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Chimeric antigen receptor (CAR) T-cell therapy is a human gene therapy product where T cells from a patient are genetically modified to enable them to recognize desired target antigen(s) more effectively. In recent years, promising antitumor activity has been seen with autologous CAR T cells. Since 2017, six CAR T-cell therapies for the treatment of hematological malignancies have been approved by the Food and Drug Administration (FDA). Despite the rapid progress of CAR T-cell therapies, considerable statistical challenges still exist for this category of products across all phases of clinical development that need to be addressed. These include (but not limited to) dose finding strategy, implementation of the estimand framework, use of real-world data in contextualizing single-arm CAR T trials, analysis of safety data and long-term follow-up studies. This paper is the first step in summarizing and addressing these statistical hurdles based on the development of the six approved CAR T-cell products., (© 2024. The Author(s), under exclusive licence to The Drug Information Association, Inc.)

A study of burn thresholds from superficially penetrating radio-frequency (RF) energy at 8.2 and 95 GHz for swine skin was conducted. The study determined the thresholds for superficial, partial-thickness, and full-thickness burn severities after 5 seconds of exposure at power densities of 4-30 W/cm 2 and 2-15 W/cm 2 at 8.2 and 95 GHz, respectively. There were significant differences in he burn thresholds at the different severities between the two frequencies due to the large difference in energy penetration depths. Biopsies were collected from each burn site at 1, 24, 72, and 168 hr post exposure. Each sample was assessed by a burn pathologist against 20 histological factors to characterize the damage resulting from these RF overexposures. A one-dimensional, layered digital phantom that utilized realistic values for dielectric and thermal properties was used to explain some observed thresholds. The results of the heating and cooling response of the animal model and histology scores of each exposure are provided to enhance future efforts at simulation of RF overexposures and to establish damage thresholds., (Creative Commons Attribution license.)

With the advent of cancer immunotherapy, some special features including delayed treatment effect, cure rate, diminishing treatment effect and crossing survival are often observed in survival analysis. They violate the proportional hazard model assumption and pose a unique challenge for the conventional trial design and analysis strategies. Many methods like cure rate model have been developed based on mixture model to incorporate some of these features. In this work, we extend the mixture model to deal with multiple non-proportional patterns and develop its geometric average hazard ratio (gAHR) to quantify the treatment effect. We further derive a sample size and power formula based on the non-centrality parameter of the log-rank test and conduct a thorough analysis of the impact of each parameter on performance. Simulation studies showed a clear advantage of our new method over the proportional hazard based calculation across different non-proportional hazard scenarios. Moreover, the mixture modeling of two real trials demonstrates how to use the prior information on the survival distribution among patients with different biomarker and early efficacy results in practice. By comparison with a simulation-based design, the new method provided a more efficient way to compute the power and sample size with high accuracy of estimation. Overall, both theoretical derivation and empirical studies demonstrate the promise of the proposed method in powering future innovative trial designs., (© 2023 John Wiley & Sons Ltd.)

Chimeric antigen receptor T cell (CAR-T) therapies, including axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel), are innovative treatments for patients with relapsed or refractory (r/r) large B cell lymphoma (LBCL). Following initial regulatory approvals, real-world evidence (RWE) of clinical outcomes with these therapies has been accumulating rapidly. Notably, several large registry studies have been published recently. Here we comprehensively describe clinical outcomes with approved CAR-T therapies in patients with r/r LBCL using available RWE. We systematically searched Embase, MEDLINE, and 15 conference proceedings to identify studies published between 2017 and July 2022 that included ≥10 patients with r/r LBCL treated with commercially available CAR-T therapies. Eligible study designs were retrospective or prospective observational studies. Key outcomes of interest were objective response rate (ORR), complete response (CR) rate, overall survival (OS), progression-free survival (PFS), cytokine release syndrome (CRS), and immune effector cell-associated neurotoxicity syndrome (ICANS). Random-effects meta-analyses were used to compare real-world outcomes with those of pivotal clinical trials and to compare clinical outcomes associated with axi-cel and tisa-cel. Study cohort mapping was conducted to avoid including patients more than once. Of 76 cohorts we identified, 46 reported patients treated specifically with either axi-cel or tisa-cel, with 39 cohorts (n = 2754 patients) including axi-cel and 20 (n = 1649) including tisa-cel. No studies of liso-cel that met the inclusion criteria were identified during the search period. One-half of the tisa-cel cohorts were European, compared with 33% of the axi-cel cohorts. Among studies with available data, axi-cel had a significantly shorter median time from apheresis to CAR-T infusion than tisa-cel. Despite including broader patient populations, real-world effectiveness and safety of both axi-cel and tisa-cel were consistent with data from the pivotal clinical trials. Comparative meta-analysis of axi-cel versus tisa-cel demonstrated adjusted hazard ratios for OS and PFS of .60 (95% confidence interval [CI], .47 to .77) and .67 (95% CI, .57 to .78), respectively, both in favor of axi-cel. Odds ratios (ORs) for ORR and CR rate, both favoring axi-cel over tisa-cel, were 2.05 (95% CI, 1.76 to 2.40) and 1.70 (95% CI, 1.46 to 1.96), respectively. The probability of grade ≥3 CRS was comparable with axi-cel and tisa-cel, whereas axi-cel was associated with a higher incidence of grade ≥3 ICANS (OR, 3.95; 95% CI, 3.05 to 5.11). Our meta-analysis indicates that CAR-T therapies have manageable safety profiles and are effective in a wide range of patients with r/r LBCL, and that axi-cel is associated with improved OS and PFS and increased risk of grade ≥3 ICANS compared with tisa-cel. Limitations of this study include nonrandomized treatments, potential unknown prognostic factors, and the lack of available real-world data for liso-cel., (Copyright © 2023. Published by Elsevier Inc.)