In drug development, key decisions are made based on randomized controlled trials, and we therefore also discuss relevant scientific questions not only when looking at a time-to-event endpoint in one group, but also for comparisons. We find that different thinking about some of the relevant scientific questions around follow-up is required depending on whether a proportional hazards assumption can be made or other patterns of survival functions are anticipated, for example, delayed separation, crossing survival functions, or the potential for cure. We conclude the paper with practical recommendations.

Concurrent chemoradiotherapy followed by adjuvant cisplatin-gemcitabine versus cisplatin-fluorouracil chemotherapy for N2-3 nasopharyngeal carcinoma: a multicentre, open-label, randomised, controlled, phase 3 trial

BACKGROUND

Patients with N2-3 nasopharyngeal carcinoma have a high risk of treatment being unsuccessful despite the current practice of using a concurrent adjuvant cisplatin-fluorouracil regimen. We aimed to compare the efficacy and safety of concurrent adjuvant cisplatin-gemcitabine with cisplatin-fluorouracil in N2-3 nasopharyngeal carcinoma.

METHODS

We conducted an open-label, randomised, controlled, phase 3 trial at four cancer centres in China. Eligible patients were aged 18-65 years with untreated, non-keratinising, stage T1-4 N2-3 M0 nasopharyngeal carcinoma, an Eastern Cooperative Oncology Group performance status score of 0-1, and adequate bone marrow, liver, and renal function. Eligible patients were randomly assigned (1:1) to receive concurrent cisplatin (100 mg/m2 intravenously) on days 1, 22, and 43 of intensity-modulated radiotherapy followed by either gemcitabine (1 g/m2 intravenously on days 1 and 8) and cisplatin (80 mg/m2 intravenously for 4 h on day 1) once every 3 weeks or fluorouracil (4 g/m2 in continuous intravenous infusion for 96 h) and cisplatin (80 mg/m2 intravenously for 4 h on day 1) once every 4 weeks, for three cycles. Randomisation was done using a computer-generated random number code with a block size of six, stratified by treatment centre and nodal category. The primary endpoint was 3-year progression-free survival in the intention-to-treat population (ie, all patients randomly assigned to treatment). Safety was assessed in all participants who received at least one dose of chemoradiotherapy. This study was registered at ClinicalTrials.gov, NCT03321539, and patients are currently under follow-up.

FINDINGS

From Oct 30, 2017, to July 9, 2020, 240 patients (median age 44 years [IQR 36-52]; 175 [73%] male and 65 [27%] female) were randomly assigned to the cisplatin-fluorouracil group (n=120) or cisplatin-gemcitabine group (n=120). As of data cutoff (Dec 25, 2022), median follow-up was 40 months (IQR 32-48). 3-year progression-free survival was 83·9% (95% CI 75·9-89·4; 19 disease progressions and 11 deaths) in the cisplatin-gemcitabine group and 71·5% (62·5-78·7; 34 disease progressions and seven deaths) in the cisplatin-fluorouracil group (stratified hazard ratio 0·54 [95% CI 0·32-0·93]; log rank p=0·023). The most common grade 3 or worse adverse events that occurred during treatment were leukopenia (61 [52%] of 117 in the cisplatin-gemcitabine group vs 34 [29%] of 116 in the cisplatin-fluorouracil group; p=0·00039), neutropenia (37 [32%] vs 19 [16%]; p=0·010), and mucositis (27 [23%] vs 32 [28%]; p=0·43). The most common grade 3 or worse late adverse event (occurring from 3 months after completion of radiotherapy) was auditory or hearing loss (six [5%] vs ten [9%]). One (1%) patient in the cisplatin-gemcitabine group died due to treatment-related complications (septic shock caused by neutropenic infection). No patients in the cisplatin-fluorouracil group had treatment-related deaths.

INTERPRETATION

Our findings suggest that concurrent adjuvant cisplatin-gemcitabine could be used as an adjuvant therapy in the treatment of patients with N2-3 nasopharyngeal carcinoma, although long-term follow-up is required to confirm the optimal therapeutic ratio.

FUNDING

National Key Research and Development Program of China, National Natural Science Foundation of China, Guangdong Major Project of Basic and Applied Basic Research, Sci-Tech Project Foundation of Guangzhou City, Sun Yat-sen University Clinical Research 5010 Program, Innovative Research Team of High-level Local Universities in Shanghai, Natural Science Foundation of Guangdong Province for Distinguished Young Scholar, Natural Science Foundation of Guangdong Province, Postdoctoral Innovative Talent Support Program, Pearl River S&T Nova Program of Guangzhou, Planned Science and Technology Project of Guangdong Province, Key Youth Teacher Cultivating Program of Sun Yat-sen University, the Rural Science and Technology Commissioner Program of Guangdong Province, and Fundamental Research Funds for the Central Universities.

Economic evaluation of five first-line PD-(L)1 inhibitors for treating non-squamous non-small cell lung cancer in China: A cost-effectiveness analysis based on network meta-analysis

