Current concepts and review of alefacept in the treatment of psoriasis

Combining Biologics in Inflammatory Bowel Disease and Other Immune Mediated Inflammatory Disorders

Current therapies used in the treatment of inflammatory bowel disease (IBD) are not effective in all patients. Biologic agents result in approximately 40% remission rates at 1 year in selected populations, prompting a growing interest in combining biologic therapy to improve outcomes. There are limited published data regarding the efficacy and safety of combination targeted therapy in IBD specifically, which include only 1 exploratory randomized control trial and 3 case reports or series. This review evaluates the published literature regarding this therapeutic paradigm in IBD and its extensive utilization in the treatment of other immune-mediated inflammatory disorders. The combination of biologic therapies demonstrates variable degrees of efficacy and highlights some safety concerns, depending upon the agents used and the disease state treated. A trial (Clinical Trials.gov Identifier: NCT02764762) combining vedolizumab and adalimumab is currently underway evaluating the effectiveness and safety of this approach in patients with Crohn's disease, which should provide further insight into this treatment concept. While combination biologic therapy is an attractive strategy, the lack of consistent superior efficacy as well as safety concerns militates the need for further trials prior to its general application in IBD.

A review of acitretin for the treatment of psoriasis

BACKGROUND

Acitretin is an oral retinoid that is approved for the treatment of psoriasis. It is unique compared to other systemic therapies for psoriasis such as methotrexate and cyclosporine in that it is not immunosuppressive. It is, therefore, safe for use in psoriasis patients with a history of chronic infection such as HIV, hepatitis B, hepatitis C or malignancy who have a contraindication to systemic immunosuppressive therapy and require systemic therapy because topical therapy is inadequate and they are unable to commit to phototherapy. Acitretin is one of the treatments of choice for pustular psoriasis. Even though acitretin is less effective as a monotherapy for chronic plaque psoriasis, combination therapy with other agents, especially UVB or psoralen plus UVA phototherapy, can enhance efficacy.

OBJECTIVE

To provide an updated review of the safety and efficacy of acitretin in the treatment for psoriasis.

METHODS

Literature review of journal articles from 2008 to 2009 since the last review of acitretin evaluated medical literature from 2005 to 2008.

RESULTS/CONCLUSION

Acitretin is an effective systemic therapy for psoriasis and is generally well tolerated at low doses for long-term use. If monotherapy with acitretin is inadequate, it can be used in combination with other treatments, particularly UVB phototherapy, to increase efficacy.

Emerging drugs for psoriasis

BACKGROUND

Psoriasis is a relatively common, chronic and disabling skin disease, due to a disturbed proliferation and differentiation of keratinocytes, accompanied by vascular alterations and infiltration of inflammatory cells with a local T(H)1-type cytokine immune response. There is no cure, but several treatment options are available.

OBJECTIVE

The treatment of psoriasis is far from being satisfactory, due to the impractical modalities of topical treatment and the suboptimal safety profile of the systemic treatments available. In the last few years, parallel to an improved understanding of the disease pathogenesis, there has been a boosting of research in new agents for the treatment of psoriasis. These new agents are the focus of this paper.

METHODS

After a short review of the treatment options already available (mainly based on the available systematic reviews), we focused on agents that are still in clinical development (Phase I - III) and have not yet entered the market. For the purpose of this study, we systematically searched the main registries of ongoing trials up to August 2008.

RESULTS/CONCLUSION

The field is very dynamic, with both immunopharmacology of recombinant DNA techniques and more traditional small-molecule pharmacology actively delivering new agents. With the increasing number of new options, there is a need for research systems that enable to effectively collect long-term safety data on treated patients.

Efalizumab therapy for psoriasis in patients with inadequate responses to etanercept

Efalizumab is a recombinant humanized monoclonal antibody approved for the treatment of adult patients with moderate-to-severe chronic plaque psoriasis. We present six cases of favorable response to efalizumab therapy in patients with psoriasis who demonstrated inadequate response or who were non-responders to treatment with etanercept, a tumor necrosis factor-alpha-binding fusion protein. The subsequent response of these patients suggests that efalizumab may be a viable treatment option for patients with psoriasis who respond poorly to etanercept.

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.

