scholarly journals A Bayesian non-inferiority approach using experts’ margin elicitation – application to the monitoring of safety events

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Camille Aupiais ◽  
Corinne Alberti ◽  
Thomas Schmitz ◽  
Olivier Baud ◽  
Moreno Ursino ◽  
...  

Abstract Background When conducing Phase-III trial, regulatory agencies and investigators might want to get reliable information about rare but serious safety outcomes during the trial. Bayesian non-inferiority approaches have been developed, but commonly utilize historical placebo-controlled data to define the margin, depend on a single final analysis, and no recommendation is provided to define the prespecified decision threshold. In this study, we propose a non-inferiority Bayesian approach for sequential monitoring of rare dichotomous safety events incorporating experts’ opinions on margins. Methods A Bayesian decision criterion was constructed to monitor four safety events during a non-inferiority trial conducted on pregnant women at risk for premature delivery. Based on experts’ elicitation, margins were built using mixtures of beta distributions that preserve experts’ variability. Non-informative and informative prior distributions and several decision thresholds were evaluated through an extensive sensitivity analysis. The parameters were selected in order to maintain two rates of misclassifications under prespecified rates, that is, trials that wrongly concluded an unacceptable excess in the experimental arm, or otherwise. Results The opinions of 44 experts were elicited about each event non-inferiority margins and its relative severity. In the illustrative trial, the maximal misclassification rates were adapted to events’ severity. Using those maximal rates, several priors gave good results and one of them was retained for all events. Each event was associated with a specific decision threshold choice, allowing for the consideration of some differences in their prevalence, margins and severity. Our decision rule has been applied to a simulated dataset. Conclusions In settings where evidence is lacking and where some rare but serious safety events have to be monitored during non-inferiority trials, we propose a methodology that avoids an arbitrary margin choice and helps in the decision making at each interim analysis. This decision rule is parametrized to consider the rarity and the relative severity of the events and requires a strong collaboration between physicians and the trial statisticians for the benefit of all. This Bayesian approach could be applied as a complement to the frequentist analysis, so both Data Safety Monitoring Boards and investigators can benefit from such an approach.

1991 ◽  
Vol 02 (03) ◽  
pp. 221-228 ◽  
Author(s):  
Lluís Garrido ◽  
Vicens Gaitan

We have tested a neural network (NN) technique as a method to determine the helicity of the τ particles in the process: e+e−→(Z0, γ*)→τ+τ−→(ρν)(ρν). It takes into account in a natural way the fact that both taus have different helicity and gives efficiencies comparable to the Bayesian method. We have found this “academic” example a nice way to introduce the analytical interpretation of the net output, showing that these neural nets techniques are equivalent to a Bayesian Decision Rule.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jing Cheng ◽  
Beibei Liu ◽  
Biao Wang ◽  
Xicui Long ◽  
Zhihong Li ◽  
...  

Abstract Background Cervical cancer is a common malignancy of the female genital tract. Treatment options for cervical cancer patients diagnosed at FIGO (2009) stage IB2 and IIA2 remains controversial. Methods We perform a Bayesian network meta-analysis to directly or indirectly compare various interventions for FIGO (2009) IB2 and IIA2 disease, in order to improve our understand of the optimal treatment strategy for these women. Three databases were searched for articles published between 1971 and 2020. Data on included study characteristics, outcomes, and risk of bias were abstracted by two reviewers. Results Seven thousand four hundred eighty-six articles were identified. Thirteen randomized controlled trials of FIGO (2009) IB2 and IIA2 cervical cancer patients were included in the final analysis. These trials used six different interventions: concomitant chemoradiotherapy (CCRT), radical surgery (RS), radical surgery following chemoradiotherapy (CCRT+RS), neoadjuvant chemotherapy followed by radical surgery (NACT+RS), adjuvant radiotherapy followed by Radical surgery (RT + RS), radiotherapy alone (RT).SUCRA ranking of OS and Relapse identified CCRT+RS and CCRT as the best interventions, respectively. Systematic clustering analysis identified the CCRT group as a unique cluster. Conclusion These data suggest that CCRT may be the best approach for improving the clinical outcome of cervical cancer patients diagnosed at FIGO (2009) stage IB2/IIA2. Phase III randomized trials should be performed in order to robustly assess the relative efficacy of available treatment strategies in this disease context.


