Group sequential adaptive designs in series of time-to-event randomised trials in rare diseases: A simulation study.

In rare diseases, fully powered large trials may not be doable in a reasonable time frame even with international collaborations. In a previous work, we proposed an approach based on a series of smaller parallel group two-arm randomised controlled trials (RCT) performed over a long research horizon. Within the series of trials, the treatment selected after each trial becomes the control treatment of the next one. We concluded that running more trials with smaller sample sizes and relaxed α-levels leads in the long term and under reasonable assumptions to larger survival benefits with a moderate increase of risk as compared to traditional designs based on larger but fewer trials designed to meet stringent evidence criteria. We now extend this quantitative framework with more 'flexible' designs including interim analyses for futility and/or efficacy, and three-arm adaptive designs with treatment selection at interim. In the simulation study, we considered different disease severities, accrual rates, and hypotheses of how treatments improve over time. For each design, we estimated the long-term survival benefit as the relative difference in hazard rates between the end and the start of the research horizon, and the risk defined as the probability of selecting at the end of the research horizon a treatment inferior to the initial control. We assessed the impact of the α-level and the choice of the stopping rule on the operating characteristics. We also compared the performance of series based on two- vs. three-arm trials. We show that relaxing α-levels within the limit of 0.1 is associated with larger survival gains and moderate increase of risk which remains within acceptable ranges. Including an interim analysis with a futility rule is associated with an additional survival gain and a better risk control as compared to series with no interim analysis, when the α-level is below or equal to 0.1, whereas the benefit of including an interim analysis is rather small for higher α-levels. Including an interim analysis for efficacy yields almost no additional gain. Series based on three-arm trials are associated with a systematic improvement in terms of survival gain and risk control as compared to series of two-arm trials.

No evidence for changes in skeletal muscle mass or weight during first-line chemotherapy for metastatic colorectal cancer.

BACKGROUND: Studies over the past 10 years strongly support an association between skeletal muscle mass (SMM) depletion and outcome in metastatic colorectal cancer (mCRC). Factors influencing SMM changes over time are, however, poorly studied. We analyzed the impact of SMM on overall survival and chemotherapy toxicities in mCRC patients treated with first-line chemotherapy. Changes in weight and body composition were evaluated during follow-up. METHODS: Patients enrolled in the randomized phase II ACCORD trial comparing two chemotherapy regimens were screened. Body composition parameters (SMM, adipose tissue) were assessed prospectively with computed tomography (CT) imaging, and toxicities were recorded. Mixed models were used to assess weight and BC changes during 4 months of treatment follow-up. RESULTS: Among 145 patients included in ACCORD, 76 had available baseline CT scans and were included in the current study. Mean age was 60.6 ± 10.0 years, 50% were women, 82% had colon cancer, and 62% had two or more metastatic sites. At baseline, 49% had lost at least 5% of their initial weight, including 26% who had lost more than 10%; 53% had SMM depletion. In this homogenous cohort, there were no statistically significant associations between SMM depletion and overall survival, progression-free survival or chemotherapy toxicity. There were no decreases in weight or SMM during follow-up. Weight and SMM changes were not influenced by diarrhea either grade 3-4 or any grade (reported in 74% of patients). For patients with weight loss ≥10% at baseline, SMM increased significantly after 4 months of follow-up and after disease stabilization following chemotherapy (P = 0.008). CONCLUSIONS: In a homogenous mCRC cohort, SMM depletion was not associated with survival or chemotherapy toxicity. Despite most patient experiencing diarrhea, no changes in weight or SMM were found during 4 months of follow-up. However, hypotheses deriving from our exploratory study have to be tested in further larger sample size studies. TRIAL REGISTRATION: Clinicaltrials.gov NCT00423696 (2011).

CRM2DIM: A SAS macro for implementing the dual-agent Bayesian continual reassessment method.

BACKGROUND AND OBJECTIVE: The continual reassessment method (CRM) is a model-based dose-finding design for single-agent phase I oncology trials. With the advance of targeted therapies in oncology, more and more phase I trials investigate drug combinations rather than a single agent in order to find one or more maximum tolerated dose combinations. Several designs have been proposed for such dose-finding trials but only a few software packages are available to implement them. One of the designs is the two-dimensional Bayesian CRM proposed by Wang and Ivanova. Our goal was to provide an easy-to-use program to implement this design. METHODS: We developed a new SAS macro, CRM2DIM, for implementing this design. This macro can be used to run a phase I dose-finding trial for two-drug combination and to perform simulations. RESULTS: We describe the program with its different features, including the possibility of running an initial design (start-up rule), the possibility of incorporating historical data, and the choice of using either a power or a logistic regression model with or without interaction term. We illustrate our program by presenting simulation results and by a hypothetical trial example. CONCLUSIONS: The CRM2DIM macro provides a SAS implementation of the two-dimensional Bayesian CRM for dual-agent phase I oncology trials. It is an easy-to-use program that includes many useful features and provides statisticians involved in the early phases of development a new tool for designing dual-agent phase I oncology trials.