Background and objective: Non-small cell lung cancer (NSCLC) is one of the most malignant cancer types that causes substantial economic burden in China. This study aimed to evaluate the cost-effectiveness of five first-line anti-PD-(L)1 treatments, including sintilimab, camrelizumab, atezolizumab, pembrolizumab and sugemalimab with each combined with chemotherapy, for treating advanced non-squamous NSCLC (nsq-NSCLC) from Chinese healthcare system perspective. Methods: Clinical data were obtained from the following clinical trials, namely, ORIENT-11, CameL, IMpower132, KEYNOTE-189 and GEMSTONE-302. A network meta-analysis was performed based on fractional polynomial models. We constructed a partitioned survival model with a three-week cycle length and a lifetime horizon to derive the incremental cost-effectiveness ratio (ICER). We performed one-way sensitivity analysis and probablistic sensitivity analysis to test the robustness. Additionally, two scenario analyses were undertaken to investigate the impact of Patient Assistant Program on the economic conclusion and to explore potential uncertainty associated with population representativeness of the global trial. Results: Compared with camrelizumab + chemotherapy, sugemalimab + chemotherapy and atezolizumab + chemotherapy were dominated, and the ICERs generated from sintilimab + chemotherapy and pembrolizumab + chemotherapy were $15,280.83/QALY and $159,784.76/QALY, respectively. Deterministic sensitivity analysis showed that uncertainty around ICERs was mainly driven by HR related parameters derived from NMA and drug price. The probablistic sensitivity analysis suggested that camrelizumab treatment was cost-effective at a willingness-to-pay threshold of 1-time GDP per capita. When the threshold was set as 3-time GDP per capita, sintilimab strategy demonstrated the excellent cost-effective advantage. Sensitivity analysis proved the reliability of base-case results. Results from two scenario analyses indicated that the primary finding was robust. Conclusion: In current context of Chinese healthcare system, sintilimab + chemotherapy appeared to be cost-effective for the treatment of nsq-NSCLC compared with sugemalimab, camrelizumab, pembrolizumab as well as atezolizumab combined with chemotherapy.

Agovi A, Anikpo IO, Fasanmi EO, Thompson EL, Reeves JM, Thompson CT, Johnson ME, Golub V, Ojha RP. Effect of 2018 American College of Cardiology/American Heart Association Guideline Change on Statin Prescription for People Living with HIV

The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines were updated in 2018 to explicitly recommend statin use for primary cardiovascular disease prevention among people living with HIV (PLWH), but little is known about the effect of this guideline change. We aimed to assess the effect of the 2018 ACC/AHA guideline change on statin prescription among PLWH. We used data from an institutional HIV registry to identify PLWH aged 40-75 years, engaged in HIV care between June 2016 and May 2021, had a LDL cholesterol between 70 and 189 mg/dl, 10-year atherosclerotic cardiovascular disease (ASCVD) risk score ≥7.5%, no prior statin prescription, and no history of diabetes or ASCVD. Our outcome of interest was a new statin prescription within 12 months of eligibility. We estimated standardized risk difference (RD) with 95% confidence limits (CL) by comparing prescription probabilities before and after guideline change. Our study population comprised 251 PLWH (171 before, 80 after the guideline change), of whom 57% were aged <55 years, 82% were male, and 45% were non-Hispanic black. The standardized 12-month statin prescription risk was 43% (95% CL: 31%, 60%) after the guideline change and 19% (95% CL: 13%, 26%) before the guideline change (RD = 25%, 95% CL: 9.1%, 40%). Our results suggest that the 2018 ACC/AHA guideline change increased statin prescription among PLWH, but a sizable proportion of eligible PLWH were not prescribed statin. Future studies are needed to identify strategies to enhance implementation of statin prescription guidelines among PLWH.

Projecting overall survival in health-economic models: uncertainty and maturity of data

OBJECTIVE

As lifetime horizons are considered for economic evaluations, the Kaplan-Meier (KM) estimate is used to extrapolate survival in cases of immature overall survival (OS) data. This study estimated the error induced by the choice of distribution when extrapolating different levels of OS maturity.

METHODS

Fifteen phase 3 trials reporting KM estimates of OS where at least 70% maturity (i.e. 70% of the population had died during follow-up) were included and compared to artificially created truncated data (30 and 50% maturity). Individual patient-data were reproduced using the Guyot algorithm based on digitized KM curves. Parametric survival distributions were fit for each arm in each study, for each maturity level, using the same time horizon (equal to the maximum follow-up). For each KM curve, the best distribution was chosen based on visual inspection, Akaike/Bayesian information criteria, and external validity. Outcomes were measured as life expectancy in months (LM) and life months gained (LMG).

RESULTS

The Weibull (33%), log-logistic (32%) and log-normal (27%) were most often selected as the best fitting distribution. Compared to LM at full maturity, LM was overestimated in 23 and 40% of cases, at 30 and 50% maturity, respectively. Mean absolute error was 2.12months at 30% maturity, and decreased to 0.88months at 50% maturity. When comparing to mature data, the mean percentage of error in LMG was 126.4 and 62.4% at 30 and 50% maturity, respectively.

CONCLUSION

The extent of OS maturity increases the risk of error when projecting long-term life expectancy for economic models. Even marginal gains in OS maturity result in more accurate estimations and should be considered when developing models.

A Guide to Selecting Flexible Survival Models to Inform Economic Evaluations of Cancer Immunotherapies

OBJECTIVES

Parametric models are routinely used to estimate the benefit of cancer drugs beyond trial follow-up. The advent of immune checkpoint inhibitors has challenged this paradigm, and emerging evidence suggests that more flexible survival models, which can better capture the shapes of complex hazard functions, might be needed for these interventions. Nevertheless, there is a need for an algorithm to help analysts decide whether flexible models are required and, if so, which should be chosen for testing. This position article has been produced to bridge this gap.

METHODS

A virtual advisory board comprising 7 international experts with in-depth knowledge of survival analysis and health technology assessment was held in summer 2021. The experts discussed 24 questions across 6 topics: the current survival model selection procedure, data maturity, heterogeneity of treatment effect, cure and mortality, external evidence, and additions to existing guidelines. Their responses culminated in an algorithm to inform selection of flexible survival models.

RESULTS

The algorithm consists of 8 steps and 4 questions. Key elements include the systematic identification of relevant external data, using clinical expert input at multiple points in the selection process, considering the future and the observed hazard functions, assessing the potential for long-term survivorship, and presenting results from all plausible models.

