Therapy with mycophenolate mofetil for refractory acute and chronic GVHD.

We evaluated the pharmacokinetics and efficacy of oral mycophenolate mofetil (MMF) for treatment of refractory GVHD. In a prospective study of acute GVHD, 9 of 19 patients (47%) had a response and 10 (53%) had no improvement. Survival at 6 and 12 months after the start of MMF was 37 and 16%, respectively.

ISA247: quality of life results from a phase II, randomized, placebo-controlled study.

Background: Psoriasis is a chronic skin condition that can negatively affect a patient's quality of life (QoL), often hindering social functioning. ISA247, a novel psoriatic agent, has shown clinical efficacy in moderate to severe psoriasis sufferers, but its effect on QoL is currently not reported.

Objective: The objective of this study was to assess the effect of ISA247 on the QoL in patients with stable, plaque-type psoriasis.

Next-generation calcineurin inhibitors for ophthalmic indications.

Calcineurin inhibitors (CNIs) are potent immunosuppressants that reversibly inhibit T-cell proliferation and prevent the release of pro-inflammatory cytokines by blocking the activity of calcineurin, a ubiquitous enzyme that is found in cell cytoplasm. CNIs can be highly effective in immune-mediated ophthalmic diseases such as uveitis, dry eye syndrome and inflammatory blepharitis, as well as for the prevention of rejection in corneal transplants. ISA-247/LX-211 is a novel CNI that is in Phase III clinical development for the treatment of various forms of non-infectious uveitis.

A randomized, multicenter, double-blind, placebo-controlled phase 2 trial of ISA247 in patients with chronic plaque psoriasis.

Background: Use of current oral calcineurin inhibitors for the treatment of psoriasis is limited by toxicity.

Objective: Evaluate the safety and efficacy of ISA247, a new oral calcineurin inhibitor, in plaque psoriasis patients.

Methods: This 12-week, randomized, double-blind, placebo-controlled, parallel-group study included 201 plaque psoriasis patients with > or = 10% body surface area involvement.

The novel calcineurin inhibitor ISA247: a more potent immunosuppressant than cyclosporine in vitro.

ISA247 is a novel cyclosporine analog. In this study we compare, in vitro, the effects of ISA247 on immune function with those of cyclosporine. Whole blood from cynomolgus monkeys (n = 5) was incubated with different concentrations of ISA247 or cyclosporine and stimulated with different mitogens in culture medium.

The portal immunosuppressive storm: relevance to islet transplantation?

Outcomes in clinical islet transplantation improved substantially with the introduction of combined sirolimus and tacrolimus immunosuppression. However, multiple islet preparations are often required to achieve insulin independence, suggesting that islet engraftment may not be optimal when these agents are absorbed via the portal vein. The current study was designed to assess the differential concentrations of immunosuppressive drugs within the portal and systemic circulations of a large animal model, to assess the local concentrations of drugs to which islets are exposed early after implantation.

Amelioration of accelerated collagen induced arthritis by a novel calcineurin inhibitor, ISA(TX)247.

Objective: To examine the efficacy and toxicity of ISA(TX)247, a novel calcineurin inhibitor, in comparison to cyclosporine (cyclosporin A, CSA) and placebo in established collagen induced arthritis. ISA(TX)247 has up to 3-fold greater potency than CSA in an in vitro whole blood calcineurin inhibition assay and in in vivo solid organ and cell transplantation models. Phase I clinical trials show no discernible nephrotoxicity.

Requirements for therapeutic drug monitoring of sirolimus, an immunosuppressive agent used in renal transplantation.

Background: On September 15, 1999, sirolimus received approval from the US Food and Drug Administration (FDA) for marketing as an immunosuppressive agent. As with any chronically administered medication, the question arises whether therapeutic drug monitoring (TDM) is required for optimal therapy. In the case of sirolimus, there are data to suggest that TDM may be beneficial in some patients.

Comparison of steady-state trough sirolimus samples by HPLC and a radioreceptor assay.