A new prognostic model for survival in second line for metastatic renal cell carcinoma: development and external validation.

BACKGROUND: In patients with metastatic renal cell carcinoma (mRCC), the oncologic benefit of second-line treatment for high volume tumors or presence of more than five risk factors remain to be defined. Our aim was to develop and externally validate a new model most likely to correctly predict overall survival (OS) categories in second line. METHOD: mRCC patients treated within clinical trials at Gustave Roussy Cancer Campus (GRCC) formed the discovery set. Patients from two phase III trials from Pfizer database (PFIZERDB), AXIS (NCT00678392), and INTORSECT (NCT00474786), formed the external validation set. New prognostic factors were analyzed using a multivariable Cox model with a backward selection procedure. Performance of the GRCC model and the prognostic classification scheme derived from it, measuring by R2, c-index, and calibration, was evaluated on the validation set and compared to MSKCC and IMDC models. RESULTS: Two hundred and twenty-one patients were included in the GRCC cohort and 855 patients in the PFIZERDB. Median OS was similar in the discovery and validation cohorts (16.8 [95% CI 12.9-21.7] and 15.3 [13.6-17.2] months, respectively). Backward selection procedure identified time from first to second-line treatment and tumor burden as new independent prognostic factors significantly associated to OS after adjusting for IMDC prognostic factors (HR 1.68 [1.23-2.31] and 1.43 [1.03-1.99], respectively). Dividing patients into four risk groups, based on the number of factors selected in GRCC model, median OS from the start of second line in the validation cohort was not reached (NE) [95% CI 24.9-NE] in the favorable risk group (n = 20), 21.8 months [18.6-28.2] in the intermediate-risk group (n = 367), 12.7 months [11.0-15.8] in the low poor-risk group (n = 347), and 5.5 months [4.7-6.4] in the high poor-risk group (n = 121). Finally, this model and its prognostic classification scheme provided the better fit, with higher R2 and higher c-index compared to other possible classification schemes. CONCLUSION: A new prognostic model was developed and validated to estimate overall survival of patients with previously treated mRCC. This model is an easy-to-use tool that allows accurate estimation of patient survival to inform decision making and follow-up after first line for mRCC.

Cyclin E1 Expression and Palbociclib Efficacy in Previously Treated Hormone Receptor-Positive Metastatic Breast Cancer.

PURPOSE: A large-panel gene expression analysis was conducted to identify biomarkers associated with the effectiveness of adding palbociclib to fulvestrant. METHODS: The PALOMA-3 ( ClinicalTrials.gov identifier: NCT01942135) trial randomly assigned 521 endocrine-pretreated patients with metastatic breast cancer to receive palbociclib plus fulvestrant or placebo plus fulvestrant. Primary analysis was first conducted on 10 genes on the basis of pathway biology and evidence from previous studies followed by a systematic panel-wide search among 2,534 cancer-related genes. The association of gene expression with the effect of palbociclib on progression-free survival (PFS) was evaluated using Cox proportional hazards regression analysis, with gene expression as a continuous variable or dichotomized by median. An independent breast cancer cohort from the Preoperative Palbociclib (POP) Clinical Trial ( ClinicalTrials.gov identifier: NCT02008734) was used for validation, in 61 patients with primary breast cancer treated with 2 weeks of palbociclib. RESULTS: In the PALOMA-3 trial, 302 patients had tumor tissue analyzed (palbociclib arm, 194 patients; placebo arm, 108 patients). Palbociclib efficacy was lower in patients with high versus low cyclin E1 (CCNE1) mRNA expression (median PFS: palbociclib arm, 7.6 v 14.1 months; placebo arm, 4.0 v 4.8 months, respectively; interaction P unadjusted = .00238; false discovery rate-adjusted P = .0238). CCNE1 mRNA was more predictive in metastatic than in archival primary biopsy tissue samples. No significant interaction was found between treatment and expression levels of CDK4, CDK6, cyclin D1, and RB1. Palbociclib was efficacious in both luminal A and luminal B tumors. High CCNE1 mRNA expression was associated with poor antiproliferative activity of palbociclib in the POP trial (P = .005). CONCLUSION: Addition of palbociclib to fulvestrant demonstrated efficacy in all biomarker groups, although high CCNE1 mRNA expression was associated with relative resistance to palbociclib.