CONCLUSIONS

This algorithm provides a systematic, evidence-based approach to justify the selection of survival extrapolation models for cancer immunotherapies. If followed, it should reduce the risk of selecting inappropriate models, partially addressing a key area of uncertainty in the economic evaluation of these agents.

c4c: Paediatric pharmacovigilance: Methodological considerations in research and development of medicines for children - A c4c expert group white paper

Children frequently respond differently to therapies compared to adults. Differences also exist between paediatric age groups for pharmacokinetics and pharmacodynamics in both efficacy and safety. Paediatric pharmacovigilance requires an understanding of the unique aspects of children with regard to, for example, drug response, growth and development, clinical presentation of adverse drug reactions (ADRs), how they can be detected and population-specific factors (e.g., more frequent use of off-label/unlicensed drugs). In recognition of these challenges, a group of experts has been formed in the context of the conect4children (c4c) project to support paediatric drug development. This expert group collaborated to develop methodological considerations for paediatric drug safety and pharmacovigilance throughout the life-cycle of medicinal products which are described in this article. These considerations include practical points to consider for the development of the paediatric section of the risk management plan (RMP), safety in paediatric protocol development, safety data collection and analysis. Furthermore, they describe the specific details of post-marketing pharmacovigilance in children using, for example, spontaneous reports, electronic health care records, registries and record-linkage, as well as the use of paediatric pharmacoepidemiology studies for risk characterisation. Next the details of the assessment of benefit-risk and challenges related to medicinal product formulation in the context of a Paediatric Investigation Plan (PIP) are presented. Finally, practical issues in paediatric signal detection and evaluation are included. This paper provides practical points to consider for paediatric pharmacovigilance throughout the life-cycle of medicinal products for RMPs, protocol development, safety data collection and analysis and PIPs.

Neoadjuvant Chemoradiotherapy and Surgery for Esophageal Squamous Cell Carcinoma Versus Definitive Chemoradiotherapy With Salvage Surgery as Needed: The Study Protocol for the Randomized Controlled NEEDS Trial

Background

The globally dominant treatment with curative intent for locally advanced esophageal squamous cell carcinoma (ESCC) is neoadjuvant chemoradiotherapy (nCRT) with subsequent esophagectomy. This multimodal treatment leads to around 60% overall 5-year survival, yet with impaired post-surgical quality of life. Observational studies indicate that curatively intended chemoradiotherapy, so-called definitive chemoradiotherapy (dCRT) followed by surveillance of the primary tumor site and regional lymph node stations and surgery only when needed to ensure local tumor control, may lead to similar survival as nCRT with surgery, but with considerably less impairment of quality of life. This trial aims to demonstrate that dCRT, with selectively performed salvage esophagectomy only when needed to achieve locoregional tumor control, is non-inferior regarding overall survival, and superior regarding health-related quality of life (HRQOL), compared to nCRT followed by mandatory surgery, in patients with operable, locally advanced ESCC.

Methods

This is a pragmatic open-label, randomized controlled phase III, multicenter trial with non-inferiority design with regard to the primary endpoint overall survival and a superiority hypothesis for the experimental intervention dCRT with regard to the main secondary endpoint global HRQOL one year after randomization. The control intervention is nCRT followed by preplanned surgery and the experimental intervention is dCRT followed by surveillance and salvage esophagectomy only when needed to secure local tumor control. A target sample size of 1200 randomized patients is planned in order to reach 462 events (deaths) during follow-up.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier: NCT04460352.

Artificial Intelligence-Based Prognostic Model for Urologic Cancers: A SEER-Based Study

Simple Summary

We describe a risk profile reconstruction model for cancer-specific survival estimation for continuous time points after urologic cancer diagnosis. We used artificial intelligence (AI)-based algorithms, a national cancer registry data, and accessible clinical parameters for the risk-profile reconstruction. We derived a risk stratification model and estimated the minimum follow-up duration and the likelihood for risk stability in prostate, kidney, and testicular cancers. The estimated follow-up duration was in alignment with recognized clinical guidelines for these cancers. Moreover, the estimated follow-up duration was differed by the cancer origin and the disease dissemination status. Overall, the reconstruction of the population’s risk profile for the cancer-specific prognostic score estimation is feasible using AI and has potential application in clinical settings to improve risk stratification and surveillance management.

Abstract

Background: Prognostication is essential to determine the risk profile of patients with urologic cancers. Methods: We utilized the SEER national cancer registry database with approximately 2 million patients diagnosed with urologic cancers (penile, testicular, prostate, bladder, ureter, and kidney). The cohort was randomly divided into the development set (90%) and the out-held test set (10%). Modeling algorithms and clinically relevant parameters were utilized for cancer-specific mortality prognosis. The model fitness for the survival estimation was assessed using the differences between the predicted and observed Kaplan–Meier estimates on the out-held test set. The overall concordance index (c-index) score estimated the discriminative accuracy of the survival model on the test set. A simulation study assessed the estimated minimum follow-up duration and time points with the risk stability. Results: We achieved a well-calibrated prognostic model with an overall c-index score of 0.800 (95% CI: 0.795–0.805) on the representative out-held test set. The simulation study revealed that the suggestions for the follow-up duration covered the minimum duration and differed by the tumor dissemination stages and affected organs. Time points with a high likelihood for risk stability were identifiable. Conclusions: A personalized temporal survival estimation is feasible using artificial intelligence and has potential application in clinical settings, including surveillance management.

Overall Survival and Biomarker Analysis of Neoadjuvant Nivolumab Plus Chemotherapy in Operable Stage IIIA Non-Small-Cell Lung Cancer (NADIM phase II trial)

Neoadjuvant chemotherapy plus nivolumab has been shown to be effective in resectable non–small-cell lung cancer (NSCLC) in the NADIM trial (ClinicalTrials.gov identifier: NCT03081689). The 3-year overall survival (OS) and circulating tumor DNA (ctDNA) analysis have not been reported.

