scholarly journals Impact of Informative Censoring on the Kaplan-Meier Estimate of Progression-Free Survival in Phase II Clinical Trials

2014 ◽  
Vol 32 (27) ◽  
pp. 3068-3074 ◽  
Author(s):  
Federico Campigotto ◽  
Edie Weller
Keyword(s):  
Treatment Failure ◽  
Phase Ii ◽  
Progression Free Survival ◽  
Informative Censoring ◽  
Phase Iii ◽  
Inadequate Response ◽  
Phase Ii Trials ◽  
Free Survival ◽  
Kaplan Meier ◽  
The Impact

Informative censoring in a progression-free survival (PFS) analysis arises when patients are censored for initiation of an effective anticancer treatment before the protocol-defined progression, and these patients are at a different risk for treatment failure than those who continue on therapy. This may cause bias in the estimated PFS when using the Kaplan-Meier method for analysis. Although there are several articles that discuss this issue from a theoretical perspective or in randomized phase III studies, there are little data to demonstrate the magnitude of the bias on the estimated quantities from a phase II trial. This article describes the issues by using two oncology phase II trials as examples, evaluates the impact of the bias using simulations, and provides recommendations. The two trials were selected because they demonstrate two different reasons for censoring. Simulations show that the magnitude of the bias depends primarily on the proportion of patients who are informatively censored and secondarily on the hazard ratio between the group of patients who remain on study and the group of patients who are informatively censored. Recommendations include using an alternative end point, which includes inadequate response and initial signs of clinical progression as treatment failure, and a competing risk analysis for studies in which competing events preclude or modify the probability of observing the primary event of interest. If informative censoring cannot be avoided, then all patients should be observed until progression, and sensitivity analyses should be used as appropriate.

Outcome of patients with recurrent/refractory osteosarcoma enrolled in three recent phase II trials: A report from the Children’s Oncology Group.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 11530-11530
Author(s):  
Seema Rao ◽  
Ruxu Han ◽  
Mark D. Krailo ◽  
Allen Buxton ◽  
Pooja Hingorani ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Phase Ii ◽  
Primary Endpoint ◽  
Progression Free Survival ◽  
Oncology Group ◽  
Phase Ii Trials ◽  
Free Survival ◽  
Significant Difference ◽  
Measurable Disease ◽  
The Impact

11530 Background: Based on seven prior Phase 2 Children’s Oncology Group (COG) trials, the 4-month event-free survival(EFS) and associated confidence interval for relapsed osteosarcoma with measurable disease according to RECIST was determined to be 12% (95% CI 6 - 19%). Three prospective clinical trials were conducted using this historical benchmark to detect activity defined by an EFS improvement of double the upper confidence interval. This report summarizes the outcome of these studies, describes whether the historical data remains an accurate baseline, and considers implications for future phase II trial study design in relapsed osteosarcoma measurable according to RECIST. Methods: We conducted an analysis of outcome for patients with recurrent/refractory osteosarcoma enrolled in three recent prospective COG phase II trials; AOST1321 (unresected cohort), AOST1322 and AOST1521 that used EFS at 4 months as the primary endpoint. Patients were eligible if they had osteosarcoma that had recurred or become refractory after standard therapy and had measurable disease according to RECIST. We assessed whether risk of an EFS event is modified by age, sex, race/ethnicity, number of prior chemotherapy regimens, or time to first relapse. Results: In each of the three phase II trials (unresected group of AOST1321, AOST1322, AOST1521), the drugs tested (denosumab, eribulin and glembatumumab) were concluded to be not effective due to a failure of the patient populations to meet the prespecified active 4-month progression free survival endpoint. The 4-month EFS for the 57 evaluable patients enrolled on these trials was 7% (95% CI 2 – 16%), similar to the 4-month EFS for 96 patients in the previous seven phase II trials of 12% (95% CI 6 - 19%). The combined EFS at 4 months for all 10 studies is 10% (95% CI 6 – 15%).There was no significant difference in EFS across trials based on age, sex, ethnicity, number of prior treatment regimens, consistent with prior analysis. Data from AOST1321 and AOST1521 were analyzed to determine the impact of time to first recurrence on EFS. Two different quantifications were applied: 1 year or less versus 2 or more years; and 2 years or less versus 3 years or more. Neither categorization was statistically significant. Conclusions: The EFS at 4 months in the three new phase II trials is similar to the previous seven phase II single arm trials. The combined analysis of 153 patients from 10 trials tightens the confidence interval, moving the upper 95% CI to 15%. Modification to future study designs could be considered based on this updated analysis. EFS at 4 months remains a robust primary endpoint. Single-arm trials using this endpoint based on the historical benchmark have accrued rapidly and allowed assessment of multiple novel agents in osteosarcoma. The negative trial results and continued poor outcome highlight the need for new approaches for relapsed osteosarcoma. Clinical trial information: NCT02097238, NCT02470091, NCT02487979.