Daily Versus Weekly Prostate Cancer Image Guided Radiation Therapy: Phase 3 Multicenter Randomized Trial.

PURPOSE: The optimal frequency of prostate cancer image guided radiation therapy (IGRT) has not yet been clearly identified. This study sought to compare the safety and efficacy of daily versus weekly IGRT. MATERIALS AND METHODS: This phase 3 randomized trial recruited patients with N0 localized prostate cancer. The total IGRT doses in the prostate ranged from 70 Gy to 80 Gy, sparing the lymph nodes. Patients were randomly assigned (1:1) to 2 prostate IGRT frequency groups: daily and weekly (ie, on days 1, 2, and 3 and then weekly). The primary outcome was 5-year recurrence-free survival. Secondary outcomes included overall survival and toxicity. Post hoc analyses included biochemical progression-free interval, clinical progression-free interval, and other cancer-free interval. RESULTS: Between June 2007 and November 2012, 470 men from 21 centers were randomized into the 2 groups. Median follow-up was 4.1 years. There was no statistically significant difference in recurrence-free survival between the groups (hazard ratio [HR] = 0.81; P = .330). Overall survival was worse in the daily group than in the weekly group (HR = 2.12 [95% confidence interval (CI), 1.03-4.37]; P = .042). Acute rectal bleeding (grade ≥1) was significantly lower in the daily group (6%) (n = 14) than in the weekly group (11%) (n = 26) (P = .014). Late rectal toxicity (grade ≥1) was significantly lower in the daily group (HR = 0.71 [95% CI, 0.53-0.96]; P = .027). Biochemical progression-free interval (HR = 0.45 [95% CI, 0.25 - 0.80]; P = .007) and clinical progression-free interval (HR = 0.50 [95% CI, 0.24-1.02]; P = .057) were better in the daily group, whereas other cancer-free interval was worse in the daily group (HR = 2.21 [95% CI, 1.10-4.44]; P = .026). CONCLUSIONS: Compared with weekly control, daily IGRT control in prostate cancer significantly improves biochemical progression-free and clinical progression-free interval, and rectal toxicity.

ER+ Breast Cancers Resistant to Prolonged Neoadjuvant Letrozole Exhibit an E2F4 Transcriptional Program Sensitive to CDK4/6 Inhibitors.

Purpose: This study aimed to identify biomarkers of resistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancers treated with prolonged neoadjuvant letrozole.Experimental Design: We performed targeted DNA and RNA sequencing in 68 ER+ breast cancers from patients treated with preoperative letrozole (median, 7 months).Results: Twenty-four tumors (35%) exhibited a PEPI score ≥4 and/or recurred after a median of 58 months and were considered endocrine resistant. Integration of the 47 most upregulated genes (log FC > 1, FDR < 0.03) in letrozole-resistant tumors with transcription-binding data showed significant overlap with 20 E2F4-regulated genes (P = 2.56E-15). In patients treated with the CDK4/6 inhibitor palbociclib before surgery, treatment significantly decreased expression of 24 of the 47 most upregulated genes in letrozole-resistant tumors, including 18 of the 20 E2F4 target genes. In long-term estrogen-deprived ER+ breast cancer cells, palbociclib also downregulated all 20 E2F4 target genes and P-RB levels, whereas the ER downregulator fulvestrant or paclitaxel only partially suppressed expression of this set of genes and had no effect on P-RB. Finally, an E2F4 activation signature was strongly associated with resistance to aromatase inhibitors in the ACOSOG Z1031B neoadjuvant trial and with an increased risk of relapse in adjuvant-treated ER+ tumors in METABRIC.Conclusions: In tumors resistant to prolonged neoadjuvant letrozole, we identified a gene expression signature of E2F4 target activation. CDK4/6 inhibition suppressed E2F4 target gene expression in estrogen-deprived ER+ breast cancer cells and in patients' ER+ tumors, suggesting a potential benefit of adjuvant CDK4/6 inhibitors in patients with ER+ breast cancer who fail to respond to preoperative estrogen deprivation. Clin Cancer Res; 24(11); 2517-29. ©2018 AACR.

Factors which modulate the rates of skeletal muscle mass loss in non-small cell lung cancer patients: a pilot study.

