PK/PD modeling of FXI antisense oligonucleotides to bridge the dose-FXI activity relation from healthy volunteers to end-stage renal disease patients.

IONIS-FXIRX (BAY2306001) is an antisense oligonucleotide that inhibits the synthesis of coagulation factor XI (FXI) and has been investigated in healthy volunteers and patients with end-stage renal disease (ESRD). FXI-LICA (BAY2976217) shares the same RNA sequence as IONIS-FXIRX but contains a GalNAc-conjugation that facilitates asialoglycoprotein receptor (ASGPR)-mediated uptake into hepatocytes. FXI-LICA has been studied in healthy volunteers and is currently investigated in patients with ESRD on hemodialysis. We present a model-informed bridging approach that facilitates the extrapolation of the dose-exposure-FXI relationship from IONIS-FXIRX to FXI-LICA in patients with ESRD and, thus, supports the selection of FX-LICA doses being investigated in patients with ESRD. A two-compartment pharmacokinetic (PK) model, with mixed first- and zero-order subcutaneous absorption and first-order elimination, was combined with an indirect response model for the inhibitory effect on the FXI synthesis rate via an effect compartment. This PK/pharmacodynamic model adequately described the median trends, as well as the interindividual variabilities for plasma drug concentration and FXI activity in healthy volunteers of IONIS-FXIRX and FXI-LICA, and in patients with ESRD of IONIS-FXIRX . The model was then used to predict dose-dependent steady-state FXI activity following repeat once-monthly doses of FXI-LICA in a virtual ESRD patient population. Under the assumption of similar ASGPR expression in patients with ESRD and healthy volunteers, doses of 40 mg, 80 mg, and 120 mg FXI-LICA are expected to cover the target range of clinical interest for steady-state FXI activity in the phase IIb study of FXI-LICA in patients with ESRD undergoing hemodialysis.

Seventy-five years of Resochin in the fight against malaria.

The four different forms of human malaria have threatened humanity since time immemorial and to this day, they exact a death toll of one to three million people annually. Synthetic anti-malarial agents have been in development since early 1900. Perhaps the most successful and widely used drug, Resochin (chloroquine), was discovered 75 years ago; for a long time, it was the drug of choice and to this day, it is still used in many regions of the world as a reliable treatment against simpler forms of malaria. In regions where it has not been in use against malaria tropica for quite some time due to the development of resistances, it has regained some of its efficacy. This review traces the discovery and the mechanism of action of this substance, illustrates the significance of malaria today, and underlines the need for controlled and reliable therapeutic measures.

Targeting the neural cell adhesion molecule in cancer.

NCAM is a tumour associated antigen expressed on small cell lung cancer, neuroblastoma, rhabdomyosarkoma, brain tumours, multiple myelomas and acute myeloid leukaemia. Constant and strong expression of NCAM is a prerequisite for the development of antibody-based immunotherapies. From the spectrum of existing anti-NCAM compounds, radioimmunoconjugates and immunotoxins represent the clinically most advanced and successful strategies. Here we provide an overview of the evolving field of anti-NCAM immunotherapy for cancer and discuss its indications and limitations.

Fludarabine in combination with alemtuzumab is effective and feasible in patients with relapsed or refractory B-cell chronic lymphocytic leukemia: results of a phase II trial.

PURPOSE: To determine the efficacy and safety of a newly developed concomitant administration of fludarabine and alemtuzumab (FluCam) in patients with relapsed or refractory B-cell chronic lymphocytic leukemia (B-CLL). PATIENTS AND METHODS: A total of 36 patients were treated in this phase II study (median age, 61.47 years; mean number of prior chemotherapies, 2.6; Binet stage C, n = 28). After an initial dose escalation of alemtuzumab over 3 days, alemtuzumab 30 mg and fludarabine 30 mg/m2 were administered on 3 consecutive days. Treatment was repeated after 28 days for up to six cycles. Restaging (following National Cancer Institute criteria) was carried out after cycles 2 and 4 and 1 month after the end of treatment. RESULTS: The overall response rate was 83% (11 complete responses, 19 partial responses, one stable disease, and five progressive diseases). Two patients with progressive disease developed fungal pneumonias, and one patient died as a result of Escherichia coli sepsis. Two subclinical cytomegalovirus reactivations occurred. CONCLUSION: The new FluCam regimen is effective and feasible in patients with relapsed and refractory B-CLL.

