scholarly journals Inferences About Drug Safety in Phase III Trials in Oncology: Examples From Advanced Prostate Cancer

Author(s):  
Joshua Z Drago ◽  
Mithat Gönen ◽  
Gita Thanarajasingam ◽  
Chana A Sacks ◽  
Michael J Morris ◽  
...  

Abstract Background Safety is a central consideration when choosing between multiple medications with similar efficacy. We aimed to evaluate whether adverse event (AE) profiles of 3 such drugs in advanced prostate cancer could be distinguished based on published literature. Methods We assessed consistency in AE reporting, AE risk in placebo arms, and methodology used for risk estimates and quantification of statistical uncertainty in randomized placebo-controlled phase III trials of apalutamide, enzalutamide, and darolutamide in advanced prostate cancer. Results Seven included clinical trials enrolled a total of 9215 participants (range = 1051-1715 per trial) across 3 prostate cancer disease states. Within disease states, baseline patient characteristics appeared similar between trials. Of 54 distinct AE types in total, only 3 (fatigue, hypertension, and seizure) were reported by all 7 trials. Absolute risks of AEs in the placebo arms differed systematically and more than twofold between trials, which was associated with visit frequency and resulted in different degrees of uncertainty in AE profiles between trials. No trial used inferential methodology to quantify statistical uncertainty in AE risks, but 6 of 7 trials drew overall conclusions. Two trials concluded that there was no elevated AE risk because of the intervention, including the trial of darolutamide, which had the greatest statistical uncertainty. Conclusions Rigorous comparison of drug safety was precluded by heterogeneity in AE reporting, variation in AE risks in the placebo arms, and lack of inferential statistical methodology, underscoring considerable opportunities to improve how AE data are collected, analyzed, and interpreted in oncology trials.

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 5137-5137
Author(s):  
A. J. Armstrong ◽  
S. Halabi ◽  
I. F. Tannock ◽  
D. J. George ◽  
R. DeWit ◽  
...  

5137 Background: Our aim was to develop and validate clinically applicable predictive factors for a >30% PSA decline 3 months following chemotherapy initiation, and to assess the performance of a risk-group based classification in predicting PSA declines and overall survival (OS) in men receiving chemotherapy for mCRPC. Methods: In TAX327, 1006 men with mCRPC were randomized to receive docetaxel (D) in two schedules, or mitoxantrone (M), each with prednisone: 989 provided data on PSA decline at 3 months. Predictive factors for a >30% 3-month decline in PSA levels were identified using multivariate logistic regression in D treated men (n = 656) and validated in M treated men (n = 333). Risk factors were combined to form risk groups to predict PSA declines, OS, tumor, and pain responses. Prostate Cancer Working Group (PCWG2) disease states were evaluated for these outcomes in docetaxel treated men. Results: In multivariate analysis, four independent risk factors predicted for absence of >30% decline in 3-month PSA: significant baseline pain (OR 0.63 p = 0.02), visceral metastases (OR 0.66, p = 0.03), anemia (hemoglobin <13 g/dl, OR 0.72 p = 0.07), and bone scan progression at baseline (OR 0.60 p = 0.009). Predictive accuracy was moderate with a concordance index (c-index) of 0.61. Risk groups (good, intermediate, poor) were developed with median OS of 25.7 (95% CI 23.3–28.6), 18.7 (17.3–19.7), and 12.8 (11.5–14.6) months, respectively (p < 0.0001), and >30% PSA decline in 78, 66, and 58 percent of men (p < 0.001). In the validation M cohort, similar trends for PSA declines and OS were noted across risk groups (OS 22.5, 16.0, 11.8 mo, p < 0.001). PCWG2 subtypes (node only, bone metastatic, and visceral disease), were also highly prognostic and predictive but did not predict OS as well as the TAX327 risk groups (c-index 0.56). Conclusions: Risk groups have been identified and internally validated that predict PSA decline and OS in men with mCRPC. This classification may facilitate evaluation of new regimens of systemic therapy that warrant definitive testing in comparison to docetaxel and prednisone in phase III trials. Prospective validation of these risk groups is needed. [Table: see text]


2020 ◽  
Vol 16 (2) ◽  
pp. e201-e210 ◽  
Author(s):  
Sarah E. Wong ◽  
Louis Everest ◽  
Di M. Jiang ◽  
Ronak Saluja ◽  
Kelvin K.W. Chan ◽  
...  