Assessing the Impact of Primary Tumour Location on Survival After Resection of Colorectal Liver Metastases: A Propensity Weighted Retrospective Cohort Study

BACKGROUND

Right-sided colonic tumours appear to have poorer survival after resection of colorectal liver metastases, although this may be confounded by various factors including advanced stage and emergency presentation.

METHODS

Medical records of consecutive patients undergoing resection of colorectal liver metastases at a single centre from 2008 to 2015 were retrospectively reviewed. Cases were categorised by primary tumour location (right colon, left colon, rectum). Each primary location was weighted using propensity scores to balance covariates, including staging and mode of presentation. Cox regression was then applied to derive multivariable hazard ratios (HR) of survival after liver resection. Primary outcomes were 10-year overall survival (OS) and 5-year disease-free survival (DFS) after liver resection based on PTL.

RESULTS

414 patients were included in the analysis. Left colonic tumours were significantly associated with higher rates of bilobar liver metastasis (36.2% vs. 20.1% and 30.1%) and larger maximum size of liver metastases compared with rectal and right-sided tumours, respectively. There was no difference in rates of extra-hepatic metastases, recurrence in the liver after resection or RAS, BRAF or p53 mutational status. After propensity weighting and Cox-regression, right-sided tumours were independently associated with significantly reduced 10 year OS (HR 1.56, 95% CI 1.03-2.36, p = 0.04) but not 5 year DFS (HR 1.36, 95% CI 0.89-2.08, p = 0.15).

CONCLUSIONS

Compared with left colonic and rectal tumours, right-sided colonic tumours are independently associated with inferior OS after resection of CRLM. This is despite higher rates of bilobar liver metastases and larger metastases with left-sided tumours.

Aortic valve biologic protheses: A cohort comparison of premature valve failure

BACKGROUND

Recent reports suggest an increased rate of early structural valve degeneration (SVD) in the Trifecta bioprosthesis (Abbott Cardiovascular). We sought to compare the intermediate-term outcomes of the Magna (Edwards Life Sciences) and Trifecta valves.

METHODS

All surgical aortic valve replacements (SAVRs) with Trifecta or Magna/Magna Ease bioprostheses at an academic medical center were extracted from an institutional database. Patients who survived until after discharge (2011-2019) were included. The primary outcome was valve failure for any reason requiring reintervention or contributing to death, identified by reintervention or review of cause of death. Time to failure was estimated with Kaplan-Meier analysis and Cox Proportional Hazards Modeling.

RESULTS

Out of 1444 patients, 521 (36%) underwent Trifecta and 923 (64%) underwent Magna implantation with a median follow-up of 27.6 months. Trifecta patients had larger median valve size (25 vs. 23 mm, p < .001) and lower median gradient (8.0 vs. 10.9 mmHg, p < .001). Trifecta patients had higher 48-month estimated failure rates (20.2 ± 7.6% vs. 2.6 ± 0.7%, p < .0001), with failure rates of 21.4 versus 9.2 failures per 1000 person-years (p < .001). After risk-adjustment, Trifecta patients had a 5.3 times hazard of failure (95% confidence interval: 2.78-12.34, p < .001) compared to Magna patients. Only Trifecta valves failed due to sudden aortic regurgitation, 8 out of 521 (1.5%).

CONCLUSION

Despite lower postoperative mean gradients, the Trifecta bioprosthesis may have an increased risk of intermediate-term SVD. Further research is warranted to confirm the potential for sudden valve failure.

Assessment of Treatment Effects and Long-term Benefits in Immune Checkpoint Inhibitor Trials Using the Flexible Parametric Cure Model: A Systematic Review

IMPORTANCE

Compared with standard cytotoxic therapies, randomized immune checkpoint inhibitor (ICI) phase 3 trials reveal delayed benefits in terms of patient survival and/or long-term response. Such outcomes generally violate the assumption of proportional hazards, and the classical Cox proportional hazards regression model is therefore unsuitable for these types of analyses.

OBJECTIVE

To evaluate the ability of the flexible parametric cure model (FPCM) to estimate treatment effects and long-term responder fractions (LRFs) independently of prespecified time points.

EVIDENCE REVIEW

This systematic review used reconstructed individual patient data from ICI advanced or metastatic melanoma and lung cancer phase 3 trials extracted from the literature. Trials published between January 1, 2010, and October 1, 2019, with long-term follow-up periods (maximum follow-up, ≥36 months in first line and ≥30 months otherwise) were selected to identify LRFs. Individual patient data for progression-free survival were reconstructed from the published randomized ICI phase 3 trial results. The FPCM was applied to estimate treatment effects on the overall population and on the following components of the population: LRF and progression-free survival in non-long-term responders. Results obtained were compared with treatment effects estimated using the Cox proportional hazards regression model.

FINDINGS

In this systematic review, among the 23 comparisons studied using the FPCM, a statistically significant association between the time-to-event component and experimental treatment was observed in the main analyses and confirmed in the sensitivity analyses of 18 comparisons. Results were discordant for 4 comparisons that were not significant by the Cox proportional hazards regression model. The LRFs varied from 1.5% to 12.7% for the control arms and from 4.6% to 38.8% for the experimental arms. Differences in LRFs varied from 2% to 29% and were significantly increased in the experimental compared with the control arms, except for 4 comparisons.

CONCLUSIONS AND RELEVANCE

This systematic review of reconstructed individual patient data found that the FPCM was a complementary approach that provided a comprehensive and pertinent evaluation of benefit and risk by assessing whether ICI treatment was associated with an increased probability of patients being long-term responders or with an improved progression-free survival in patients who were not long-term responders.