Current and future management of psoriasis

Management of psoriasis begins with identification of the extent of cutaneous disease. However, a holistic, contractual approach to treatment is encouraged, with particular reference to psychosocial disability and quality-of-life issues. The presence of psoriasis on palms, soles, body folds, genitals, face, or nails, and concomitant joint disease, are also important when considering treatment options. An evidence-based approach is essential in delineating differences between the many available treatments. However, archaic approaches, especially combinational ones, are routinely used by some clinicians, with inadequate prospective or comparative evidence. Treatments currently available are: topical agents used predominantly for mild disease and for recalcitrant lesions in more severe disease; phototherapy for moderate disease; and systemic agents including photochemotherapy, oral agents, and newer injectable biological agents, which have revolutionised the management of severe psoriasis. Other innovative treatments are undergoing clinical studies, with the aim of maintaining safe, long-term control of the condition.

Novel Insight into the Agonistic Mechanism of Alefacept In Vivo: Differentially Expressed Genes May Serve as Biomarkers of Response in Psoriasis Patients

Alefacept is an LFA3-Ig fusion protein that binds to CD2 and is thought to inhibit T cell activation by antagonism of CD2 signaling or by lysis of CD2(+) cells. Alefacept is potential future therapeutic for organ transplant recipients or graft-vs-host disease and is an approved therapeutic for psoriasis vulgaris, which is a T cell-mediated inflammatory disease. However, alefacept improves psoriasis in only approximately 50% of patients treated for 12 wk. We studied the immunologic effects of alefacept in a group of psoriasis patients during treatment. We found that T cells, especially CD8(+) T cells, were rapidly decreased in the peripheral circulation. Decreases in circulating T cells were not associated with induced apoptosis. Unexpectedly, in addition to suppression of inflammatory genes, we found a marked induction of mRNAs for STAT1, IL-8, and monokine induced by IFN-gamma during the first day of treatment in PBMC. We confirmed the agonistic effects of alefacept in PBMC in vitro, which were similar to CD3/CD28 ligation on T cells. These data establish that alefacept activates gene expression programs in leukocytes and suggest that its therapeutic action may be as a mixed agonist/antagonist. Furthermore, responding patients to alefacept treatment show unique patterns of gene modulation. Whereas alefacept down-regulated TCRs CD3D and CD2 in responders, nonresponders reveal a higher expression of T cell activation genes such as CD69 in pretreatment PBMC. These finding suggest a potential basis for categorizing responders vs nonresponders at an early time point in treatment or before treatment of a broad range of proinflammatory diseases. This study 1) establishes alefacept as a novel CD2 agonist molecule for induction of leukocyte activation genes (prior work proposed its mechanism as a CD2 antagonist) and 2) that differential activation of genes may categorize clinical responders to this agent, critical for cost-effective use of this drug.

Immunobiologics in the treatment of psoriasis

The pathogenesis of various inflammatory cutaneous diseases such as psoriasis, atopic dermatitis and mycosis fungoides relies greatly on the abnormal function of T cells. Fundamental knowledge of the role of T cells in the cutaneous immune response has led to the development and production of biologic molecules designed to block T cell function at various steps, specifically activation (i.e. alefacept, efalizumab), trafficking into inflamed skin (i.e. efalizumab) and effector function under cytokine control (i.e. etanercept, infliximab, adalimumab, and anti-IL-12 antibody). We review the immune abnormalities and the role of T cells in psoriasis, and the recent biologic therapies, which share the common mission to hinder T cell activity in inflammatory diseases. An advantage from the preciseness of these biologic therapies is the potential limit of non-specific and potentially devastating organ toxicity, which commonly plagues other systemic therapies.