Objectives: We have previously identified a minor immunophilin of 52 kDa molecular weight capable of binding tacrolimus and sirolimus. Because immunophilins are capable of binding both parent drug and metabolites and HPLC assays are typically used to assess parent drug in clinical situations, we used this immunophilin in a radioreceptor assay (RRA) to determine if any metabolites not included in the HPLC measurement would bind to the immunophilin and be associated with thrombocytopenia in patients receiving sirolimus.

Design And Methods: We tested 51 steady-state trough whole blood samples from non-thrombocytopenic patients and 51 steady-state trough samples from thrombocytopenic patients and compared them to HPLC measurements of parent drug in the same samples.

Minor immunophilin binding of tacrolimus and sirolimus metabolites.

Objectives: We have previously identified three minor immunophilins of molecular weights 37 kDa, 14 kDa, and 5-8 kDa capable of binding tacrolimus and sirolimus.

Design And Methods: When tested against pure preparations of five sirolimus metabolites, the 14 kDa protein had almost no cross-reactivity, the 37 kDa protein cross-reacted from a high of 23.2% to <10% and the 5-8 kDa protein cross-reacted from <10% to 46.

Pharmacokinetics and metabolism of sirolimus.

Sirolimus (rapamycin, Rapamune) is a potent immunosuppressive drug that received marketing approval from the US Food and Drug Administration on September 15, 1999. Research into defining its pharmacokinetic (PK) behavior, interaction with other agents, and metabolism is ongoing. It has been established that oral doses of both liquid and solid formulation are rapidly, though incompletely and variably, absorbed.

Current opinions on therapeutic drug monitoring of immunosuppressive drugs.

The pharmacokinetics of the immunosuppressive drugs cyclosporine, tacrolimus, mycophenolate mofetil (MMF), and sirolimus are complex and unpredictable. A narrow therapeutic index unique to each patient, as well as variable absorption, distribution, and elimination, are characteristics of these drugs. Therapeutic drug monitoring plays a key role in helping clinicians maintain blood and plasma levels of immunosuppressive drugs within their respective therapeutic ranges.

Trace element contamination of total parenteral nutrition. 2. Effect of storage duration and temperature.

Background: Patients who receive home total parenteral nutrition (TPN) frequently are supplied with solutions up to 30 days in advance of anticipated use. The purpose of this study was to determine the stability of trace elements relative to time and temperature conditions, in a typical adult TPN solution stored in a usual home environment by examining variations in delivery of intended trace elements and inadvertent trace element contamination.

Methods: Trace element concentrations were determined using inductively coupled plasma-mass spectrometry technology.

Trace element contamination of total parenteral nutrition. 1. Contribution of component solutions.

Background: Trace elements have been shown to contaminate total parenteral nutrition (TPN) solutions.

Methods: This study used the multi-elemental technology of inductively coupled plasma-mass spectrometry to demonstrate the extent to which trace elements were present in amounts above (ie, as contaminants) or below expected levels in eight TPN component solutions.

Results: Of the 66 trace elements scanned, there were 12 trace element contaminants in amounts >1 microg/L (zinc, copper, manganese, chromium, selenium, boron, aluminum, titanium, barium, vanadium, arsenic, and strontium) in the eight component solutions studied.

Study of FK-binding protein: FK506-metabolite complexes by electrospray mass spectrometry: correlation to immunosuppressive activity.

Electrospray ionization mass spectrometry was used to study several non-covalent FK-binding protein (FKBP) immunosuppressant complexes in the gas phase. Relative FKBP binding affinities were determined from the signal ratio for the 7+ charge states of bound and unbound complexes as a function of capillary exit voltage. All complexes displayed a 1:1 binding stoichiometry.

Clinical validation of the Helikit: a 13C urea breath test used for the diagnosis of Helicobacter pylori infection.

Objective: To assess the clinical performance of the Helikit, a 13C urea breath test, in the diagnosis of Helicobacter pylori infection.

Methods: A total of 205 participants were assessed in Canada and Korea for H. pylori infection status by endoscopy, or a combination of IgG ELISA and CLO test, as well as by the Helikit.