Localization of 131I-labelled monoclonal antibody ERIC1 in a subcutaneous xenograft model of neuroblastoma in SCID mice.

PURPOSE: To evaluate a novel strategy of immunolocalization of human neuroblastoma by targeting the neural cell adhesion molecule (NCAM), which is over-expressed on neuroblastoma. METHODS: NCAM expression on the cell surface of established neuroblastoma cells was shown by flow cytometry. A SCID mouse model using IMR5-75 neuroblastoma cells to induce subcutaneous tumour growth was established. 131I was used to label monoclonal NCAM specific ERIC1 antibodies generating the 131I-ERIC1 antibody, which showed a high affinity to NCAM also after labelling (KD=9 x 10(-8) mol . l(-1)). RESULTS: Measurement of organ-specific radioactivity showed low organ-specific uptake (5.33%ID/g (percent of injected dose per gram of tissue) after 72 h), which continuously decreased over the 96 h investigation period, demonstrating clearance of radioactivity. In contrast, tumours accumulated radioactivity continuously up to a peak of 42.07%ID/g at the 96 h time point (31.07%ID/g at 72 h). This specific uptake could be blocked by application of unlabelled ERIC1 antibodies. Measurement of blood specific radioactivity revealed a characteristic clearance over the first 72 h. With 37 Gy, tumour-specific radioactivity reached therapeutic doses after 96 h. CONCLUSIONS: These results indicate that 131I-labelled ERIC1 has the ability to probe NCAM-expressing tumour cells in vivo with high efficiency and is a promising reagent for the diagnosis and treatment of NCAM-positive human tumours, especially for neuroblastoma.

Effect of Diet on Serum Creatinine in Healthy Subjects During a Phase I Study.

Creatinine is widely used as an indirect marker of renal function. However, interfering factors such as diet, exercise and problems with the assay can generate false results and misinterpretation of real kidney function. In this article, we report the dietary effects on serum creatinine during a phase I single dose escalation study and discuss the reasons why serum creatinine should be measured under fasting conditions.

SEARCH: a phase III, randomized, double-blind, placebo-controlled trial of sorafenib plus erlotinib in patients with advanced hepatocellular carcinoma.

PURPOSE: To compare the clinical outcomes of sorafenib plus either erlotinib or placebo in patients with advanced hepatocellular carcinoma (HCC) in a multicenter, multinational, randomized, phase III trial. PATIENTS AND METHODS: Patients with advanced HCC and underlying Child-Pugh class A cirrhosis, who were naive to systemic treatment (N = 720), were randomly assigned to sorafenib plus either erlotinib (n = 362) or placebo (n = 358). The primary end point was overall survival (OS). RESULTS: Median OS was similar in the sorafenib plus erlotinib and sorafenib plus placebo groups (9.5 v 8.5 months, respectively; hazard ratio [HR], 0.929; P = .408), as was median time to progression (3.2 v 4.0 months, respectively; HR, 1.135; P = .18). In the sorafenib/erlotinib arm versus the sorafenib/placebo arm, the overall response rate trended higher (6.6% v 3.9%, respectively; P = .102), whereas the disease control rate was significantly lower (43.9% v 52.5%, respectively; P = .021). The median durations of treatment with sorafenib were 86 days in the sorafenib/erlotinib arm and 123 days in the sorafenib/placebo arm. In the sorafenib/erlotinib and sorafenib/placebo arms, the rates of treatment-emergent serious AEs (58.0% v 54.6%, respectively) and drug-related serious AEs (21.0% v 22.8%, respectively) were similar. AEs matched the known safety profiles of both agents, but rates of rash/desquamation, anorexia, and diarrhea were higher in the sorafenib/erlotinib arm, whereas rates of alopecia and hand-foot skin reaction were higher in the sorafenib/placebo arm. Withdrawal rates for AEs during cycles 1 to 3 were higher in the sorafenib/erlotinib arm. CONCLUSION: Adding erlotinib to sorafenib did not improve survival in patients with advanced HCC.

NK cell depletion diminish tumour-specific B cell responses.

