Alefacept plus methotrexate for psoriatic arthritis

Effect of methotrexate administration on status of some essential trace elements and antioxidant enzymes in pregnant rats in late gestation

OBJECTIVE

Folate antagonists are widely used in the treatment of various cancerous states. Paucity of data on effect of administration of one such widely used drug, methotrexate (MTX), on the status of essential trace elements and antioxidant enzymes in pregnant women or in pregnant animals prompted us to undertake this study.

METHODS

MTX at a concentration of 5 mg/kg body weight was administered intraperitoneally as single dose to pregnant Sprague-Dawley rats for three consequitive days from day 17 of pregnancy. Control group of pregnant rats received single dose of saline instead of the anti-cancer drug on all the 3 days. After receiving the third dose of drug, the treated rats and control group rats were sacrificed, 1 h after intraperitoneal injection of a cocktail of essential trace elements namely, Cu, Se and Zn administered as a single bolus dose. Blood samples were collected 30 min of trace element cocktail injection, after decapitation and concentrations of trace elements in serum samples were determined by atomic absorption spectrophotometry. Concentrations of antioxidant enzymes, such as superoxide dismutase, glutathione peroxidase and total antioxidant status were determined by specific analytical kits, using spectrophotometry.

RESULTS

In control group(n = 6), serum concentrations of Cu, Se and Zn averaged 2330.5, 614.8 and 2773.2 microg/l, while in study group (n = 6) the concentrations of trace elements averaged 2294, 596 and 2713 microg/l, respectively. Student's t-test did not show any statistical significance (p > 0.05) between various trace element concentrations in control and treated groups. Cu:Zn ratios of control and treated group of rats did not vary significantly as well. Concentrations of superoxide dismutase, glutathione peroxidase in whole blood samples in control rats averaged 165 and 43,260 U/ml, respectively, while in MTX-treated group of animals the corresponding antioxidant enzymes averaged 330.6 and 67,101 U/ml respectively. SOD and GPX values were significantly higher in drug-treated animals compared to controls (Student's t-test, p < 0.05) However, total antioxidant activity was shown to be significantly lower (Student's t-test; p < 0.05) in the drug-treated group compared to control.

CONCLUSIONS

We report for the first time that effect of MTX administration in pregnancy is not associated with significant alteration in disposition of essential trace elements. However, the effect of drug administration on antioxidant enzyme status in pregnant women cannot be excluded while using the drug in clinical states.

Maternal–fetal transport kinetics of methotrexate in perfused human placenta:In vitrostudy

OBJECTIVE

Folate antagonists are widely used in the treatment of diverse cancerous states. A paucity of data on transport characteristics of one such widely used drug, methotrexate, in the human placenta, prompted us to study its permeation characteristics in vitro.

METHODS

Placentas from normal pregnancies were collected post-partum. Methotrexate, along with antipyrine as reference marker were injected as a single bolus (100 microL) into the maternal arterial circulation of isolated perfused placental lobules; perfusate samples were collected from both maternal and fetal circulations over a study period of five minutes. National Culture and Tissue Collection medium, diluted with Earle's buffered salt solution was used as the perfusate. The concentration of methotrexate in various samples was determined by high performance liquid chromatography, while antipyrine concentration was assayed by spectrophotometry. Transport and pharmacokinetic data of study and reference substances were computed using standard parameters.

RESULTS

Differential transport rate of methotrexate for 10, 25, 50, 75 and 90% efflux fractions in fetal venous effluent averaged 0.52, 1.30, 2.37, 3.57 and 4.43 minutes in 12 perfusions, representing 1.01 + 0.08, 1.03 + 0.06, 0.95 + 0.03, 0.93 + 0.03, 0.93 + 0.03 respectively times antipyrine reference value. Student's t-test showed varying differences between the control and study group data. Transport Fraction (TF) of methotrexate, expressed as fraction of the drug appearing in fetal vein, during study period of 5 minutes averaged 24.00 + 2.50% of bolus dose while antipyrine TF averaged 68.73 + 2.01% of injected bolus dose, representing 24.00 percent of reference marker value. Student's t-test showed methotrexate and reference marker TF values to be significantly different (p < 0.05). Pharmacokinetic parameters such as area under the curve, clearance, time for maximum response, absorption and elimination rates of study and reference substances showed varying differences.