PURPOSE: As novel hormonal therapies, such as abiraterone and enzalutamide, move into earlier stages of treatment of advanced prostate cancer, there are significant cost implications. We used the ASCO Value Framework (AVF) and European Society of Medical Oncology (ESMO) Magnitude of Clinical Benefit Scale (MCBS) to quantify and compare the incremental clinical benefit and costs of these agents in the metastatic castration-resistant prostate cancer (mCRPC) and metastatic castration-sensitive prostate cancer (mCSPC) settings. METHODS: We searched PubMed for randomized phase III trials of abiraterone and enzalutamide in mCRPC and mCSPC. Incremental clinical benefit was quantified using the AVF and ESMO-MCBS by 2 independent assessors. Incremental drug costs were calculated using average wholesale prices (AWPs) from the RED BOOK Online. RESULTS: In mCRPC, 2 abiraterone trials (COU-AA-301 and COU-AA-302) and 2 enzalutamide trials (AFFIRM and PREVAIL) met search criteria. AVF scores ranged from 46.3 to 66.6, suggesting clinical benefit; ESMO-MCBS scores ranged from 3 to 5, with lower clinical benefit in the mCRPC predocetaxel setting. The overall incremental AWP ranged from $83,460.94 to $205,128.85. In mCSPC, 4 trials met criteria (LATITUDE, STAMPEDE, ENZAMET, and ARCHES; AVF scores were 79.8, 33.3, 59, and 17, respectively). All of the studies showed benefit except ARCHES. By ESMO-MCBS, both LATITUDE and STAMPEDE showed benefit (score for 4 for both studies); ENZAMET and ARCHES were not evaluable. The overall cost of treatment was significantly higher in the mCSPC setting. CONCLUSION: The AVF and ESMO-MCBS frameworks generated slightly different results but suggested that abiraterone and enzalutamide show clinical benefit in both mCRPC and mCSPC but trended to lower clinical benefit and increased costs in earlier disease stages. Further refinement of the AVF and ESMO-MCBS is needed to facilitate their use and their ability to inform clinical practice in a rapidly changing treatment landscape.


2007 ◽  
Vol 89 (3) ◽  
pp. 207-211 ◽  
Author(s):  
JF Thorpe ◽  
S Jain ◽  
TH Marczylo ◽  
AJ Gescher ◽  
WP Steward ◽  
...  

INTRODUCTION Prostate cancer is an excellent target for chemoprevention strategies; given its late age of onset, any delay in carcinogenesis would lead to a reduction in its incidence. This article reviews all the completed and on-going phase III trials in prostate cancer chemoprevention. PATIENTS AND METHODS All phase III trials of prostate cancer chemoprevention were identified within a Medline search using the keywords ‘clinical trial, prostate cancer, chemoprevention’. RESULTS In 2003, the Prostate Cancer Prevention Trial (PCPT) became the first phase III clinical trial of prostate cancer prevention. This landmark study was terminated early due to the 24.8% reduction of prostate cancer prevalence over a 7-year period in those men taking the 5α-reductase inhibitor, finasteride. This article reviews the PCPT and the interpretation of the excess high-grade prostate cancer (HGPC) cases in the finasteride group. The lack of relationship between cumulative dose and the HGPC cases, and the possible sampling error of biopsies due to gland volume reduction in the finasteride group refutes the suggestion that this is a genuine increase in HGPC cases. The other on-going phase III clinical trials of prostate cancer chemoprevention – the REDUCE study using dutasteride, and the SELECT study using vitamin E and selenium – are also reviewed. CONCLUSIONS At present, finasteride remains the only intervention shown in long-term prospective phase III clinical trials to reduce the incidence of prostate cancer. Until we have the results of trials using alternative agents including the on-going REDUCE and SELECT trials, the advice given to men interested in prostate cancer prevention must include discussion of the results of the PCPT. The increased rate of HGPC in the finasteride group continues to generate debate; however, finasteride may still be suitable for prostate cancer prevention, particularly in men with lower urinary tract symptoms.


