Maximum Tolerated Dose of Nalmefene in Patients Receiving Epidural Fentanyl and Dilute Bupivacaine for Postoperative Analgesia

2000 ◽  
Vol 92 (4) ◽  
pp. 1010-1016 ◽  
Author(s):  
Thomas B. Dougherty ◽  
Vivian H. Porche ◽  
Peter F. Thall
Keyword(s):  
Maximum Tolerated Dose ◽  
Dose Finding ◽  
Epidural Fentanyl ◽  
Opioid Antagonist ◽  
Operating Characteristics ◽  
Continual Reassessment Method ◽  
Statistical Tool ◽  
Anesthetic Agents ◽  
Continual Reassessment ◽  
Postanesthetic Care Unit

Background This study investigated the ability of the modified continual reassessment method (MCRM) to determine the maximum tolerated dose of the opioid antagonist nalmefene, which does not reverse analgesia in an acceptable number of postoperative patients receiving epidural fentanyl in 0.075% bupivacaine. Methods In the postanesthetic care unit, patients received a single intravenous dose of 0.25, 0.50, 0.75, or 1.00 microg/kg nalmefene. Reversal of analgesia was defined as an increase in pain score of two or more integers above baseline on a visual analog scale from 0 through 10 after nalmefene administration. Patients were treated in cohorts of one, starting with the lowest dose. The maximum tolerated dose of nalmefene was defined as that dose, among the four studied, with a final mean probability of reversal of anesthesia (PROA) closest to 0.20 (ie., a 20% chance of causing reversal). The modified continual reassessment method is an iterative Bayesian statistical procedure that, in this study, selected the dose for each successive cohort as that having a mean PROA closest to the preselected target PROA of 0.20. Results The modified continual reassessment method repeatedly updated the PROA of each dose level as successive patients were observed for presence or absence of ROA. After 25 patients, the maximum tolerated dose of nalmefene was selected as 0.50 microg/kg (final mean PROA = 0.18). The 1.00-microg/kg dose was never tried because its projected PROA was far above 0.20. Conclusions The modified continual reassessment method facilitated determination of the maximum tolerated dose ofnalmefene . Operating characteristics of the modified continual reassessment method suggest it may be an effective statistical tool for dose-finding in trials of selected analgesic or anesthetic agents.

scholarly journals A Bayesian dose-finding design for outcomes evaluated with uncertainty

2021 ◽  
pp. 174077452110015
Author(s):  
Matthew J Schipper ◽  
Ying Yuan ◽  
Jeremy MG Taylor ◽  
Randall K Ten Haken ◽  
Christina Tsien ◽  
...  
Keyword(s):  
Phase I ◽  
Phase I Trial ◽  
Data Augmentation ◽  
Maximum Tolerated Dose ◽  
Dose Finding ◽  
Continual Reassessment Method ◽  
Number Of Patients ◽  
Continual Reassessment ◽  
Partially Observed ◽  
Dose Limiting Toxicity

Introduction: In some phase I trial settings, there is uncertainty in assessing whether a given patient meets the criteria for dose-limiting toxicity. Methods: We present a design which accommodates dose-limiting toxicity outcomes that are assessed with uncertainty for some patients. Our approach could be utilized in many available phase I trial designs, but we focus on the continual reassessment method due to its popularity. We assume that for some patients, instead of the usual binary dose-limiting toxicity outcome, we observe a physician-assessed probability of dose-limiting toxicity specific to a given patient. Data augmentation is used to estimate the posterior probabilities of dose-limiting toxicity at each dose level based on both the fully observed and partially observed patient outcomes. A simulation study is used to assess the performance of the design relative to using the continual reassessment method on the true dose-limiting toxicity outcomes (available in simulation setting only) and relative to simple thresholding approaches. Results: Among the designs utilizing the partially observed outcomes, our proposed design has the best overall performance in terms of probability of selecting correct maximum tolerated dose and number of patients treated at the maximum tolerated dose. Conclusion: Incorporating uncertainty in dose-limiting toxicity assessment can improve the performance of the continual reassessment method design.

scholarly journals Would the Recommended Dose Have Been Different Using Novel Dose-Finding Designs? Comparing Dose-Finding Designs in Published Trials

2021 ◽  
pp. 1024-1034
Author(s):  
Rebecca B. Silva ◽  
Christina Yap ◽  
Richard Carvajal ◽  
Shing M. Lee
Keyword(s):  
Maximum Tolerated Dose ◽  
Dose Finding ◽  
Simulation Studies ◽  
Toxicity Data ◽  
Continual Reassessment Method ◽  
Optimal Interval ◽  
Patient Allocation ◽  
Continual Reassessment ◽  
Continuous Use ◽  
Dose Levels