Progression-Free Survival Rate As Primary End Point for Phase II Cancer Clinical Trials: Application to Mesothelioma—The EORTC Lung Cancer Group

2006 ◽  
Vol 24 (19) ◽  
pp. 3007-3012 ◽  
Author(s):  
Julie Francart ◽  
Catherine Legrand ◽  
Richard Sylvester ◽  
Martine Van Glabbeke ◽  
Jan P. van Meerbeeck ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Survival Rate ◽  
Phase Ii ◽  
Progression Free Survival ◽  
New Drugs ◽  
Phase Iii ◽  
Cancer Clinical Trials ◽  
Phase Ii Trials ◽  
Free Survival ◽  
End Point

Purpose Phase II cancer clinical trials play a key role in the development of new drugs. These trials should be designed to accurately determine if the drug should be abandoned or if it is sufficiently promising for further investigation in phase III trials. With new cytostatic agents or when the response assessment is difficult, using the progression-free survival rate (PFSR) at a fixed time point, such as 3, 4, 5, or 6 months, instead of the response rate (RR) as the primary end point is an alternative approach. To design future phase II trials, reference values for PFSRs that correspond to drugs with insufficient (P0) and sufficient (P1) clinical activity (CA) are necessary. This article provides these values in mesothelioma. Materials and Methods The European Organisation for Research and Treatment of Cancer database registered ten closed mesothelioma trials (nine phase II trials and one phase III trial) with 523 total patients. Trials were grouped into three categories according to the published RR: significant (n = 259), moderate (n = 142), and insufficient (n = 122) CA. Results The PFSRs at 3, 4, 5, and 6 months, respectively, were as follows: 72%, 67%, 51%, and 43% in the group with significant CA; 59%, 51%, 42%, and 35% with moderate CA; and 52%, 40%, 34%, and 28% with insufficient CA. Conclusion These values may be used to define relevant P0 and P1 values in future phase II mesothelioma trials that use PFSR as the primary end point.

scholarly journals Anti-Angiogenic Agents in Management of Sarcoma Patients: Overview of Published Trials

2020 ◽  
Vol 10 ◽  
Author(s):  
Pierre-Yves Cren ◽  
Loïc Lebellec ◽  
Thomas Ryckewaert ◽  
Nicolas Penel
Keyword(s):  
Soft Tissue ◽  
Soft Tissue Sarcoma ◽  
Phase Ii ◽  
Progression Free Survival ◽  
Phase Iii ◽  
Phase Ii Trials ◽  
Double Blind ◽  
Multikinase Inhibitors ◽  
Randomized Phase Ii ◽  
Phase Iii Trials

We reviewed all fully published clinical trials assessing anti-angiogenic agents in sarcoma patients (last issue, January 13, 2020). Anti-angiogenic macromolecules (e.g., bevacizumab or ombrabulin) provide disappointing results. Many multikinase inhibitors have been assessed with non-randomized phase II trials with limited samples and without stratification according to histological subtypes, therefore interpretation of such trials is very challenging. On the contrary, pazopanib, regorafenib, and sorafenib have been assessed using double-blind placebo-controlled randomized phase II or phase III trials. Compared to placebo, sorafenib demonstrates activity in desmoid-type fibromatosis patients. Based on results of phase 3 trial, pazopanib had obtained approval for treatment of pretreated non-adipocytic soft tissue sarcoma. Regorafenib is currently assessed in several clinical settings and provides significant improvement of progression-free survival in pre-treated non-adipocytic soft tissue sarcoma and in advanced pretreated osteosarcoma. Multikinase inhibitors are a breakthrough in sarcoma management. Many trials are ongoing. Nevertheless, predictive factors are still missing.

scholarly journals Phase III Study Comparing Gemcitabine Plus Cetuximab Versus Gemcitabine in Patients With Advanced Pancreatic Adenocarcinoma: Southwest Oncology Group–Directed Intergroup Trial S0205