2019 ◽  
Vol 20 (11) ◽  
pp. 2676 ◽  
Author(s):  
Zsombor Melegh ◽  
Sebastian Oltean

Prostate cancer is the most commonly diagnosed cancer among men in the Western world. Although localized disease can be effectively treated with established surgical and radiopharmaceutical treatments options, the prognosis of castration-resistant advanced prostate cancer is still disappointing. The objective of this study was to review the role of angiogenesis in prostate cancer and to investigate the effectiveness of anti-angiogenic therapies. A literature search of clinical trials testing the efficacy of anti-angiogenic therapy in prostate cancer was performed using Pubmed. Surrogate markers of angiogenic activity (microvessel density and vascular endothelial growth factor A (VEGF-A) expression) were found to be associated with tumor grade, metastasis, and prognosis. Six randomizedstudies were included in this review: two phase II trials on localized and hormone-sensitive disease (n = 60 and 99 patients) and four phase III trials on castration-resistant refractory disease (n = 873 to 1224 patients). Although the phase II trials showed improved relapse-free survival and stabilisation of the disease, the phase III trials found increased toxicity and no significant improvement in overall survival. Although angiogenesis appears to have an important role in prostate cancer, the results of anti-angiogenic therapy in castration-resistant refractory disease have hitherto been disappointing. There are various possible explanations for this lack of efficacy in castration-resistant refractory disease: redundancy of angiogenic pathways, molecular heterogeneity of the disease, loss of tumor suppressor protein phosphatase and tensin homolog (PTEN) expression as well as various VEGF-A splicing isoforms with pro- and anti-angiogenic activity. A better understanding of the molecular mechanisms of angiogenesis may help to develop effective anti-angiogenic therapy in prostate cancer.


2012 ◽  
Vol 23 ◽  
pp. ix311
Author(s):  
E.J. Small ◽  
J.D. Wesley ◽  
D.I. Quinn ◽  
C. Higano ◽  
D. Lin ◽  
...  

2016 ◽  
Vol 34 (3) ◽  
pp. 280-285 ◽  
Author(s):  
Maha Hussain ◽  
Catherine Tangen ◽  
Celestia Higano ◽  
Nicholas Vogelzang ◽  
Ian Thompson

Purpose Intermittent androgen deprivation (IAD) has been widely tested in prostate cancer. However, phase III trials testing continuous androgen deprivation (CAD) versus IAD have reached inconclusive and seemingly contradictory results. Different design and conduct issues must be critically evaluated to better interpret the results. Patients and Methods Seven published phase III trials were examined for prespecified design and outcomes. Treatment specifications; primary end point; superiority versus noninferiority design assumptions, including magnitude of assumed versus observed noninferiority margin (NIM); duration of follow-up; and quality-of-life (QOL) outcomes were considered in terms of the results and conclusions reported. Results Five trials had a superiority and three had a noninferiority primary hypothesis. Only three trials had a uniform population and overall survival (OS) end point. All trials observed better outcomes in terms of OS and progression-free survival (PFS) than assumed at time of study design, translating into prespecified NIMs or hazard ratios that reflected larger absolute differences in OS or PFS between arms. Lower-than-expected event rates also reduced statistical power for the trials. Other factors, including length of follow-up, cause of death, QOL, and primary end point, and their impact on trial interpretation are discussed. Conclusion No trial to date has demonstrated survival superiority of IAD compared with CAD. Trials concluding IAD is noninferior to CAD were based on wide NIMs that included clinically important survival differences, not likely to be considered comparable by physicians or patients. Interim analyses relying on short follow-up and including a majority of non–prostate cancer deaths will favor a noninferiority conclusion and should be interpreted cautiously. Adequate follow-up is required to ensure capture of prostate cancer deaths in both superiority and noninferiority trials.


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