Natural killer (NK) cells can exercise immediate cytotoxicity against malignant cells and thus far modulate the development of tumour directed T cell immunity. To investigate the impact of NK cells on the development of tumour directed B cell immunity mice were immunised with IMR5-75 human neuroblastoma cells with or without prior in vivo NK cell depletion. Flow cytometry analyses gave evidence for an impaired IgG response against the cells immunised with. Dissection of Th1 (IgG2a) and Th2 (IgG1) oriented B cell responses revealed Th1 responses as primarily affected, while Th2 oriented B cell responses as measured by flow cytometry and GD2 ganglioside-specific ELISA were enforced. The data reveal an unexpected impact of NK cells on the development of tumour directed B cell responses. Consequently, NK cell function has also to be taken into account when developing B cell-based cancer immunotherapy.

The novel chimeric anti-NCAM (neural cell adhesion molecule) antibody ch.MK1 displays antitumor activity in SCID mice but does not activate complement-dependent cytolysis (CDC).

A monoclonal chimeric antibody ch.MK1 was generated by immunizing F004 mice expressing human instead of murine IgG1/kappa immunoglobulin constant regions. The novel antibody specifically binds cell surface-expressed human neural cell adhesion molecule (NCAM) as shown by immunoprecipitation, flow cytometry and cytospins. Functional analysis revealed nearly complete absence of complement-dependent cytolysis in ch.MK1 and in all other anti-NCAM antibodies tested for reference (UJ13a, ERIC1, 123C3, ch.5A2, B159), indicating an unexpected and group-specific property of anti-NCAM antibodies. As a most plausible mechanism, posttranslational modification of NCAM by complement-inhibiting polysialic acid is discussed. The antibody ch.MK1 demonstrated significant in vivo activity against NCAM-positive neuroblastoma in SCID mice in presence of human peripheral blood mononuclear cell. In absence of human peripheral blood mononuclear cell no distinct antitumor activity of the antibody alone was observed. In ch.MK1 the cellular component of the immune system seems to be the dominant effector mechanism, whereas complement-dependent cytolysis seems not to be necessarily required for antitumor activity. These observations help us to understand immunotherapeutic mechanisms of native anti-NCAM antibodies and may additionally contribute to the understanding of results of currently ongoing clinical studies with conjugated anti-NCAM antibodies.

Phase I study of a novel pro-apoptotic drug R-etodolac in patients with B-cell chronic lymphocytic leukemia.

R-etodolac is a novel pro-apoptotic agent with potential antitumor activity against B-cell chronic lymphocytic leukemia (B-CLL). This phase I clinical trial was conducted to determine the tolerability, safety, and maximum tolerated dose (MTD) of R-etodolac, administered orally twice a day (BID), in patients with B-CLL. Secondary objectives included evaluating clinical response, pharmacodynamic activity (reduction of lymphocytes), and pharmacokinetic (PK) profile. Forty-three patients were enrolled in the study. The most frequently reported adverse events were diarrhea, rash, pruritus, and headache. Increases in alanine aminotransferase (ALT) were also observed. Adverse events were generally mild and self-limiting, although in an apparent dose-response relationship, grade 2 and 3 gastrointestinal toxicities and grade 3 skin toxicities were reported with the highest dose regimens (1,800 and 2,400 mg BID). Hematologic toxicity was rare. The MTD was determined to be 1,200 mg BID. PK results indicated that oral absorption of R-etodolac was rapid (time to maximum concentration ranged from 2 to 4 h), and the half-life ranged from 5 to 7 h. The increase in maximum concentration, however, was not proportional to the increase in dose. R-etodolac significantly reduced absolute lymphocyte count (ALC) in B-CLL patients in a dose-dependent manner up to 1,800 mg BID and caused partial responses in 2 patients. Further study of R-etodolac as a possible new maintenance therapy or as a part of combination therapy of B-CLL appears warranted.

One step generation of fully chimeric antibodies using Cgamma1- and Ckappa mutant mice.