Enhanced Fc-dependent cellular cytotoxicity of Fc fusion proteins derived from TNF receptor II and LFA-3 by fucose removal from Asn-linked oligosaccharides

Fucose removal from complex-type oligosaccharide of human IgGs results in a major enhancement of Fc-dependent cellular cytotoxicity. The aim of this study was to determine the effect of fucose removal on the effector function of another class of clinically important molecules that can effect cellular cytotoxicity, Fc fusion proteins. The receptors chosen for study were TNF receptor II and LFA-3, both of which have therapeutic significance. The fucosylated versions of these fusion proteins were produced in unmodified CHO cells, whereas the nonfucosylated counterparts were produced in CHO cells with alpha-1,6-fucosyltransferase, an enzyme required for fucosylation, knocked-out. Whilst binding activity of TNFRII-Fc and LFA-3-Fc were unchanged by fucose-removal, nonfucosylated Fc fusion proteins exhibited significantly higher Fc receptor gammaIIIa-binding and increased Fc-mediated cytotoxicity on target cells compared to fucosylated counterparts. Notably, in case of TNFRII-Fc, only the nonfucosylated protein exhibited potent Fc dependent cytotoxicity to transmembrane TNF-alpha expressing cells. These results prove that enhancement of Fc dependent cellular cytotoxicity by fucose-removal is effective in not only whole IgG but also Fc fusion proteins, and thus widens the potential of Fc-fusion proteins as therapeutic candidates.

Use of alefacept and etanercept in 3 patients whose psoriasis failed to respond to etanercept

This article reports on the combined use of alefacept and etanercept in 3 patients whose psoriasis failed to respond adequately to etanercept. All patients maintained improvement for at least 8 weeks after completing 12 weeks of alefacept. No adverse events or infections were reported, and CD4+ T-cell counts remained above normal limits.

An integrated analysis of thirteen trials summarizing the long-term safety of alefacept in psoriasis patients who have received up to nine courses of therapy

BACKGROUND

Information on longer-term safety and tolerability is needed to confidently prescribe alefacept therapy for chronic plaque psoriasis beyond 1 or 2 courses.

OBJECTIVE

The aim of this work was to further examine the safety profile of alefacept by integrating data from clinical trials involving patients with chronic plaque psoriasis who received up to 9 courses of therapy over a 5-year period.

METHODS

Data from 13 clinical trials conducted in patients with plaque psoriasis were integrated because they had similar inclusion/exclusion criteria and assessments. Patients who enrolled in the analyzed trials were aged > or =15 years with chronic plaque psoriasis for > or =12 months that involved > or =10% of body surface area, and CD4+ T lymphocyte counts above the lower limit of normal (>404 cells/microL). The incidences of adverse events (AEs), serious AEs, discontinuations for AEs, infections, serious infections, malignancies, and anti-alefacept antibodies were summarized for each course of alefacept. The incidence of infections was stratified according to CD4+ T lymphocyte counts (<250 cells/microL vs > or =250 cells/microL).

RESULTS

Data from 13 clinical trials of alefacept were integrated and summarized (multicenter, randomized, double-blind studies, n = 6; multicenter, open-label studies, n = 5; other, n = 2). The analyzed population (n = 1869) included 1291 (69.1%) men and 578 (30.9%) women, between the ages of 15 and 84 years (mean, 44.8 years), of whom 1648 (88.2%) were white. Weights ranged from 40 kg to 206 kg (mean, 90.0 kg). A total of 1369 of these patients had been included in a previous analysis. Among the most commonly reported AEs in each treatment course were headache (0%-14.2%), nasopharyngitis (7.7%-25.0%), influenza (0%-8.1%), upper respiratory tract infection (0%-12.5%), and pruritus (0%-7.5%). The rates of discontinuations due to AEs (0%-4.8%), serious AEs (0%-4.8%), serious infections (0%-0.9%), or malignancies (0%-4.8%) did not appear to increase with repeated exposure. Fewer than 1 % of patients in each course developed a serious infection. No opportunistic infections or infection-related deaths were reported. The incidence of infections appeared to be unrelated to CD4+ T lymphocyte counts. Fewer than 2.5% of patients tested positive for anti-alefacept antibodies during any course of therapy.

CONCLUSIONS

This integrated analysis of data from 13 trials with 1869 patients supports the safety and tolerability of alefacept for longer-term treatment of psoriasis.

Overview of biologic agents in medicine and dermatology

Three agents have recently been approved by the Food and Drug Administration for the treatment of chronic plaque psoriasis: alefacept, efalizumab, and etanercept. The field of dermatology has now entered a new era, joining other disciplines of medicine that have been using biologic agents for decades. These new therapies offer psoriatic patients the potential for safe and effective long-term management of this disease. This article reviews how an increased understanding of the pathophysiology of psoriasis led to the development of these products.