Effect of combined immunosuppressive drug therapy on small intestinal nutrient transport in the rat.

Objective: Prevention of rejection and preservation of graft function remain as obstacles to clinical small intestinal transplantation (SIT). This study evaluated the effects of combined immunosuppressive agents (FK506, Rapamycin, and Mycophenolate Mofetil) on intestinal function and animal well being.

Methods: Screening for additive toxicity was done in experiment one (D1, n = 10); doses were: FK506 0.

Tacrolimus metabolite cross-reactivity in different tacrolimus assays.

Objectives: Tacrolimus (FK506) is an immunosuppressive drug with great clinical promise. There is a controversy regarding the role of tacrolimus metabolites in immunosuppression and toxicity, and immunoassays and immunophilin binding assays have not been adequately tested for metabolite cross-reactivity. Methods are limited to HPLC and HPLC-MS for quantifying the parent drug.

Oral administration of rapamycin and cyclosporine differentially alter intestinal function in rabbits.

The immunosuppressive drugs rapamycin (Rap) and cyclosporine A (CsA) are used clinically to modify or abolish immune-mediated functions. This study examined the effect of orally administered regimens of Rap, CsA, and a combination of Rap/CsA on intestinal function in male New Zealand white rabbits. Animals received oral doses of CsA (15 mg/kg/body weight/day), low-dose (LD) and high-dose (HD) Rap (0.

The monitoring of immunosuppressive drugs: a pharmacodynamic approach.

Pharmacodynamic monitoring measures biologic response to a drug, which, alone or coupled with pharmacokinetics, provides a novel method for the optimization of drug dosing. Pharmacodynamic monitoring has been investigated by us and other investigators on primarily five immunosuppressive drugs: cyclosporine (CsA), mycophenolate mofetil (MMF), rapamycin (RAPA), azathioprine (AZA), and methylprednisolone (MP). The pharmacodynamic monitoring of CsA and MMF involves measurement of the activity of the enzymes calcineurin and inosine monophosphate dehydrogenase, respectively.

Competitive immunoassay for cyclosporine using capillary electrophoresis with laser induced fluorescence polarization detection.

Frequent monitoring of immunosuppressive drug cyclosporine A (CsA) in blood samples of tissue transplant patients is required in clinical practice because of the narrow therapeutic range between the immunosuppressive effect and the toxic effect of this drug. We describe a competitive immunoassay capillary electrophoresis (CE) with laser induced fluorescence polarization detection method, which is rapid and sensitive for the determination of CsA. The method is based on the competitive immunochemical reaction between the analyte and fluorescent hapten (CsA*) with the antibody, CE separation of the antibody bound and free fluorescent CsA*, followed by the laser induced fluorescence polarization detection (LIFP) of the fluorescent species.

Rapamycin: distribution, pharmacokinetics and therapeutic range investigations: an update.

Based on the findings above, a number of conclusions can be made regarding the distribution, pharmacokinetics, and therapeutic range investigations with RAPA: (a) the majority of the drug is sequestered in erythrocytes, resulting in whole blood concentrations being considerably higher than plasma concentrations; (b) the drug is metabolized by the same cytochrome P450 3A enzyme involved in the metabolism of CsA and FK506. Metabolites are primarily simple demethylations and hydroxylations with 41-O-demethyl RAPA being the major metabolite both in vivo and in vitro; (c) the drug has a relatively long half-life in both humans and animals with 24-h trough concentrations being within the analytical range of HPLC when immunosuppressive doses are administered; (d) the drug exhibits a degree of proportionality between trough concentrations and dose; (e) a strong correlation exists between area under the concentration-time curve and trough blood concentration at steady state; (f) trough concentrations of the drug appear to be related to immunosuppressive efficacy and drug-related side effects; (g) the nephro- and neurotoxic properties of CsA are not augmented by concurrent treatment with RAPA; and (h) phase IIB trial results have shown a decrease of acute rejection episodes from 40% to < 10% among patients treated with full-dose CsA plus RAPA. The studies described here should provide a basis for the establishment of therapeutic monitoring protocols for RAPA.