Generalized multidimensional dynamic allocation method

Minimization in randomized clinical trials

In randomized trials, comparability of the treatment groups is ensured through allocation of treatments using a mechanism that involves some random element, thus controlling for confounding of the treatment effect. Completely random allocation ensures comparability between the treatment groups for all known and unknown prognostic factors. For a specific trial, however, imbalances in prognostic factors among the treatment groups may occur. Although accidental bias can be avoided in the presence of such imbalances by stratifying the analysis, most trialists, regulatory agencies, and other stakeholders prefer a balanced distribution of prognostic factors across the treatment groups. Some procedures attempt to achieve balance in baseline covariates, by stratifying the allocation for these covariates, or by dynamically adapting the allocation using covariate information during the trial (covariate-adaptive procedures). In this Tutorial, the performance of minimization, a popular covariate-adaptive procedure, is compared with two other commonly used procedures, completely random allocation and stratified blocked designs. Using individual patient data of 2 clinical trials (in advanced ovarian cancer and age-related macular degeneration), the procedures are compared in terms of operating characteristics (using asymptotic and randomization tests), predictability of treatment allocation, and achieved balance. Fifty actual trials of various sizes that applied minimization for treatment allocation are used to investigate the achieved balance. Implementation issues of minimization are described. Minimization procedures are useful in all trials but especially when (1) many major prognostic factors are known, (2) many centers of different sizes accrue patients, or (3) the trial sample size is moderate.

Intraperitoneal Carboplatin for Ovarian Cancer - A Phase 2/3 Trial

BACKGROUND: Intraperitoneal chemotherapy has been shown to be effective at reducing mortality for patients with advanced epithelial ovarian cancer but is not widely used in practice. METHODS: We performed the Intraperitoneal Therapy for Ovarian Cancer with Carboplatin (iPocc) trial as an open-label, international, multi-institutional, randomized phase 2/3 clinical trial in women with newly diagnosed epithelial ovarian cancer who underwent laparotomy or laparoscopy. All patients received intravenous paclitaxel (80 mg/m2 on days 1, 8, and 15 of a 21-day cycle). In addition, patients in the control group received intravenous carboplatin (dose-dense intravenous paclitaxel plus intravenous carboplatin [dd-TCiv]), whereas patients in the experimental group received dose-dense intravenous paclitaxel plus intraperitoneal carboplatin (dd-TCip). The primary end point was progression-free survival (PFS). Secondary end points included overall survival, tumor response, treatment completion rate, and incidence of adverse events (AEs). RESULTS: Among 655 patients randomized to treatment, median (95% confidence interval [CI]) PFS was 20.7 (18.1 to 22.8) months for dd-TCiv (n=328) and 23.5 (20.5 to 26.9) months for dd-TCip (n=327; hazard ratio, 0.83; 95% CI, 0.69 to 0.99; P=0.04). The PFS benefit with dd-TCip was consistent in patients with different baseline characteristics, stage, size of residual tumor, age, and performance status. The treatment completion rates were 68.3 and 59.9% in the dd-TCiv and dd-TCip groups, respectively. The incidence of intraperitoneal catheter-related AEs in the dd-TCip group was 10.1%; there were no such AEs in the dd-TCiv group. CONCLUSIONS: In the first-line treatment of advanced epithelial ovarian cancer, intraperitoneal carboplatin resulted in a modest prolongation of PFS when given with dose-dense weekly paclitaxel regardless of residual tumor size, with no impact on noncatheter-related toxicities. (Funded by the Japan Agency for Medical Research and Development, and others; Japan Registry of Clinical Trials number, jRCTs031180141.)