2013 ◽  
Vol 31 (5) ◽  
pp. 616-622 ◽  
Author(s):  
Antoni Ribas ◽  
Richard Kefford ◽  
Margaret A. Marshall ◽  
Cornelis J.A. Punt ◽  
John B. Haanen ◽  
...  

PurposeIn phase I/II trials, the cytotoxic T lymphocyte–associated antigen-4–blocking monoclonal antibody tremelimumab induced durable responses in a subset of patients with advanced melanoma. This phase III study evaluated overall survival (OS) and other safety and efficacy end points in patients with advanced melanoma treated with tremelimumab or standard-of-care chemotherapy.Patients and MethodsPatients with treatment-naive, unresectable stage IIIc or IV melanoma were randomly assigned at a ratio of one to one to tremelimumab (15 mg/kg once every 90 days) or physician's choice of standard-of-care chemotherapy (temozolomide or dacarbazine).ResultsIn all, 655 patients were enrolled and randomly assigned. The test statistic crossed the prespecified futility boundary at second interim analysis after 340 deaths, but survival follow-up continued. At final analysis with 534 events, median OS by intent to treat was 12.6 months (95% CI, 10.8 to 14.3) for tremelimumab and 10.7 months (95% CI, 9.36 to 11.96) for chemotherapy (hazard ratio, 0.88; P = .127). Objective response rates were similar in the two arms: 10.7% in the tremelimumab arm and 9.8% in the chemotherapy arm. However, response duration (measured from date of random assignment) was significantly longer after tremelimumab (35.8 v 13.7 months; P = .0011). Diarrhea, pruritus, and rash were the most common treatment-related adverse events in the tremelimumab arm; 7.4% had endocrine toxicities. Seven deaths in the tremelimumab arm and one in the chemotherapy arm were considered treatment related by either investigators or sponsor.ConclusionThis study failed to demonstrate a statistically significant survival advantage of treatment with tremelimumab over standard-of-care chemotherapy in first-line treatment of patients with metastatic melanoma.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 516-516
Author(s):  
Matteo Lambertini ◽  
Luca Boni ◽  
Andrea Michelotti ◽  
Emanuela Magnolfi ◽  
Alessio Aligi Cogoni ◽  
...  

516 Background: Current guidelines recommend GnRH agonist (GnRHa) use during chemotherapy (CT) as a strategy to reduce the risk of premature ovarian insufficiency (POI) in premenopausal patients with early breast cancer (EBC). However, no long-term safety data are available raising some concerns on concurrent use of GnRHa during CT in patients with hormone receptor-positive disease. In addition, there is no evidence on the protective role of this strategy in patients with germline BRCA mutations ( mBRCA). Here, we report the final analysis of the PROMISE-GIM6 phase III randomized study, the largest trial addressing the role of GnRHa use during CT in premenopausal EBC patients (Del Mastro et al, JAMA 2011 & Lambertini et al, JAMA 2015). Methods: From October 2003 to January 2008, 281 premenopausal patients aged 18 to 45 years with stage I-III EBC candidates for (neo)adjuvant CT were randomized to receive CT alone or combined with the GnRHa triptorelin. Primary endpoint was incidence of CT-induced POI (defined as amenorrhea and post-menopausal FSH/estradiol levels 1 year following CT). This final analysis reports on post-treatment pregnancies, disease-free survival (DFS) and overall survival (OS). An exploratory descriptive analysis in mBRCA patients is also reported. (ClinicalTrial.gov: NCT00311636) Results: Of the 281 randomized patients (CT+GnRHa arm = 148; CT alone arm = 133), 80% had hormone receptor-positive disease. At the time of this final analysis, 38 (13.5%) patients were lost to follow-up. Median follow-up was 12.4 years (IQR: 11.3-13.2 years). In the CT+GnRHa and CT alone arms, respectively, 9 (10-year cumulative incidence of pregnancy 6.5%, 95% CI 3.5%-12.3%) and 4 (10-year cumulative incidence of pregnancy 3.2%, 95% CI 1.2%-8.3%) patients had a post-treatment pregnancy (HR 2.14, 95% CI 0.66-6.92). No differences in 10-year DFS (72.4% in CT+GnRHa arm vs. 71.2% in CT alone arm: HR 1.16, 95% CI 0.76-1.77) nor in 10-year OS (82.0% in CT+GnRHa arm vs. 85.9% in CT alone arm: HR 1.17, 95% CI 0.67-2.03) were observed. There was no interaction between treatment effect and hormone receptor status. In patients with hormone receptor-positive disease, HR was 1.02 (95% CI 0.63-1.63) for DFS and 1.12 (95% CI 0.59-2.11) for OS. Out of 43 patients tested for BRCA, overall incidence of POI, irrespective of treatment arm, was 20% in mBRCA patients (n = 10) and 12% in patients without mBRCA (n = 33). In mBRCA patients, incidence of POI was 0% and 33% in the CT+GnRHa and CT alone arms, respectively. One post-treatment pregnancy was described in a patient with mBRCA1 in the CT alone arm. Conclusions: The final analysis of the PROMISE-GIM6 trial at a median follow-up of 12.4 years provides reassuring evidence on the safety of GnRHa use during CT as a strategy to preserve ovarian function in premenopausal patients with hormone receptor-positive EBC. Clinical trial information: NCT00311636.