CONCLUSIONS

We report for the first time that the transport of methotrexate from maternal to fetal circulation is not negligible in human placenta at term. It is reasonable to assume that a direct risk for the fetus from methotrexate use in pregnancy cannot be excluded, and caution is warranted when it is used in emergency clinical situations.

Biologics in dermatologic therapy - an update

Biologics are protein molecules which are used in various diseases to target the specific points in the immunopathogenesis of the diseases. The molecules are produced by recombinant DNA technology. The molecules bind to the specific targets without interfering wtih rest of the pathogenetic pathways. Therefore the so called 'immunosuppressives' have, although, a broader broader spectrum of action on immune system, their side-effects are also equally more. The biologics, because of their spefic action on the immune system, have very little side effects. The biologics which have revolutionized the treatment of various dermatologic diseases have been discussed here.

Cost-effectiveness and impact on quality of life of alefacept in the treatment of psoriasis

Although alefacept was the first biologic agent approved to treat psoriasis, it is used less frequently than other biologic therapies. Alefacept decreases the Psoriasis Area and Severity Index (PASI) score and enhances the quality of life of patients with psoriasis. Unlike other biologics, alefacept can also induce remission of psoriasis. If reports in Pubmed and the package insert are considered to be surrogates for side effects, alefacept appears to be safer than other biologics. Alefacept can be effective against psoriatic arthritis, especially in combination with methotrexate. The response of psoriatics to alefacept, however, is inconsistent and often incomplete. Alefacept also has the highest cost of any biologic agent as measured by patients achieving PASI-75 and cost per patient achieving Dermatology Life Quality Index Minimal Important Difference. Traditional systemic therapies such as spriatane, ciclosporine, as well as phototherapy and TNF-alpha, possess firmer and superior pharmacoeconomic foundations, although some of these apparent cost-benefit disadvantages may take into account the ability of alefacept to induce remission after cessation of treatment.

Alefacept: its safety profile, off-label uses, and potential as part of combination therapies for psoriasis

OBJECTIVES

To review literature regarding alefacept, a biologic therapy for psoriasis.

METHODS

A PubMed search using the term alefacept was done through December of 2006 and articles reviewed. Abstracts concerning alefacept presented at the meeting of the Annual meeting of the American Academy of Dermatology in 2004, 2005 and 2006 were reviewed. Attention was paid to alefacept's safety profile, off-label uses, and potential as part of combination therapy for psoriasis.

RESULTS

Alefacept is a very safe treatment for psoriasis alone or in conjunction with other therapies. It has been used, anecdotally, with some effect in diseases besides psoriasis.

CONCLUSIONS

The utility of checking CD4 counts while administering alefacept for 12 weeks is unclear. While no side effects have been linked to CD4 counts lower than 250/cc(3), due to the fact that in clinical trials alefacept was discontinued when the CD4 count was lower than 250/cc(3), the effect of administration of alefacept to patients with low CD4 counts is unknown. Alefacept appears to be the safest biologic therapy for the treatment of psoriasis, safety that has been borne out in patients who have received as many as nine courses of alefacept. Intramuscular alefacept's consistent ability to decrease the psoriasis area and severity index (PASI) scores in psoriatic patients is not as great as phototherapy, cyclosporine, methotrexate or tumor necrosis factor alpha blockers. Repeated courses of alefacept are best used in patients who have previously responded to the medication, so that patients who have found alefacept useful when grouped achieve higher and more consistent improvements of PASI scores with each successive course of alefacept. A test that would identify likely responders would greatly increase the utility of the medication. While reports assessing the combination of alefacept and narrow band ultraviolet B phototherapy have only studied small numbers of patients ( approximately 60), the combination of phototherapy and alefacept appears synergistic and extremely effective with studied patients achieving PASI 75 in more than 75% of cases and thus merits further study. Combinations of alefacept with etanercept, acitretin, and methotrexate have been used anecdotally but effectively to treat recalcitrant psoriasis. Reported effective off-label uses of alefacept include: generalized lichen planus, alopecia areata, steroid-resistant or steroid-dependent acute graft-versus-host disease, scleroderma, nail psoriasis, and palmoplantar psoriasis.