Incorporating covariates information in adaptive clinical trials for precision medicine

Precision medicine is the systematic use of information that pertains to an individual patient to select or optimize that patient's preventative and therapeutic care. Recent studies have classified biomarkers into predictive and prognostic biomarkers based on their roles in clinical studies. To design a clinical trial for precision medicine, predictive biomarkers and prognostic biomarkers should both be included. In statistical analysis, biomarkers are mathematically treated as covariates. We first classify covariates into predictive and prognostic covariates according to their roles. We then provide a brief review of recent advances in adaptive designs that incorporate covariates. However, the literature includes no designs that incorporate both prognostic covariates and predictive covariates simultaneously. In this paper, we propose a new family of covariate-adjusted response-adaptive (CARA) designs that incorporate both prognostic and predictive covariates and the responses. It is important to note that the predictive biomarkers and prognostic biomarkers play different roles in the new designs. The advantages of the proposed methods are demonstrated via numerical studies, and some further statistical issues are also discussed.

A 48-Hour Vegan Diet Challenge in Healthy Women and Men Induces a BRANCH-Chain Amino Acid Related, Health Associated, Metabolic Signature

SCOPE

Research is limited on diet challenges to improve health. A short-term, vegan protein diet regimen nutritionally balanced in macronutrient composition compared to an omnivorous diet is hypothesized to improve metabolic measurements of blood sugar regulation, blood lipids, and amino acid metabolism.

METHODS AND RESULTS

This randomized, cross-over, controlled vegan versus animal diet challenge is conducted on 21 (11 female,10 male) healthy participants. Fasting plasma is measured during a 3 d diet intervention for clinical biochemistry and metabonomics. Intervention diet plans meet individual caloric needs. Meals are provided and supervised. Diet compliance is monitored.

CONCLUSIONS

The vegan diet lowers triglycerides, insulin and homeostatic model assessment (HOMA-IR), bile acids, elevated magnesium levels, and changed branched-chain amino acids (BCAAs) metabolism (p < 0.05), potentiating insulin and blood sugar control after 48 h. Cholesterol control improves significantly in the vegan versus omnivorous diets. Plasma amino acid and magnesium concentrations positively correlate with dietary amino acids. Polyunsaturated fatty acids and dietary fiber inversely correlate with insulin, HOMA-IR, and triglycerides. Nutritional biochemistries, BCAAs, insulin, and HOMA-IR are impacted by sexual dimorphism. A health-promoting, BCAA-associated metabolic signature is produced from a short-term, healthy, controlled, vegan diet challenge when compared with a healthy, controlled, omnivorous diet.

Efficacy and safety of febuxostat for prevention of tumor lysis syndrome in patients with malignant tumors receiving chemotherapy: a phase III, randomized, multi-center trial comparing febuxostat and allopurinol

BACKGROUND

Control of serum uric acid (sUA) levels is very important during chemotherapy in patients with malignant tumors, as the risks of tumor lysis syndrome (TLS) and renal events are increased with increasing levels of sUA. We investigated the efficacy and safety of febuxostat, a potent non-purine xanthine oxidase inhibitor, compared with allopurinol for prevention of hyperuricemia in patients with malignant tumors, including solid tumors, receiving chemotherapy in Japan.

METHODS

An allopurinol-controlled multicenter, open-label, randomized, parallel-group comparative study was carried out. Patients with malignant tumors receiving chemotherapy, who had an intermediate risk of TLS or a high risk of TLS and were not scheduled to be treated with rasburicase, were enrolled and then randomized to febuxostat (60 mg/day) or allopurinol (300 or 200 mg/day). All patients started to take the study drug 24 h before chemotherapy. The primary objective was to confirm the non-inferiority of febuxostat to allopurinol based on the area under the curve (AUC) of sUA for a 6-day treatment period.

RESULTS

Forty-nine and 51 patients took febuxostat and allopurinol, respectively. sUA decreased over time after initiation of study treatment. The least squares mean difference of the AUC of sUA between the treatment groups was -33.61 mg h/dL, and the 95 % confidence interval was -70.67 to 3.45, demonstrating the non-inferiority of febuxostat to allopurinol. No differences were noted in safety outcomes between the treatment groups.

CONCLUSION

Febuxostat demonstrated an efficacy and safety similar to allopurinol in patients with malignant tumors receiving chemotherapy.

TRIAL REGISTRY

http://www.clinicaltrials.jp ; Identifier: JapicCTI-132398.