2021 ◽  
Vol 39 (18_suppl) ◽  
pp. LBA2-LBA2
Author(s):  
Rui-hua Xu ◽  
Hai-Qiang Mai ◽  
Qiu-Yan Chen ◽  
Dongping Chen ◽  
Chaosu Hu ◽  
...  

LBA2 Background: Gemcitabine-cisplatin (GP) chemotherapy is the standard 1st line treatment for locally advanced, recurrent or metastatic (r/m) NPC. Toripalimab, a humanized IgG4K monoclonal antibody specific for PD-1, provided durable responses in patients (pts) with r/m NPC as monotherapy in the ≥2nd line setting (POLARIS-02 study). The results of JUPITER-02, a randomized, placebo-controlled, double-blinded Phase III trial of toripalimab in combination with GP chemotherapy as first-line treatment for r/m NPC are summarized. Methods: Pts with advanced NPC with no prior chemotherapy in the r/m setting were randomized (1:1) to receive toripalimab 240 mg or placebo d1 in combination with gemcitabine 1000 mg/m2 d1, d8 and cisplatin 80 mg/m2 d1 every 3 weeks (Q3W) for up to 6 cycles, followed by monotherapy with toripalimab or placebo Q3W until disease progression, intolerable toxicity, or completion of 2 years of treatment. Stratification factors were ECOG PS (0 vs. 1) and extent of disease (recurrent vs. primary metastatic) at enrollment. Progression-free survival (PFS) and response were assessed by independent review committee (IRC) per RECIST v1.1. The primary endpoint was PFS by IRC in the ITT population. Secondary end points included ORR, DOR and OS. There was one prespecified interim analysis of PFS at 130 PFS events with a planned final analysis at 200 PFS events. Results: 289 pts were randomized: 146 to the toripalimab arm and 143 to the placebo arm. By May 30, 2020 as the interim analysis cutoff date, the median treatment duration was 39 weeks in the toripalimab arm and 36 weeks in the placebo arm. A significant improvement in PFS was detected for the toripalimab arm compared to the placebo arm (HR = 0.52 [95% CI: 0.36-0.74] two-sided p = 0.0003), with median PFS of 11.7 vs. 8.0 months. The 1-year PFS rates were 49% and 28% respectively. An improvement in PFS was observed across relevant subgroups, including all PD-L1 subgroups. The ORR was 77.4% vs. 66.4% (P = 0.033) and the median DOR was 10.0 vs. 5.7 months (HR = 0.50 [95% CI: 0.33-0.78]). As of Jan 15, 2021, OS was not mature, with 25 deaths in the toripalimab arm and 35 in the placebo arm (HR = 0.68 [95% CI: 0.41-1.14], P = 0.14). The incidence of Grade ≥3 adverse events (AEs) (89.0% vs 89.5%); AEs leading to discontinuation of toripalimab/placebo (7.5% vs 4.9%); and fatal AEs (2.7% vs 2.8%) were similar between two arms; however, immune-related (irAEs) (39.7% vs. 18.9%) and Grade ≥3 irAEs (7.5% vs. 0.7%) were more frequent in the toripalimab arm. Conclusions: The addition of toripalimab to GP chemotherapy as 1st-line treatment for pts with advanced NPC provided superior PFS and ORR and longer DOR than GP alone with a manageable safety profile. These results support the use of toripalimab with GP chemotherapy as the new standard care for this population. Clinical trial information: NCT03581786.


