Practical implementation of a modified continual reassessment method for dose-finding trials

1998 ◽  
Vol 41 (6) ◽  
pp. 429-436 ◽  
Author(s):  
S. Piantadosi ◽  
J. D. Fisher ◽  
S. Grossman
Keyword(s):  
Dose Finding ◽  
Practical Implementation ◽  
Continual Reassessment Method ◽  
Continual Reassessment

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]

Optimization of Fludarabine + Melphalan Conditioning for Marrow Transplantation From Unrelated Donors for Patients with Hematopoietic Malignancies: A Prospective Dose-Finding Trial Using Modified Continual Reassessment Method.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2273-2273
Author(s):  
Seitaro Terakura ◽  
Masashi Sawa ◽  
Haruhiko Ohashi ◽  
Tomonori Kato ◽  
Satoshi Nishiwaki ◽  
...  
Keyword(s):  
Phase I ◽  
Graft Failure ◽  
Dose Finding ◽  
Continual Reassessment Method ◽  
Donor Chimerism ◽  
Continual Reassessment ◽  
Level 3 ◽  
Unrelated Donors ◽  
Level 1 ◽  
Level 2

Abstract Abstract 2273 Poster Board II-250 Background Development of reduced intensity conditioning (RIC) regimen has enabled older patients, who are not expected to tolerate the toxicity of myeloablative conditioning, to be treated with allogeneic HSCT. Because the risk of rejection after BMT is substantially higher than that of PBSCT in RIC transplantation, PBSC is commonly used for RIC transplantation. However, PBSCT from unrelated donors is not currently available in Japan. Therefore, a better dosage of conditioning to ensure engraftment in RIC with BM is needed. Here, we selected the fludarabine plus melphalan regimen which has sufficient potential to induce marrow engraftment if melphalan at 180mg/m2 is used, and planned further optimization of melphalan dosage. The rationale for modulating the dose of melphalan resulted from accumulated observations that melphalan is associated with toxicities, while fludarabine is not. Because the optimal dose of melphalan to minimize regimen-related toxicities and to enable sustained engraftment remains unknown to date, we investigated the recommended dose of melphalan in a phase I study. Patients and Methods To adjust the melphalan dose, we adopted a modified continual reassessment method (CRM) which has been hypothesized to allow a faster and more accurate dose reduction/escalation in patients needed to reach the recommended dose compared with classical algorithmic dose modification design. The conditioning regimen consisted of 125 mg/m2 intravenous fludarabine (day-6∼-2) in combination with the examination dose of intravenous melphalan (day-3, -2). Because the use of fludarabine at 125mg/m2 and melphalan at 180mg/m2 was known to induce reliable engraftment, we set the first dose level to receive 160mg/m2 of melphalan. The primary endpoint was an achievement of donor-type T-cell chimerism at day 28 with successful engraftment defined as 90% or more donor cells. Five patients were planned to be accrued for each dose level and chimerism data was used to determine the next dose. A maximum dose reduction of melphalan for the next level was limited to 30mg/m2 to avoid the potential risk of graft-failure. GVHD prophylaxis consisted of short term methotrexate and tacrolimus. The eligibility criteria were 1) patients with hematological malignancies, who have had more than 3 course of chemotherapy, 2) age, 55 to 65 years, or 40 to 54 years with substantial comorbidity (HCT-CI of 1 or more), 3) no prior stem cell transplantation. The protocol was approved by the Institutional Review Board of each institution. All patients and donors provided written informed consent. Results Seventeen patients were enrolled at doses between 130mg/m2 and 160mg/m2, including one protocol violation and one early death (brain hemorrhage). Both were unavailable for assessment according to the study definition in advance. Of the 15 evaluable patients (9 male, 6 female), the median age was 58 years old (range: 45-63), and their diagnosis were 10 AML, 2 NHL, 1 CML 1 ALL and 1 plasmacytoma. The dose was reduced from 160mg/m2 (level-1) to 130mg/m2 (level-2) after 5 consecutive full donor chimerism (all were 100% at day 28) were observed in level-1. In the level-2, we observed four patients with 100% chimera, and one with 0% chimera at day 28, which eventually resulted in graft-failure. Following the calculation by CRM from level-2, the examination dose was increased to 135mg/m2 (level-3). In the level-3, 5 consecutive full donor chimerism (four 100% and one 90.4%) were observed again. Because the next examination dose was calculated as within 5mg/m2 from the level-3 (135mg/m2), the study was complete as projected. We could not detect any significant difference among the dose levels in terms of toxicity, relapse rate or survival. Discussion Successful dose finding using modified CRM was accomplished. The strategy using engraftment as a primary endpoint instead of toxicity promotes a better chance to determine the optimal dosage compared with the classical phase I trial design with modified Fibonacci method. Our findings demonstrated the melphalan dose of 135mg/m2 in combination with fludarabine is able to induce initial full donor chimerism after unrelated donor BMT and is recommended for further phase II evaluation. Disclosures: No relevant conflicts of interest to declare.

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