Prognostic implications of Neutrophil Extracellular Traps in coronary thrombi of patients with ST-elevation myocardial infarction

AIMS

The mechanisms of coronary thrombosis can influence prognosis after STEMI and allow for different treatment groups to be identified; an association between neutrophil extracellular traps (NETs) and unfavorable clinical outcomes has been suggested. Our aim was to determine the role played by NETs in coronary thrombosis and their influence on prognosis. The role of other histological features in prognosis and the association between NETs and bacteria in the coronary thrombi were also explored.

METHODS AND RESULTS

We studied 406 patients with STEMI in which coronary thrombi were consecutively obtained by aspiration during angioplasty between 2012 and 2018. Analysis of NETs in paraffin-embedded thrombi was based on the colocalization of specific NET components by means of confocal microscopy. Immunohistochemistry stains were used to identify plaque fragments. Fluorescence in situ hybridization was used to detect bacteria. NETs were detected in 51% of the thrombi [NET density, median (IQR): 25% (17-38%)]. The median follow-up was 47 months (95% CI 43-51); 105 (26%) patients experienced major adverse cardiac events (MACE). A significant association was found between the presence of NETs in coronary aspirates and the occurrence of MACE in the first 30 days after infarction (HR 2.82; 95% CI 1.26-6.35, p=.012), mainly due to cardiac deaths and stent thrombosis.

CONCLUSIONS

The presence of NETs in coronary thrombi was associated with a worse prognosis soon after STEMI. In some patients, NETs could be a treatment target and a feasible way to prevent reinfarction.

Prognostic model of long-term advanced stage (IIIB-IV) EGFR mutated non-small cell lung cancer (NSCLC) survivors using real-life data

BACKGROUND

There is a lack of useful diagnostic tools to identify EGFR mutated NSCLC patients with long-term survival. This study develops a prognostic model using real world data to assist clinicians to predict survival beyond 24 months.

METHODS

EGFR mutated stage IIIB and IV NSCLC patients diagnosed between January 2009 and December 2017 included in the Spanish Lung Cancer Group (SLCG) thoracic tumor registry. Long-term survival was defined as being alive 24 months after diagnosis. A multivariable prognostic model was carried out using binary logistic regression and internal validation through bootstrapping. A nomogram was developed to facilitate the interpretation and applicability of the model.

RESULTS

505 of the 961 EGFR mutated patients identified in the registry were included, with a median survival of 27.73 months. Factors associated with overall survival longer than 24 months were: being a woman (OR 1.78); absence of the exon 20 insertion mutation (OR 2.77); functional status (ECOG 0-1) (OR 4.92); absence of central nervous system metastases (OR 2.22), absence of liver metastases (OR 1.90) or adrenal involvement (OR 2.35) and low number of metastatic sites (OR 1.22). The model had a good internal validation with a calibration slope equal to 0.781 and discrimination (optimism corrected C-index 0.680).

CONCLUSIONS

Survival greater than 24 months can be predicted from six pre-treatment clinicopathological variables. The model has a good discrimination ability. We hypothesized that this model could help the selection of the best treatment sequence in EGFR mutation NSCLC patients.

Dissection of 4L lymph node for left-sided non-small cell lung cancer: a meta-analysis

BACKGROUND

Whether dissection of left lower paratracheal (4L) lymph node has any impact on survival of patients with left-sided non-small cell lung cancer (NSCLC) remains unclear. We conducted the first meta-analysis to compare the survival of patients treated with 4L lymph node dissection (LND) and those without for left-sided NSCLC.

METHODS

We systematically searched relevant studies from PubMed, Embase, and Web of Science on February 6, 2020. Data for analysis included 5-year overall survival (OS) and disease-free survival (DFS) rates, OS, and DFS. We calculated risk ratio (RR) for pooling 5-year OS and DFS rates and extracted hazard ratio (HR) from multivariate analysis for pooling OS and DFS.

RESULTS

We finally included three retrospective cohort studies with propensity score-matched analysis consisting of 2103 patients. Meta-analysis showed that patients treated with 4L LND yielded significantly higher 5-year OS (67.7% vs. 54.6%; fixed effects models: RR = 0.75; 95% confidence interval [CI] = [0.67, 0.84]; p < 0.001; I²  = 0%) and DFS (53.3% vs. 44.8%; fixed effects models: RR = 0.85; 95% CI = [0.76, 0.95]; p = 0.003; I²  = 41.7%) rates than patients without 4L LNDS. Moreover, dissection of 4L lymph node was significantly associated with better OS (fixed effects model: HR = 0.66; 95% CI = [0.57, 0.76]; p < 0.001; I²  = 45.7%) and DFS (fixed effects model: HR = 0.67; 95% CI = [0.52, 0.87]; p = 0.003; I²  = 0%). No significant heterogeneities were observed.

CONCLUSIONS

Dissection of 4L lymph node could significantly improve both 5-year OS and DFS rates and 4L LND was a favorable prognostic factor for patients with left-sided NSCLC.

Kidney Transplants in Controlled Donation Following Circulatory Death, or Maastricht Type III Donors, With Abdominal Normothermic Regional Perfusion, Optimizing Functional Outcomes

Supplemental Digital Content is available in the text.

Background.

Warm ischemia time and ischemia-reperfusion damage result in higher rates of delayed graft function and primary nonfunction in kidney transplants (KTs) from controlled donation after circulatory death (cDCD). This study aimed to assess early and late kidney function and patient and graft survival of KT from cDCD preserved with normothermic regional perfusion (NRP) and to compare with KT from brain death donors (DBDs) and cDCD preserved with rapid recovery (RR).

Methods.