2010 ◽  
Vol 28 (22) ◽  
pp. 3605-3610 ◽  
Author(s):  
Philip A. Philip ◽  
Jacqueline Benedetti ◽  
Christopher L. Corless ◽  
Ralph Wong ◽  
Eileen M. O'Reilly ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Treatment Failure ◽  
Survival Time ◽  
Pancreatic Adenocarcinoma ◽  
Pancreas Cancer ◽  
Progression Free Survival ◽  
Phase Iii ◽  
Free Survival ◽  
Time To Treatment ◽  
Time To Treatment Failure

Purpose Patients with advanced pancreas cancer present with disease that is poorly responsive to conventional therapies. Preclinical and early clinical evidence has supported targeting the epidermal growth factor receptor (EGFR) signaling pathway in patients with pancreas cancer. This trial was conducted to evaluate the contribution of an EGFR-targeted agent to standard gemcitabine therapy. Cetuximab is a monoclonal antibody against the ligand-binding domain of the receptor. Patients and Methods Patients with unresectable locally advanced or metastatic pancreatic adenocarcinoma were randomly assigned to receive gemcitabine alone or gemcitabine plus cetuximab. The primary end point was overall survival. Secondary end points included progression-free survival, time to treatment failure, objective response, and toxicity. Results A total of 745 eligible patients were accrued. No significant difference was seen between the two arms of the study with respect to the median survival time (6.3 months for the gemcitabine plus cetuximab arm v 5.9 months for the gemcitabine alone arm; hazard ratio = 1.06; 95% CI, 0.91 to 1.23; P = .23, one-sided). Objective responses and progression-free survival were similar in both arms of the study. Although time to treatment failure was longer in patients on gemcitabine plus cetuximab (P = .006), the difference in length of treatment was only 2 weeks longer in the combination arm. Among patients who were studied for tumoral EGFR expression, 90% were positive, with no treatment benefit detected in this patient subset. Conclusion In patients with advanced pancreas cancer, the anti-EGFR monoclonal antibody cetuximab did not improve the outcome compared with patients treated with gemcitabine alone. Alternate targets other than EGFR should be evaluated for new drug development.

scholarly journals Blinded Independent Central Review of Progression-Free Survival in Phase III Clinical Trials: Important Design Element or Unnecessary Expense?

2008 ◽  
Vol 26 (22) ◽  
pp. 3791-3796 ◽  
Author(s):  
Lori E. Dodd ◽  
Edward L. Korn ◽  
Boris Freidlin ◽  
C. Carl Jaffe ◽  
Lawrence V. Rubinstein ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Treatment Effectiveness ◽  
Progression Free Survival ◽  
Informative Censoring ◽  
Phase Iii ◽  
General Strategy ◽  
Design Element ◽  
Free Survival ◽  
Using Data

Progression-free survival is an important end point in advanced disease settings. Blinded independent central review (BICR) of progression in randomized clinical trials has been advocated to control bias that might result from errors in progression assessments. However, although BICR lessens some potential biases, it does not remove all biases from evaluations of treatment effectiveness. In fact, as typically conducted, BICRs may introduce bias because of informative censoring, which results from having to censor unconfirmed locally determined progressions. In this article, we discuss the rationale for BICR and different ways of implementing independent review. We discuss the limitations of these approaches and review published trials that report implementing BICR. We demonstrate the existence of informative censoring using data from a randomized phase II trial. We conclude that double-blinded trials with consistent application of measurement criteria are the best means of ensuring unbiased trial results. When such designs are not practical, BICR is not recommended as a general strategy for reducing bias. However, BICR may be useful as an auditing tool to assess the reliability of marginally positive results.

Four Years of Follow-Up of 1027 Patients with Late Chronic Phase (L-CP), Accelerated Phase (AP), or Blast Crisis (BC) Chronic Myeloid Leukemia (CML) Treated with Imatinib in Three Large Phase II Trials.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 23-23 ◽  
Author(s):  
Richard T. Silver ◽  
Moshe Talpaz ◽  
Charles L. Sawyers ◽  
Brian J. Druker ◽  
Andreas Hochhaus ◽  
...  
Keyword(s):  
Phase Ii ◽  
Chronic Phase ◽  
Progression Free Survival ◽  
Cytogenetic Response ◽  
Imatinib Treatment ◽  
Phase Ii Trials ◽  
Free Survival ◽  
Phase Ii Studies ◽  
Large Phase