PURPOSE: Advanced non-small cell lung cancer (NSCLC) is associated with weight loss which may reflect skeletal muscle mass (SMM) and/or total adipose tissue (TAT) depletion. This study aimed to describe changes in body composition (BC) parameters and to identify the factors unrelated to the tumor which modulate them. METHODS: SMM, TAT, and the proportion of SMM to SMM + TAT were assessed with computed tomography. Estimates of each BC parameter at follow-up initiation and across time were derived from a mixed linear model of repeated measurements with a random intercept and a random slope. The same models were used to assess the independent effect of gender, age, body mass index (BMI), and initial values on changes in each BC parameter. RESULTS: Sixty-four patients with stage III or IV NSCLC were reviewed. The mean ± SD decreases in body weight and SMM were respectively 59 ± 3 g/week (P < 0.03) and 7 mm2/m2/week (P = 0.0003). During follow-up, no changes were identified in TAT nor in muscle density or in the proportion of SMM to SMM + TAT, estimated at 37 ± 2% at baseline. SMM loss was influenced by initial BMI (P < 0.0001) and SMM values (P = 0.0002): the higher the initial BMI or SMM values, the greater the loss observed. Weight loss was greater when the initial weight was heavier (P < 0.0001). CONCLUSION: Our results demonstrate that SMM wasting in NSCLC is lower when initial SMM and BMI values are low. These exploratory findings after our attempt to better understand the intrinsic factors associated with muscle mass depletion need to be confirmed in larger studies.

Integrating Tenascin-C protein expression and 1q25 copy number status in pediatric intracranial ependymoma prognostication: A new model for risk stratification.

PURPOSE: Despite multimodal therapy, prognosis of pediatric intracranial ependymomas remains poor with a 5-year survival rate below 70% and frequent late deaths. EXPERIMENTAL DESIGN: This multicentric European study evaluated putative prognostic biomarkers. Tenascin-C (TNC) immunohistochemical expression and copy number status of 1q25 were retained for a pooled analysis of 5 independent cohorts. The prognostic value of TNC and 1q25 on the overall survival (OS) was assessed using a Cox model adjusted to age at diagnosis, tumor location, WHO grade, extent of resection, radiotherapy and stratified by cohort. Stratification on a predictor that did not satisfy the proportional hazards assumption was considered. Model performance was evaluated and an internal-external cross validation was performed. RESULTS: Among complete cases with 5-year median follow-up (n = 470; 131 deaths), TNC and 1q25 gain were significantly associated with age at diagnosis and posterior fossa tumor location. 1q25 status added independent prognostic value for death beyond the classical variables with a hazard ratio (HR) = 2.19 95%CI = [1.29; 3.76] (p = 0.004), while TNC prognostic relation was tumor location-dependent with HR = 2.19 95%CI = [1.29; 3.76] (p = 0.004) in posterior fossa and HR = 0.64 [0.28; 1.48] (p = 0.295) in supratentorial (interaction p value = 0.015). The derived prognostic score identified 3 different robust risk groups. The omission of upfront RT was not associated with OS for good and intermediate prognostic groups while the absence of upfront RT was negatively associated with OS in the poor risk group. CONCLUSION: Integrated TNC expression and 1q25 status are useful to better stratify patients and to eventually adapt treatment regimens in pediatric intracranial ependymoma.

Statistical approaches for evaluating body composition markers in clinical cancer research.

INTRODUCTION: The term 'morphomics' stands for the markers of body composition in muscle and adipose tissues. in recent years, as part of clinical cancer research, several associations between morphomics and outcome or toxicity were found in different treatment settings leading to a growing interest. we aim to review statistical approaches used to evaluate these markers and suggest practical statistical recommendations. Area covered: We identified statistical methods used recently to take into account properties of morphomics measurements. We also reviewed adjustment methods on major confounding factors such as gender and approaches to model morphomic data, especially mixed models for repeated measures. Finally, we focused on methods for determining a cut-off for a morphomic marker that could be used in clinical practice and how to assess its robustness. Expert commentary: From our review, we proposed 13 key points to strengthen analyses and reporting of clinical research assessing associations between morphomics and outcome or toxicity.

Sarcopenia is Associated with Chemotherapy Toxicity in Patients Undergoing Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Carcinomatosis from Colorectal Cancer.