2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 239-239
Author(s):  
Matthew Raymond Smith ◽  
Karim Fizazi ◽  
Teuvo L. J. Tammela ◽  
Felipe Melo Cruz ◽  
Luke T. Nordquist ◽  
...  

239 Background: DARO is a structurally distinct androgen receptor inhibitor (ARI) approved for treating nmCRPC. In ARAMIS, DARO significantly reduced the risk of death by 31% (HR = 0.69; 95% CI: 0.53-0.88; p = 0.003) and prolonged median metastasis-free survival vs placebo (PBO; 40.4 months vs 18.4 months; HR = 0.41; 95% CI: 0.34-0.50; p < 0.001). Adverse events (AEs) of interest commonly associated with ARI therapy, such as fatigue, falls, fractures, rash, mental impairment, and hypertension, as well as interactions between ARIs and concomitantly administered drugs, can impact patient daily life. In the final analysis of the double-blind (DB) period of the ARAMIS trial, DARO had a favorable safety profile, showing ≤2% difference vs PBO for most AEs of interest. Fatigue was the only AE with > 10% incidence with DARO. The incidence of permanent discontinuation due to AEs was also similar between DARO and PBO (8.9% vs 8.7%). Here we present safety data for prolonged treatment with DARO from the final analysis of the DB + open-label (OL) period of ARAMIS. Methods: Patients (pts) with nmCRPC (N = 1509) were randomized 2:1 to DARO or matched PBO while continuing androgen deprivation therapy. The data cut-off for the primary analysis of the DB period was September 3, 2018. Study unblinding occurred on November 30, 2018, after which pts in the DARO arm still receiving study treatment continued with OL DARO. The data cut-off for final analysis of the DB+OL period was November 15, 2019. Results: At the final analysis, the median treatment duration for pts randomized to DARO was 18.5 months for the DB period and 25.8 months for the DB+OL period. At the final cut-off date, 48.8% of patients in the DARO DB+OL group were still receiving DARO treatment. The increase in the incidence of any-grade AEs (85.7% vs 89.8%) and serious AEs (26.1% vs 32.1%) between the DB and DB+OL period was small. Between the DB and DB+OL periods, only minor numerical changes for ARI-associated AEs were observed. When the incidences were corrected for exposure, there were minimal differences between the DB and DB+OL period, e.g., the fracture rate was 3.4 vs 4.0 per 100 patient-years for the DB vs DB+OL periods, respectively. Fatigue was the only ARI-associated AE of interest that exhibited > 10% incidence in the DARO arm during the DB+OL period. The incidence of permanent discontinuation of DARO due to AEs increased slightly from 8.9% during the DB period to 10.5% during the DB+OL period; the incidence of discontinuation of PBO due to AEs during the DB period was 8.7%. Conclusions: With longer treatment exposure, DARO remained well-tolerated. In the DB+OL period, no new safety signals were observed. The expected increases in incidence of AEs between the DB and DB+OL periods largely disappeared when adjusted for the longer exposure, confirming the favorable safety profile of DARO with prolonged treatment. Clinical trial information: NCT02200614.


2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 240-240
Author(s):  
Neal D. Shore ◽  
Karim Fizazi ◽  
Teuvo Tammela ◽  
Murilo Luz ◽  
Manuel Philco Salas ◽  
...  