Abstract Background This report updates the results of 3 large phase II studies of the orally available BCR-ABL tyrosine kinase inhibitor imatinib for patients (pts) in AP, BC and late chronic phase (L-CP) CML failing prior interferon therapy (Kantarjan et al, ASH 2003; Talpaz et al, ASH 2003). Methods Between August 1999 and June 2000, 1027 pts were enrolled in phase II trials for CML in L-CP (n=532), AP (n=235) or BC (n=260). Pts in L-CP were treated with 400 mg/day and pts in AP or BC with either 400 or 600 mg/day. Dose escalation up to 800 mg/d was allowed in the late-chronic phase study. Pts with a confirmed diagnosis of AP (n=181), BC (n=229) and late-chronic phase (n=454) were evaluated for efficacy. All pts were evaluated for safety. The median time from initial diagnosis to study entry was 32 months for L-CP pts. Results As of 31-Jul-03, 5% patients with BC, 25% of CML-AP and 64% of L-CP patients still remain on treatment. At the recommended dose of 600 mg, an estimated 40% (AP) and 7% (BC) of patients remained progression-free at 36 months, and an estimated 55% (AP) and 14% (BC) patients were alive at 36 months after initiation of imatinib. The 3-year survival rates for pts with AP with a major cytogenetic response at 3 months were 85% vs. 52% for pts with no response (p<0.001). In L-CP patients with a median follow-up of 40 months, 65% of patients achieved a major cytogenetic response, which was complete in 52%. The cytogenetic responses were durable with an estimated 82% of the pts in continuos major cytogenetic response at 3 years. The estimated rates of progression-free survival and overall survival at 3 years were 80% and 88%. Pts with at least a minor cytogenetic response at 6 months ≤65% Ph+ cells) had an estimated 3-year survival rate of 96% vs. 86% for pts with a ( minimal response and 81% for pts with no cytogenetic response (p<0.001). Conclusion In large phase II studies, continuous imatinib treatment is safe and has improved progression-free survival of patients at all stages of CML. Responses to imatinib are durable and are predictive of long-term outcomes. These results will be further updated at the meeting using a data base lock planned for 20-Sept-04 (using data collected up to 31-July-04, i.e. more than 4 years after the last pts enrollment).

Twenty years of chemotherapy for colorectal cancer (CRC): Progress made, insights gleaned.

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 596-596
Author(s):  
Irfan Jawed ◽  
Julia Wilkerson ◽  
Austin G. Duffy ◽  
Antonio Tito Fojo
Keyword(s):  
Supportive Care ◽  
Odds Ratio ◽  
Progression Free Survival ◽  
Phase Iii ◽  
Negative Effects ◽  
Phase Ii Trials ◽  
Free Survival ◽  
Large Phase ◽  
And Control ◽  
Over Time

596 Background: The past 20 years have seen progress in CRC therapy with more effective agents and better medical, surgical and supportive care. Methods: We conducted a systematic review of 101 phase III and large phase II trials in CRC to quantify benefit over time with first-line and subsequent therapies. Outcomes examined in the experimental (EA) and control arms (CA) included progression-free survival (PFS), overall response rate (ORR), stable disease (SD), overall survival (OS) and post-treatment survival (PTS). Data were analyzed according to dates of publication and median enrollment. Results: Significant outcomes are reported; most had R2 values > 0.6. OS of EA improved 0.83 mos/yr. Importantly the OS of CA improved 0.58 mos/yr likely reflecting use of experimental therapies in CA in subsequent studies and improvement in CRC care over time as suggested by: (1) modest improvements of PFS: 0.33 [EA] and 0.26 [CA] mos/yr; (2) PTS gains of 0.48 [EA] and 0.29 [CA] mos/yr, accounting for majority of OS gains; and (3) lack of OS improvement in 14 second/subsequent line trials. Using logistic regression to examine all drugs as class predictors of increasing OS, oxaliplatin [OX], bevacizumab [BEV], and irinotecan [IRI] were significant in the EA, but only OX and BEV were significant in the CA. Capecitabine [CAP] and cetuximab/panitumumab [CET/PAN] were not significant in EA or CA, with CAP odds ratio towards null and CET/PAN odds ratio away from null. The lack of IRI effect in CA concurs with observation that only IRI regimens had worse OS in CA compared with EA. The CET/PAN results likely reflect lack of efficacy/harm in patients with WT KRAS tumors. As expected PFS and PTS correlate highly with OS, but importantly ORR had very high correlations with both PFS and OS. SD emerged as an “adverse” outcome, OS decreasing as SD rates increase. Conclusions: OS of CRC patients has improved gradually over past two decades, with gains from chemotherapy but also other factors, such as lead-time bias, more loco-regional approaches and improved supportive care. IRI performed better in EA than in CA. CET/PAN had negative effects in the entire population. In CRC, ORR correlates highly with OS, while SD portends a poor outcome.

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