Carbon tetrachloride-induced increase in the antitumor activity of cyclophosphamide in mice: a pharmacokinetic study

Immunosuppression for in vivo research: state-of-the-art protocols and experimental approaches

Almost every experimental treatment strategy using non-autologous cell, tissue or organ transplantation is tested in small and large animal models before clinical translation. Because these strategies require immunosuppression in most cases, immunosuppressive protocols are a key element in transplantation experiments. However, standard immunosuppressive protocols are often applied without detailed knowledge regarding their efficacy within the particular experimental setting and in the chosen model species. Optimization of such protocols is pertinent to the translation of experimental results to human patients and thus warrants further investigation. This review summarizes current knowledge regarding immunosuppressive drug classes as well as their dosages and application regimens with consideration of species-specific drug metabolization and side effects. It also summarizes contemporary knowledge of novel immunomodulatory strategies, such as the use of mesenchymal stem cells or antibodies. Thus, this review is intended to serve as a state-of-the-art compendium for researchers to refine applied experimental immunosuppression and immunomodulation strategies to enhance the predictive value of preclinical transplantation studies.

The combination of cyclophosphamide and human T cells genetically engineered to target CD19 can eradicate established B-cell lymphoma

T cells genetically engineered to express tumour-targeting receptors are attractive anti-cancer therapeutic agents. Human T cells engrafted with a chimeric receptor specific for the B-cell lymphoma antigen CD19 fused to the CD3zeta receptor (aCD19z) are functional in vitro. Current successful clinical protocols targeting melanoma use pre-conditioning chemotherapy in combination with T cells. This study demonstrated that interleukin-2 expanded aCD19z T cells combined with cyclophosphamide effectively treated five-day established Raji B-cell lymphoma in an immunocompromised model system with 50% of mice surviving >100 days. This observation strongly supports the combination of antibody targeted T cells with chemotherapy as a novel approach for the therapy of CD19(+) B-cell malignancies.

Effect of body weight on the pharmacokinetics of cyclophosphamide in breast cancer patients

Cyclophosphamide pharmacokinetics have been studied in 16 female patients with advanced breast cancer. The group included 7 patients who were greater than 20%, less than or equal to 30% over ideal body weight and 5 patients who were greater than 30% over ideal body weight. Cyclophosphamide plasma elimination half-lives ranged between 152 and 984 min (mean 457 min), the apparent volume of distribution between 19.1 and 62.3 1 (mean 36.1 1), and plasma clearance between 25.9 and 166.6 ml/min (mean 69.5 ml/min). There was a significant positive correlation (r = 0.624, P = 0.010) between body weight and plasma elimination half-life, and a significant negative correlation between body weight and cyclophosphamide clearance when normalized to body surface area (r = 0.578, P = 0.019) or normalized to ideal body weight (r = 0.531, P = 0.0345). The apparent volume of distribution did not correlate with body weight. The results show that cyclophosphamide disposition is altered in patients with increased body weight.