240 Background: DARO is a structurally distinct androgen receptor inhibitor approved for the treatment of non-metastatic castration-resistant prostate cancer (nmCRPC) based on significantly prolonged metastasis-free survival compared with PBO (median 40.4 vs 18.4 months; hazard ratio [HR] 0.41; 95% confidence interval [CI] 0.34–0.50; P < 0.0001) and a favorable safety profile in the phase III ARAMIS trial. Following unblinding at the primary analysis, crossover from PBO to DARO was permitted for the subsequent open-label treatment phase. Sensitivity analyses were performed to assess the effect of PBO–DARO crossover on OS benefit. Methods: Patients (pts) with nmCRPC receiving androgen deprivation therapy were randomized 2:1 to DARO (n = 955) or PBO (n = 554). In addition to OS, secondary endpoints included times to pain progression, first cytotoxic chemotherapy, first symptomatic skeletal event, and safety. The OS analysis was planned to occur after approximately 240 deaths, and secondary endpoints were evaluated in a hierarchical order. Iterative parameter estimation (IPE) and rank-preserving structural failure time (RPSFT) analyses were performed as pre-planned sensitivity analyses to adjust for the treatment effect of PBO–DARO crossover. The IPE method used a parametric model for the survival times and iteratively determined the model parameter describing the magnitude of the treatment effect, whereas a grid search and non-parametric log-rank test were used for the RPSFT analysis. The IPE and RPSFT analyses both generated a Kaplan–Meier curve for the PBO arm that predicts what would have been observed in the absence of PBO–DARO crossover. Results: After unblinding, 170 pts (30.7% of those randomized to PBO) crossed over from PBO to DARO; median treatment duration from unblinding to the final data cut-off was 11 months. Final analysis of the combined double-blind and open label periods was conducted after 254 deaths (15.5% of DARO and 19.1% of PBO pts) and showed a statistically significant OS benefit for DARO vs PBO (HR 0.69; 95% CI 0.53–0.88; P = 0.003). Results from the IPE (HR 0.66; 95% CI 0.51–0.84; P < 0.001) and RPSFT (HR 0.68; 95% CI 0.51–0.90; P = 0.007) analyses were similar to those from the intention-to-treat population, showing that the impact of PBO–DARO crossover was small. Additional analyses accounting for the effect of PBO–DARO crossover will be presented. The safety profile of DARO continued to be favorable at the final analysis, and discontinuation rates at the end of the double-blind period remained unchanged from the primary analysis (8.9% with DARO and 8.7% with PBO). Conclusions: Early treatment with DARO in men with nmCRPC is associated with significant improvement in OS regardless of pts crossing over from PBO to DARO. The safety profile of DARO remained favorable at the final analysis. Clinical trial information: NCT02200614.


2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 302-302
Author(s):  
Yoshihiko Tomita ◽  
Robert J. Motzer ◽  
Toni K. Choueiri ◽  
Brian I. Rini ◽  
Hideaki Miyake ◽  
...  

302 Background: In the phase III JAVELIN Renal 101 trial (NCT02684006), A + Ax demonstrated progression-free survival (PFS) and objective response rate (ORR) benefit across IMDC risk groups (favorable, intermediate, and poor) vs S in patients with previously untreated aRCC. Here we report efficacy of A + Ax vs S by number of IMDC risk factors (0, 1, 2, 3, and 4-6) and target tumor sites (1, 2, 3, and ≥4) at baseline from the second interim analysis of overall survival (OS). Methods: Patients were randomized 1:1 to receive A 10 mg/kg intravenously every 2 wk + Ax 5 mg orally twice daily or S 50 mg orally once daily for 4 wk (6-wk cycle). PFS and ORR per independent central review (RECIST 1.1) and OS were assessed. Results: At data cut-off (Jan 2019), median (m) follow-up for OS and PFS was 19.3 vs 19.2 mo and 16.8 vs 15.2 mo for the A + Ax vs S arm, respectively. The table shows OS, PFS, and ORR by number of IMDC risk factors and target tumor sites at baseline. A + Ax generally demonstrated efficacy benefit vs S across subgroups. Conclusions: With extended follow-up, A + Ax generally demonstrated efficacy benefit vs S across the number of IMDC risk factors and tumor sites at baseline in aRCC. OS was still immature; follow-up for the final analysis is ongoing. Clinical trial information: NCT02684006 . [Table: see text]


2020 ◽  
Vol 158 (6) ◽  
pp. S-1192-S-1193
Author(s):  
Stephen B. Hanauer ◽  
Stefan Schreiber ◽  
Sigrid E. Balser ◽  
Ekkehard Brockstedt ◽  
Viktoria Moschetti ◽  
...  

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