Patients who received a KT at our institution from 2012 to 2018 were included, with a minimum follow-up period of 1 y. They were categorized by donor type and conditioning methods: DBD, cDCD with NRP, and cDCD with RR. Early and late graft function, along with patient and graft survival were analyzed in all groups.

Results.

A total of 182 KT recipients were included in the study (98 DBD and 84 cDCD). Out of the cDCDs, 24 kidneys were recovered with the use of NRP and 62 with RR; 22 of the 24 kidneys were ultimately transplanted. The cDCD using NRP group showed lower rates of delayed graft function compared with the cDCD with RR group (36.3% versus 46.7%, P = 0.01). Also, primary nonfunction rates were lower in the cDCD using NRP group (4.5% versus 6.4% cDCD-RR and 10.2% DBD). Patient survival rates were >90% in all groups. No differences were found in graft survival rates at 1 y.

Conclusions.

The use of abdominal NRP improves early function recovery of KT from cDCD, making their outcomes comparable with those of DBD.

Updating Reports of Phase 3 Clinical Trials for Cancer

Importance

Phase 3 randomized clinical trials (RCTs) are usually reported after a predetermined number of events (death or disease progression) have occurred, when survival curves remain poorly defined. Updated reports are important in providing mature data.

Objectives

To evaluate the proportion of phase 3 RCTs for cancer that are updated and the factors that are associated with updating them and, for updated trials, to compare initial and updated results.

Design, Setting, and Participants

This study identified reports of 2-group RCTs with a sample size of at least 100, published in 6 major journals between 1990 and 2010, that evaluated drug treatments for breast, lung, or prostate cancer. PubMed and abstracts of large cancer conferences were searched to identify updated (or earlier) reports of the same trials published up to 2019. Logistic regression was used to identify factors associated with the provision of updated reports. The hazard ratios defining the relative treatment effects for the primary and secondary end points between the initial and updated reports were compared.

Main Outcomes and Measures

Proportion of RCTs whose results are updated, factors associated with updating, and change in hazard ratio for the primary end point between initial and updated reports.

Results

A total of 207 RCTs met the inclusion criteria, and 41 (20%) were found to have updated reports. The factors significantly associated with an update included positive trial results (odds ratio [OR], 8.7 [95% CI, 3.3-23.3]), larger trial size (OR, 1.0006 [95% CI, 1.0000-1.0012]), evaluation of hormonal agents (OR, 5.8 [95% CI, 1.6-21.8]) or targeted agents (OR, 4.3 [95% CI, 1.3-14.6]) compared with chemotherapy, and evaluation of adjuvant therapy rather than therapy for advanced disease (OR, 8.0 [95% CI, 2.9-21.9]). For 31 trials for which initial and updated hazard ratios for the primary end point were available, the median hazard ratio increased from 0.66 (95% CI, 0.22-1.20) to 0.74 (95% CI, 0.32-1.19) (P < .001), indicating a decreased level of effectiveness.

Conclusions and Relevance

Only 20% of reports of phase 3 clinical trials for breast, lung, and prostate cancer were updated. Original reports of such trials are based on relatively few events, and their results are immature; more mature data indicate a decreased level of effect in updated trials. Updated reporting to provide mature, long-term results of clinical trials should be mandated.

Neoadjuvant anti-OX40 (MEDI6469) therapy in patients with head and neck squamous cell carcinoma activates and expands antigen-specific tumor-infiltrating T cells

Despite the success of checkpoint blockade in some cancer patients, there is an unmet need to improve outcomes. Targeting alternative pathways, such as costimulatory molecules (e.g. OX40, GITR, and 4-1BB), can enhance T cell immunity in tumor-bearing hosts. Here we describe the results from a phase Ib clinical trial (NCT02274155) in which 17 patients with locally advanced head and neck squamous cell carcinoma (HNSCC) received a murine anti-human OX40 agonist antibody (MEDI6469) prior to definitive surgical resection. The primary endpoint was to determine safety and feasibility of the anti-OX40 neoadjuvant treatment. The secondary objective was to assess the effect of anti-OX40 on lymphocyte subsets in the tumor and blood. Neoadjuvant anti-OX40 was well tolerated and did not delay surgery, thus meeting the primary endpoint. Peripheral blood phenotyping data show increases in CD4+ and CD8+ T cell proliferation two weeks after anti-OX40 administration. Comparison of tumor biopsies before and after treatment reveals an increase of activated, conventional CD4+ tumor-infiltrating lymphocytes (TIL) in most patients and higher clonality by TCRβ sequencing. Analyses of CD8+ TIL show increases in tumor-antigen reactive, proliferating CD103+ CD39+ cells in 25% of patients with evaluable tumor tissue (N = 4/16), all of whom remain disease-free. These data provide evidence that anti-OX40 prior to surgery is safe and can increase activation and proliferation of CD4+ and CD8+ T cells in blood and tumor. Our work suggests that increases in the tumor-reactive CD103+ CD39+ CD8+ TIL could serve as a potential biomarker of anti-OX40 clinical activity.

Different neoadjuvant therapies have been proposed to improve immunotherapy for cancer treatment. Here, the authors perform a phase Ib clinical trial where an agonist OX40 antibody provided prior to surgery is well tolerated and increases proliferation and activation of tumor antigen-specific T cells in head and neck cancer patients.

