Design and logistical considerations for the randomized adaptive non-inferiority storage-duration-ranging CHIlled Platelet Study.

BACKGROUND: Platelet transfusion is a potentially life-saving therapy for actively bleeding patients, ranging from those undergoing planned surgical procedures to those suffering unexpected traumatic injuries. Platelets are currently stored at room temperature (20°C-24°C) with a maximum storage duration of 7 days after donation. The CHIlled Platelet Study trial will compare the efficacy and safety of standard room temperature-stored platelets with platelets that are cold-stored (1°C-6°C), that is, chilled, with a maximum of storage up to 21 days in adult and pediatric patients undergoing complex cardiac surgical procedures. METHODS/RESULTS: CHIlled Platelet Study will use a Bayesian adaptive design to identify the range of cold storage durations for platelets that are non-inferior to standard room temperature-stored platelets. If cold-stored platelets are non-inferior at durations greater than 7 days, a gated superiority analysis will identify durations for which cold-stored platelets may be superior to standard platelets. We present example simulations of the CHIlled Platelet Study design and discuss unique challenges in trial implementation. The CHIlled Platelet Study trial has been funded and will be implemented in approximately 20 clinical centers. Early randomization to enable procurement of cold-stored platelets with different storage durations will be required, as well as a platelet tracking system to eliminate platelet wastage and maximize trial efficiency and economy. DISCUSSION: The CHIlled Platelet Study trial will determine whether cold-stored platelets are non-inferior to platelets stored at room temperature, and if so, will determine the maximum duration (up to 21 days) of storage that maintains non-inferiority. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04834414.

The design of an adaptive clinical trial to evaluate the efficacy of platelets stored at low temperature in surgical patients.

BACKGROUND: Storage of platelets at 4°C compared with 22°C may increase both hemostatic activity and storage duration; however, the maximum duration of cold storage is unknown. We report the design of an innovative, prospective, randomized, Bayesian adaptive, "duration finding" clinical trial to evaluate the efficacy and maximum duration of storage of platelets at 4°C. METHODS: Patients undergoing cardiac surgery and requiring platelet transfusions will be enrolled. Patients will be randomized to receive platelets stored at 22°C up to 5 days or platelets stored at 4°C up to 5 days, 10 days, or 15 days. Longer durations of cold storage will only be used if shorter durations at 4°C appear noninferior to standard storage, based on a four-level clinical hemostatic efficacy score with a NIM of a half level. A Bayesian linear model is used to estimate the hemostatic efficacy of platelet transfusions based on the actual duration of storage at 4°C. RESULTS: The type I error rate, if platelets stored at 4°C are inferior, is 0.0247 with an 82% probability of early stopping for futility. With a maximum sample size of 1,500, the adaptive trial design has a power of over 90% to detect noninferiority and a high probability of correctly identifying the maximum duration of storage at 4°C that is noninferior to 22°C. CONCLUSION: An adaptive, duration-finding trial design will generate Level I evidence and allow the determination of the maximum duration platelet storage at 4°C that is noninferior to standard storage at 22°C, with respect to hemostatic efficacy. The adaptive trial design helps to ensure that longer cold storage durations are only explored once substantial supportive data are available for the shorter duration(s) and that the trial stops early if continuation is likely to be futile.

Dose-Finding Quantitative 18F-FDG PET Imaging Study with the Oral Pan-AKT Inhibitor GSK2141795 in Patients with Gynecologic Malignancies.

UNLABELLED: AKT (a serine/threonine-specific protein kinase) regulates many cellular processes contributing to cytotoxic drug resistance. This study's primary objective examined the relationship between GSK2141795, an oral, pan-AKT inhibitor, and (18)F-FDG PET markers of glucose metabolism in tumor tissue to determine whether (18)F-FDG PET could be used to guide personalized dosing of GSK2141795. Biomarker analysis of biopsies was also undertaken. METHODS: Twelve patients were enrolled in 3 cohorts; all underwent dynamic (18)F-FDG PET scans and serial pharmacokinetic sampling at baseline, week 2, and week 4 with tumor biopsies before treatment and at week 4. Response was evaluated by RECIST v1.1 and Gynecologic Cancer Intergroup criteria. Biopsy samples were analyzed for mutations and protein expression. RESULTS: GSK2141795 did not significantly influence blood glucose levels. No dose-response relationship was observed between GSK2141795 pharmacokinetics and (18)F-FDG PET pharmacodynamic measures; however, an exposure-response relationship was seen between maximum drug concentrations and maximal decrease in (18)F-FDG uptake in the best-responding tumor. This relationship also held for pharmacokinetic parameters of exposure and 1,5-anhydroglucitol (a systemic measure of glucose metabolism). Phospho-AKT upregulation at week 4 in biopsies confirmed AKT inhibition by GSK2141795. Single-agent activity was observed with a clinical benefit rate of 27% (3/11) and 30% (3/10) CA125 response in the study's platinum-resistant ovarian patients. AKT pathway activation by PIK3CA/PIK3R1 mutation did not correlate with clinical activity, whereas RAS/RAF pathway mutations did segregate with resistance to AKT inhibition. CONCLUSION: GSK2141795 demonstrated an exposure-response relationship with decreased (18)F-FDG uptake and is active and tolerable. This study's design integrating (18)F-FDG PET, pharmacokinetics, and biomarker analyses demonstrates the potential for clinical development for personalized treatment.

Effects of particle size, food, and capsule shell composition on the oral bioavailability of dabrafenib, a BRAF inhibitor, in patients with BRAF mutation-positive tumors.

Dabrafenib is a small-molecule inhibitor of BRAF kinase activity that is currently being developed for the treatment of BRAF V600 mutation-positive melanoma. This clinical, open-label, two-cohort (n = 14 per cohort), randomized study was designed to evaluate the effect of drug substance particle size, and food on the plasma pharmacokinetics of a single oral dose of dabrafenib in patients with BRAF V600 mutation-positive solid tumors. In addition, an exploratory cross-cohort comparison of the relative bioavailability of single-dose dabrafenib administered in gelatin and hydroxypropyl methylcellulose (HPMC) capsules was performed. Higher bioavailability was noted with nonmicronized drug substance (larger particle size), under fasting conditions, and with HPMC capsules. Initial dissolution results at pH 1.2 showed higher dissolution of gelatin relative to HPMC capsules inconsistent with clinical data. Subsequent in vitro dissolution studies were conducted in fasted-state simulated gastric fluid over a 24-h period and showed that HPMC capsules reached a higher percentage of dabrafenib dissolved than gelatin capsules. The presence of HPMC is believed to inhibit precipitation of dabrafenib as the freebase, thereby maintaining a supersaturated solution over an extended period of time. Dabrafenib has been administered in pivotal clinical studies on an empty stomach using micronized drug substance in HPMC capsules.