Humanized antibodies (Abs) are effective drugs against a variety of diseases such as cancer, autoimmune diseases, transplant rejection and others. The most powerful technology to develop humanized Abs is the use of mice that produce humanized Abs. By modifying the genetic background of F004 mice a new mouse substrain was developed for optimized "one step" generation of chimeric humanized monoclonal Abs. The new mice (F004-Jen) demonstrated improved fertility still expressing the human locus at the same level as the parental F004 mouse. The value of these mice for the generation of chimeric Abs was exemplified for a panel of chimeric Abs against the human neural cell adhesion molecule (NCAM): The fully chimeric human IgG1/kappa Ab Ch.MK1 bound to NCAM expressing cells with a K(D)=4.3-8.7 x 10(-8) M and was functionally active as demonstrated by depleting NCAM expressing cells. We also demonstrated that chimeric IgG1/kappa Abs can be induced by hybridoma class switching of IgM producing hybridoma cells, providing an alternative way to chimeric Abs. The present data highlight F004-Jen mice as an efficient tool for "one step" generation of chimeric Abs.

Prolonged remission in a patient with relapsed follicular lymphoma after a single course of rituximab.

BACKGROUND: Rituximab monotherapy can achieve remissions of up to 80% in follicular lymphoma. As the antibody has only been on the market since 1997, long-term observations are still rare. CASE REPORT: We report about a patient with follicular lymphoma who received a single treatment of 4 x 375 mg/m(2) of the monoclonal antibody rituximab without chemotherapy and has been in complete remission (CR) for 8 years. DISCUSSION: This remarkable response duration highlights the efficacy of rituximab monotherapy. A number of recently published studies have indicated that CR of more than 4 years after rituximab monotherapy may be a regularly occurring event. CONCLUSIONS: These patients are likely to represent a yet poorly characterized patient group that profits considerably from rituximab monotherapy.

Implementation and evaluation of a central coordination office for clinical trials in a tertiary care hospital.

BACKGROUND: Controlled clinical trials are essential tools for establishing new standards in patient care. Nevertheless, the majority of cancer patients are not treated within clinical trials. We report about a project now running for 7 years that was started in order to enhance the recruitment of patients into clinical trials, to improve trial-related quality, and to comply with the regulatory issues related to these studies. MATERIAL AND METHODS: We established a Central Coordination Office (CCO) for clinical trials, an associated internal clinical trials review board, a register of active clinical trials, and a computer-based medical information system at our department. RESULTS: Inpatient recruitment into clinical trials at our department improved over the last 7 years from 40% in 1997 to 70% in 2003. The internal review board approved 276 trial projects since its establishment. A clinical trials register is now in its 9th edition. Currently, 50 to 60 clinical trials in oncology/hematology are active while 10 to 20 new trials are being implemented per year. All clinical trials comply with the regulatory requirements, and trial documentation is provided in a timely manner. CONCLUSIONS: The establishment of a CCO for clinical trials substantially improves and maintains patient recruitment into clinical trials and improves the quality of clinical research.

Reduced frequencies and suppressive function of CD4+CD25hi regulatory T cells in patients with chronic lymphocytic leukemia after therapy with fludarabine.

Globally suppressed T-cell function has been described in many patients with cancer to be a major hurdle for the development of clinically efficient cancer immunotherapy. Inhibition of antitumor immune responses has been mainly linked to inhibitory factors present in cancer patients. More recently, increased frequencies of CD4+CD25hi regulatory T cells (Treg cells) have been described as an additional mechanism reducing immunity. We assessed 73 patients with B-cell chronic lymphocytic leukemia (CLL) and 42 healthy controls and demonstrated significantly increased frequencies of cytotoxic T lymphocyte-associated protein 4 (CTLA4+)-, Forkhead box P3 (FOXP3+)-, glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR+)-, CD62L+-, transforming growth factor beta1 (TGF-beta1+)-, interleukin 10 (IL-10+)-Treg cells in patients with CLL, with highest frequencies in untreated or progressing patients presenting with extended disease. Most surprisingly, in the majority of patients with CLL treated with fludarabine-containing therapy regimens the inhibitory function of Treg cells was decreased or even abrogated. In addition, frequencies of Treg cells were significantly decreased after therapy with fludarabine. In light of similar findings for cyclophosphamide the combination of fludarabine and cyclophosphamide might be further exploited in strategies reducing immunosuppression prior to cancer immunotherapy.