PURPOSE Simulation studies have shown that novel designs such as the continual reassessment method and the Bayesian optimal interval (BOIN) design outperform the 3 + 3 design by recommending the maximum tolerated dose (MTD) more often, using less patients, and allotting more patients to the MTD. However, it is not clear whether these novel designs would have yielded different results in the context of real-world dose-finding trials. This is a commonly mentioned reason for the continuous use of 3 + 3 designs for oncology trials, with investigators considering simulation studies not sufficiently convincing to warrant the additional design complexity of novel designs. METHODS We randomly sampled 60 published dose-finding trials to obtain 22 that used the 3 + 3 design, identified an MTD, published toxicity data, and had more than two dose levels. We compared the published MTD with the estimated MTD using the continual reassessment method and BOIN using target toxicity rates of 25% and 30% and toxicity data from the trial. Moreover, we compared patient allocation and sample size assuming that these novel designs had been implemented. RESULTS Model-based designs chose dose levels higher than the published MTD in about 40% of the trials, with estimated and observed toxicity rates closer to the target toxicity rates of 25% and 30%. They also assigned less patients to suboptimal doses and permitted faster dose escalation. CONCLUSION This study using published dose-finding trials shows that novel designs would recommend different MTDs and confirms the advantages of these designs compared with the 3 + 3 design, which were demonstrated by simulation studies.

A prospective PGx and PK/PD dose-finding study of irinotecan based on UGT1A1*6 and *28 genotyping (UGT0601)

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e14560-e14560
Author(s):  
T. Esaki ◽  
T. Satoh ◽  
T. Ura ◽  
T. Tsujinaka ◽  
Y. Sasaki ◽  
...  
Keyword(s):  
Initial Dosage ◽  
Maximum Tolerated Dose ◽  
Dose Finding ◽  
Hematological Toxicity ◽  
Continual Reassessment Method ◽  
Continual Reassessment ◽  
Finding Study ◽  
Dose Finding Study ◽  
Grade 3 ◽  
Dose Limiting Toxicity

e14560 Background: UGT1A1*6 as well as UGT1A1*28 polymorphisms is associated with decreased glucuronidation of SN-38, the active metabolite of irinotecan (CPT-11). Although the maximum tolerated dose (MTD) and the recommended dose (RD) in Hetero was determined 150 mg/m2 (approval dose in Japan), those of Homo were unknown. Methods: Pts received prior chemotherapies except for CPT-11 for metastatic gastrointestinal cancer were enrolled. UGT1A1 polymorphisms were categorized into Wild(*1/*1), Hetero(*1/*28, *1/*6), and Homo(*28/*28, *6/*6, *28/*6). CPT-11 was administered biweekly. Starting doses were 150 mg/m2 in Wild, 100 mg/m2 in Hetero, and 75 mg/m2 in Homo. DLT was defined as grade 4 hematological, or grade 3 non-hematological toxicity. MTD closest to dose-limiting toxicity (DLT) appearance of 30% was guided by the continual reassessment method in the cohort of Hetero and Homo. DLT and pharmacokinetic (PK) sampling was evaluated during the 1st cycle. Results: Eighty-two pts were enrolled from November 2006 to November 2008 (Wild, Hetero, Homo: 41, 20, and 21, respectively). The dose level reached at 150 mg/m2 in Homo. At 150 mg/m2, DLT was observed in six pts of Homo (grade 4 neutropenia, grade 3 diarrhea: 6 and 1, respectively). The probability of DLTs were 22.2% at 125 mg/m2, and 37.4% at 150 mg/m2. The MTD was determined 150 mg/m2 in pts with Homo group. However, the incidences of grade 3/4 neutropenia at 150 mg/m2 during the 1st cycle were 9.8% (4/41), 18.8% (3/16), and 62.5% (10/16) in Wild, Hetero, and Homo, respectively. And the second administration was delayed 7 days or more in most pts in Homo (63% at 150 mg/m2). In one pt of Homo for *28/*28 died of septic shock during the 2nd cycle. SN-38 AUC (0–24h, ng*hr/mL, median) was 239 in Wild, 237 in Hetero, and 410 in Homo. Pts with Homo showed the different trend of PK/PD compared to those with Wild and Hetero. Conclusions: The MTD was 150 mg/m2 in pts with Homo group and the most frequent DLT was grade 4 neutropenia. However, our findings suggest that 150 mg/m2 q2w is difficult to recommend and the initial dosage and administration should be considered carefully for pts with Homo. [Table: see text]

scholarly journals A comparison between the continual reassessment method and D-optimum design for dose finding in phase I clinical trials