A weighted log-rank test and associated effect estimator for cancer trials with delayed treatment effect

The standard log-rank test has been extended by adopting various weight functions. Cancer vaccine or immunotherapy trials have shown a delayed onset of effect for the experimental therapy. This is manifested as a delayed separation of the survival curves. This work proposes new weighted log-rank tests to account for such delay. The weight function is motivated by the time-varying hazard ratio between the experimental and the control therapies. We implement a numerical evaluation of the Schoenfeld approximation (NESA) for the mean of the test statistic. The NESA enables us to assess the power and to calculate the sample size for detecting such delayed treatment effect and also for a more general specification of the non-proportional hazards in a trial. We further show a connection between our proposed test and the weighted Cox regression. Then the average hazard ratio using the same weight is obtained as an estimand of the treatment effect. Extensive simulation studies are conducted to compare the performance of the proposed tests with the standard log-rank test and to assess their robustness to model mis-specifications. Our tests outperform the G^ρ,γ class in general and have performance close to the optimal test. We demonstrate our methods on two cancer immunotherapy trials.

Recurrent time-to-event models with ordinal outcomes

A model to accommodate time-to-event ordinal outcomes was proposed by Berridge and Whitehead. Very few studies have adopted this approach, despite its appeal in incorporating several ordered categories of event outcome. More recently, there has been increased interest in utilizing recurrent events to analyze practical endpoints in the study of disease history and to help quantify the changing pattern of disease over time. For example, in studies of heart failure, the analysis of a single fatal event no longer provides sufficient clinical information to manage the disease. Similarly, the grade/frequency/severity of adverse events may be more important than simply prolonged survival in studies of toxic therapies in oncology. We propose an extension of the ordinal time-to-event model to allow for multiple/recurrent events in the case of marginal models (where all subjects are at risk for each recurrence, irrespective of whether they have experienced previous recurrences) and conditional models (subjects are at risk of a recurrence only if they have experienced a previous recurrence). These models rely on marginal and conditional estimates of the instantaneous baseline hazard and provide estimates of the probabilities of an event of each severity for each recurrence over time. We outline how confidence intervals for these probabilities can be constructed and illustrate how to fit these models and provide examples of the methods, together with an interpretation of the results.

Dynamic RMST curves for survival analysis in clinical trials

BACKGROUND

The data from immuno-oncology (IO) therapy trials often show delayed effects, cure rate, crossing hazards, or some mixture of these phenomena. Thus, the proportional hazards (PH) assumption is often violated such that the commonly used log-rank test can be very underpowered. In these trials, the conventional hazard ratio for describing the treatment effect may not be a good estimand due to the lack of an easily understandable interpretation. To overcome this challenge, restricted mean survival time (RMST) has been strongly recommended for survival analysis in clinical literature due to its independence of the PH assumption as well as a more clinically meaningful interpretation. The RMST also aligns well with the estimand associated with the analysis from the recommendation in ICH E-9 (R1), and the test/estimation coherency. Currently, the Kaplan Meier (KM) curve is commonly applied to RMST related analyses. Due to some drawbacks of the KM approach such as the limitation in extrapolating to time points beyond the follow-up time, and the large variance at time points with small numbers of events, the RMST may be hindered.

METHODS

The dynamic RMST curve using a mixture model is proposed in this paper to fully enhance the RMST method for survival analysis in clinical trials. It is constructed that the RMST difference or ratio is computed over a range of values to the restriction time τ which traces out an evolving treatment effect profile over time.

RESULTS

This new dynamic RMST curve overcomes the drawbacks from the KM approach. The good performance of this proposal is illustrated through three real examples.

CONCLUSIONS

The RMST provides a clinically meaningful and easily interpretable measure for survival clinical trials. The proposed dynamic RMST approach provides a useful tool for assessing treatment effect over different time frames for survival clinical trials. This dynamic RMST curve also allows ones for checking whether the follow-up time for a study is long enough to demonstrate a treatment difference. The prediction feature of the dynamic RMST analysis may be used for determining an appropriate time point for an interim analysis, and the data monitoring committee (DMC) can use this evaluation tool for study recommendation.

Breast-conserving surgery with intraoperative radiotherapy in recurrent breast cancer: the patient's perspective

Purpose

When ipsilateral breast-tumor recurrence (IBTR) following breast-conserving surgery (BCS) occurs, the cure of a potentially life-threatening disease is the main goal. If, however, this is diagnosed early, prognosis is still good and patient-reported outcomes become more important. Despite the fact that many patients would prefer a further BCS, international breast cancer guidelines still recommend mastectomy, mainly because previous radiation implies limited options. Our comparative study evaluates the long-term quality-of-life and outcome in patients with IBTR who received BCS plus intraoperative radiotherapy (IORT) versus mastectomy.

Methods

Patients with IBTR were retrospectively divided into three groups according to the local treatment: group 1 (n = 26) was treated with BCS + IORT; group 2 (n = 35) received a standard mastectomy; group 3 (n = 52) had a mastectomy with subsequent reconstruction. Outcomes were analyzed after a mean follow-up of 5 years after IBTR. Quality-of-life was evaluated by the validated questionnaire BREAST-Q in 50 patients who fulfilled the inclusion criteria.

Results

Quality-of-life scores varied within the groups, ranging from 51.4 to 91.3 (out of 100 points). We observed satisfactory scores in all items, with no statistical difference within the groups. Disease-free survival of all groups did not statistically differ, and overall mortality was very low (0.9%). The postinterventional complication rate was lower after BCS (19.2% versus 34.3% after mastectomy and 30.8% after mastectomy with reconstruction).

Conclusion

For patients with previous surgery and radiation who demand a second BCS in the recurrent situation, this surgical technique can be offered in combination with IORT. Our long-term results imply oncological safety, lower complication rate, and good patient satisfaction.

Survival and cardiac toxicity in patients with HER2-positive, metastatic breast cancer treated with trastuzumab in routine clinical practice

AIMS

We sought to describe survival outcomes and toxicities of trastuzumab in real-world patients with HER2-positive, metastatic breast cancer (MBC) and compare these to a recent systematic review of clinical trials.