BACKGROUND: Despite the positive survival results of cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC), criticisms have been put forward regarding the safety of this treatment as a result of a high morbidity rate. Muscle depletion (sarcopenia) is associated with the occurrence of postoperative complications. The purpose of this study was to determine the association between sarcopenia and postoperative morbidity after CRS-HIPEC for peritoneal carcinomatosis from colorectal cancer by distinguishing the complications linked to CRS itself and those associated with chemotherapy (HIPEC) toxicities. METHODS: Data concerning 97 consecutive patients who had undergone CRS-HIPEC were recorded. We analyzed the events occurring within 30 days after surgery that were prospectively recorded in a database. Sarcopenia was assessed using the L3 muscle index on computed tomography performed during the 2 months preceding surgery. RESULTS: The sarcopenic patients experienced significantly more chemotherapy toxicities (57 vs. 26 %; p = 0.004) and especially neutropenia (36 vs. 17 %; p = 0.04) than their nonsarcopenic counterparts. There was no difference in complications linked to the CRS procedure between sarcopenic and nonsarcopenic patients. In the multivariate analysis, sarcopenia was the only parameter independently associated with the risk of chemotherapy toxicity (odds ratio 3.97; 95 % confidence interval 1.52-10.39; p = 0.005). CONCLUSIONS: Despite the local administration of chemotherapy, systemic toxicity was observed in sarcopenic patients after CRS-HIPEC. This relationship favors new treatment strategies with white blood cell growth factors or chemotherapy dosing based on muscle value.

New insights into the evaluation of randomized controlled trials for rare diseases over a long-term research horizon: a simulation study.

Large sample sizes are required in randomized clinical trials designed to meet typical one-sided 2.5% α-level and 80% power. This may not be achievable when the disease is rare. We simulated a series of two-arm superiority trials over a 15-year period. The design parameters examined were the α-level and the number of trials conducted over the 15-year period (thus, trial sample size). Different disease severities and accrual rates were considered. The future treatment effect was characterized by its associated hazard rate; different hypotheses of how treatments improve over time were considered. We defined the total survival benefit as the relative difference of the hazard rates at year 15 versus year 0. The optimal design was defined by maximizing the expected total survival benefit, provided that the risk of selecting at year 15 a treatment inferior to the initial control treatment remains below 1%. Compared with two larger trials with typical one-sided 2.5% α-level, performing a series of small trials with relaxed α-levels leads on average to larger survival benefits over a 15-year research horizon, but also to higher risk of selecting a worse treatment at the end of the research period. Under reasonably optimistic assumptions regarding the future treatment effects, optimal designs outperform traditional ones when the disease is severe (baseline median survival ≤ 1 year) and the accrual is ≥100 patients per year, whereas no major improvement is observed in diseases with better prognosis. Trial designs aiming to maximize survival gain over a long research horizon across a series of trials are worth discussing in the context of rare diseases. Copyright © 2016 John Wiley & Sons, Ltd.

Phase I trial evaluating the antiviral agent Cidofovir in combination with chemoradiation in cervical cancer patients.

PURPOSE: This phase I trial aimed to assess the safety and determine the recommended Phase II dose (RP2D) of Cidofovir combined with chemoradiotherapy in patients with stage IB2-IVA cervical cancer. EXPERIMENTAL DESIGN: Incremental doses (1, 2.5, 5 and 6.5 mg/kg) of IV Cidofovir were administered weekly for two weeks, and then every 2 weeks from the start of chemoradiotherapy to the initiation of utero-vaginal brachytherapy. Biological expression of HPV was analyzed during treatment and tumor response was assessed according to RECIST v1.0 criteria. RESULTS: A total of 15 patients were treated with Cidofovir. Dose-limiting toxicities occurred in 2/6 patients at the 6.5 mg/kg dose level (G3 proteinuria, and G3 acute pyelonephritis with G3 febrile neutropenia). No toxicity occurred at the 5 mg/kg dose level, but only 3 patients received this dose due to trial interruption because of low accrual. The most frequent G3-4 adverse effects observed during the trial were: abdominal pain (n=3), infection (n=2), leuckoneutropenia (n=2), and others (n=6). No toxic death or major renal side effect occurred. The best response was that 8/9 evaluable patients achieved a complete response (89%). In the intention to treat population, the 2-year overall and progression-free survival rates were 93% and 76%, respectively. Biological monitoring of HPV-related markers (decreased p16 expression, and increased p53 and pRb levels) was possible on sequential tumor biopsy samples. The genomic alterations identified were PIK3CA (n=5; one also had a KRAS mutation), and HRAS (n=1) mutations. CONCLUSIONS: Cidofovir at a dose of 5mg/kg combined with chemoradiotherapy appeared tolerable and yielded tumor regressions. Due to early trial interruption, the RP2D was not confirmed.