2016 ◽  
Vol 53 (2) ◽  
pp. 69-82
Author(s):  
M. Iftakhar Alam
Keyword(s):  
Clinical Trials ◽  
Phase I ◽  
Optimum Design ◽  
Maximum Tolerated Dose ◽  
Dose Finding ◽  
Parameter Estimates ◽  
Phase I Clinical Trials ◽  
Continual Reassessment Method ◽  
Continual Reassessment ◽  
Asymptotic Variability

AbstractThe continual reassessment method is a model-based procedure, described in the literature, used to determine the maximum tolerated dose in phase I clinical trials. The maximum tolerated dose can also be found under the framework of D-optimum design, where information is gathered in such a way so that asymptotic variability in the parameter estimates in minimised. This paper investigates the two methods under some realistic settings to explore any potential differences between them. Simulation studies for six plausible dose-response scenarios show that D-optimum design can work well in comparison with the continual reassessment method in many cases. The D-optimum design is also found to allocate doses from the extremes of the design region to the patients in a trial.

Designing Dose-Escalation Trials With Late-Onset Toxicities Using the Time-to-Event Continual Reassessment Method

2006 ◽  
Vol 24 (27) ◽  
pp. 4426-4433 ◽  
Author(s):  
Daniel Normolle ◽  
Theodore Lawrence
Keyword(s):  
Phase I ◽  
Dose Escalation ◽  
Late Onset ◽  
Maximum Tolerated Dose ◽  
Phase I Trials ◽  
Operating Characteristics ◽  
Time To Event ◽  
Continual Reassessment Method ◽  
Standard Design ◽  
Continual Reassessment

Purpose The standard design for phase I trials of combined chemotherapy and radiation, which enters either three or six patients per dose level, has little statistical basis and is subject to opening and closing because of delayed toxicities that disrupt patient accrual. We compared the operating characteristics of this standard design and the time-to-event continual reassessment method (TITE-CRM) for dose-escalation trials of combination chemotherapy and radiation. Methods The operating characteristics were determined by Monte Carlo simulation of 60,000 phase I trials. Results Compared with the standard trial design, in studies with delayed toxicity (ie, where four or more patients are expected to enter onto the study during a single previously enrolled patient's observation for toxicity), TITE-CRM trials are significantly shorter when toxicity observation times are long, treat more patients at or above the maximum-tolerated dose, identify the maximum-tolerated dose (MTD) more accurately, and provide phase II information, but do not expose patients to significant additional risk. Estimation precision and overdose control of TITE-CRM increase as the design assumptions more closely resemble the true state of nature, but are reduced if, for instance, the toxicity of treatment has been grossly underestimated. Conclusion Compared with the standard design, if there is any prior knowledge concerning the toxicity profile of a treatment, TITE-CRM can leverage it to produce more accurate estimates of the MTD and does not expose patients to significant excess risk, but requires timely communication between clinical investigators, data managers, and study statisticians.

scholarly journals Shift models for dose-finding in partially ordered groups

2018 ◽  
Vol 16 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Bethany Jablonski Horton ◽  
Nolan A Wages ◽  
Mark R Conaway
Keyword(s):  
Maximum Tolerated Dose ◽  
Dose Finding ◽  
Dose Selection ◽  
Continual Reassessment Method ◽  
Two Stage ◽  
Partially Ordered ◽  
Ordered Groups ◽  
Continual Reassessment ◽  
Meaningful Group ◽  
Shift Model

Background Limited options are available for dose-finding clinical trials requiring group-specific dose selection. While conducting parallel trials for groups is an accessible approach to group-specific dose selection, this approach allows for maximum tolerated dose selection that does not align with clinically meaningful group order information. Methods The two-stage continual reassessment method is developed for dose-finding in studies involving three or more groups where group frailty order is known between some but not all groups, creating a partial order. This is an extension of the existing continual reassessment method shift model for two ordered groups. This method allows for dose selection by group, where maximum tolerated dose selection follows the known frailty order among groups. For example, if a group is known to be the most frail, the recommended maximum tolerated dose for this group should not exceed the maximum tolerated dose recommended for any other group. Results With limited alternatives for dose-finding in partially ordered groups, this method is compared to two alternatives: (1) an existing method for dose-finding in partially ordered groups which is less computationally accessible and (2) independent trials for each group using the two-stage continual reassessment method. Simulation studies show that when ignoring information on group frailty, using independent continual reassessment method trials by group, 30% of simulations would result in maximum tolerated dose selection that is out of order between groups. In addition, the two-stage continual reassessment method for partially ordered groups selects the maximum tolerated dose more often and assigns more patients to the maximum tolerated dose compared to using independent continual reassessment method trials within each group. Simulation results for the proposed method and the less computationally accessible approach are similar. Conclusion The proposed continual reassessment method for partially ordered groups ensures appropriate maximum tolerated dose order and improves accuracy of maximum tolerated dose selection, while allowing for trial implementation that is computationally accessible.

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