METHODS

We searched the medical records of three Sydney cancer centers for patients with HER2-positive, MBC starting trastuzumab from January 2001 to March 2017. We recorded patient, tumor, and treatment characteristics; survival times from start of palliative trastuzumab; and rates of cardiac toxicity. Survival distribution was summarized using the following percentiles (represented scenario): 90th (worst-case), 75th (lower-typical), 25th (upper-typical), and 10th (best-case). Survival times were compared to recent review of HER2-positive MBC randomized trials. Factors associated with survival were assessed with Cox models.

RESULTS

Characteristics of the 126 patients were: median age 53 years, ER positive cancer (50%), de-novo metastatic disease (23%), prior adjuvant trastuzumab (15%), liver metastases (37%), and brain metastases (23%). The median duration of first-line trastuzumab was 11 months (interquartile range, (IQR) 5-27). Survival times in months (vs the systematic review) were: 90th percentile 8 (9); 75th percentile 16 (19); and median 34 (33). Follow-up duration was insufficient to estimate the 25th and 10th percentiles, similar to the systematic review. Liver metastases were associated with shorter survival (HR = 1.74, 95% CI, 1.1-2.76, P = .02). Seventy percent of patients had a baseline cardiac assessment. Five patients (3.9%) developed symptomatic cardiac toxicity, similar to clinical trials.

CONCLUSION

Survival and cardiac toxicity rates for women starting trastuzumab in routine practice were comparable to clinical trials. Oncologists can use clinical trial data as a reference point when explaining survival outcomes to women with HER2-positive MBC.

Addition of Docetaxel to Oral Fluoropyrimidine Improves Efficacy in Patients With Stage III Gastric Cancer: Interim Analysis of JACCRO GC-07, a Randomized Controlled Trial

PURPOSE

S-1 is a standard postoperative adjuvant chemotherapy for patients with stage II or III gastric cancer in Asia. Neoadjuvant or perioperative strategies dominate in Western countries, and docetaxel has recently shown significant survival benefits when combined with other standard regimens in advanced cancer and perioperative settings.

PATIENTS AND METHODS

This randomized phase III study was designed to prove the superiority of postoperative S-1 plus docetaxel over S-1 alone for R0 resection of pathologic stage III gastric cancer. The sample size of 1,100 patients was necessary to detect a 7% increase in 3-year relapse-free survival as the primary end point (hazard ratio, 0.78; 2-sided α = .05; β = .2).

RESULTS

The second interim analysis was conducted when the number of events reached 216 among 915 enrolled patients (median follow-up, 12.5 months). Analysis demonstrated the superiority of S-1 plus docetaxel (66%) to S-1 (50%) for 3-year relapse-free survival (hazard ratio, 0.632; 99.99% CI, 0.400 to 0.998; stratified log-rank test, P < .001), and enrollment was terminated as recommended by the independent data and safety monitoring committee. Incidences of grade 3 or greater adverse events, particularly neutropenia and leukopenia, were higher in the S-1 plus docetaxel group, but all events were manageable.

CONCLUSION

Addition of docetaxel to S-1 is effective with few safety concerns in patients with stage III gastric cancer. The present findings may also be applicable in countries in which perioperative adjuvant chemotherapy or chemoradiation is not standard.

Minimally Invasive versus Abdominal Radical Hysterectomy for Cervical Cancer

BACKGROUND

There are limited data from retrospective studies regarding whether survival outcomes after laparoscopic or robot-assisted radical hysterectomy (minimally invasive surgery) are equivalent to those after open abdominal radical hysterectomy (open surgery) among women with early-stage cervical cancer.

METHODS

In this trial involving patients with stage IA1 (lymphovascular invasion), IA2, or IB1 cervical cancer and a histologic subtype of squamous-cell carcinoma, adenocarcinoma, or adenosquamous carcinoma, we randomly assigned patients to undergo minimally invasive surgery or open surgery. The primary outcome was the rate of disease-free survival at 4.5 years, with noninferiority claimed if the lower boundary of the two-sided 95% confidence interval of the between-group difference (minimally invasive surgery minus open surgery) was greater than -7.2 percentage points (i.e., closer to zero).

RESULTS

A total of 319 patients were assigned to minimally invasive surgery and 312 to open surgery. Of the patients who were assigned to and underwent minimally invasive surgery, 84.4% underwent laparoscopy and 15.6% robot-assisted surgery. Overall, the mean age of the patients was 46.0 years. Most patients (91.9%) had stage IB1 disease. The two groups were similar with respect to histologic subtypes, the rate of lymphovascular invasion, rates of parametrial and lymph-node involvement, tumor size, tumor grade, and the rate of use of adjuvant therapy. The rate of disease-free survival at 4.5 years was 86.0% with minimally invasive surgery and 96.5% with open surgery, a difference of -10.6 percentage points (95% confidence interval [CI], -16.4 to -4.7). Minimally invasive surgery was associated with a lower rate of disease-free survival than open surgery (3-year rate, 91.2% vs. 97.1%; hazard ratio for disease recurrence or death from cervical cancer, 3.74; 95% CI, 1.63 to 8.58), a difference that remained after adjustment for age, body-mass index, stage of disease, lymphovascular invasion, and lymph-node involvement; minimally invasive surgery was also associated with a lower rate of overall survival (3-year rate, 93.8% vs. 99.0%; hazard ratio for death from any cause, 6.00; 95% CI, 1.77 to 20.30).

CONCLUSIONS

In this trial, minimally invasive radical hysterectomy was associated with lower rates of disease-free survival and overall survival than open abdominal radical hysterectomy among women with early-stage cervical cancer. (Funded by the University of Texas M.D. Anderson Cancer Center and Medtronic; LACC ClinicalTrials.gov number, NCT00614211 .).