Disease activity and treatment efficacy using patient-level Psoriasis Area and Severity Index scores from tildrakizumab phase 3 clinical trials.

BACKGROUND: It is unclear whether primary efficacy outcomes in plaque psoriasis clinical trials represent residual disease during treatment. OBJECTIVES: To evaluate supplementing dichotomous efficacy with residual disease activity. METHODS: This post hoc analysis used pooled, patient-level data after tildrakizumab 100 mg (N = 616) or placebo (N = 309) treatment from reSURFACE 1/2 (NCT01722331/NCT01729754) phase 3 clinical trials of patients with moderate to severe plaque psoriasis. RESULTS: Median baseline Psoriasis Area and Severity Index (PASI) was 17.9 for patients receiving tildrakizumab 100 mg. At Week 12, median PASI was 2.9, whereas dichotomous PASI 90 response rate was 36.9%, and absolute PASI <5.0, <3.0, and <1.0 were 64.0%, 50.8%, and 23.3%, respectively. At Week 28, median PASI was 1.7, whereas PASI 90 response rate was 51.9%, and absolute PASI <5.0, <3.0, and <1.0 were 75.3%, 62.8%, and 38.0%, respectively. Dermatology Life Quality Index and PASI scores were correlated through Week 28 (r = 0.51, p ≤ .0001). CONCLUSIONS: Disease activity was more reliably estimated by PASI scores than percentage PASI improvement; this may partially explain efficacy disparities between clinical trials and practice. These results suggest supplementing dichotomous PASI improvement with PASI scores and consideration of patient treatment goals could facilitate clinical decisions.

Biosimilars: what the dermatologist should know.

Biosimilars are highly similar versions of approved branded biologics. In contrast to generics, which are identical copies of the originator medicines, biosimilars are considered unique but related molecules that differ from the originator reference product as well as from each other. Owing to the complexity of biologic medicines, such as therapeutic monoclonal antibodies, minor differences between biosimilars and the reference products are acceptable provided these differences do not result in any clinically meaningful differences in safety or efficacy. In addition, minor changes in structure and function may occur over time in originator biologic products as a result of alterations in production materials (e.g. cell lines), processes or conditions. The developmental process for biosimilars focuses on a 'totality of evidence' approach that emphasizes a stepwise investigational process, including comprehensive structural, functional, pharmacologic and clinical assessment for similarity. The goal of the phase 3 clinical development programme for a biosimilar is not to establish efficacy, per se, but to demonstrate that there are no clinically meaningful differences between the proposed biosimilar and the reference product. The requirement to show clinical similarity informs biosimilar study design, including the selection of the patient population, disease state (indication), study endpoints and statistical methods. Based on the clinical trial results in a representative patient population, results may be extrapolated to other indications provided scientific justification is demonstrated based on, among other things, similar mechanism of action in the extrapolated indications. This review presents the current state of knowledge with respect to biosimilars. We aim to provide the practising clinician with a working knowledge of biosimilars as well as provide some practical guidance on their use and potential benefits in treating dermatologic diseases.

Extension of ustekinumab maintenance dosing interval in moderate-to-severe psoriasis: results of a phase IIIb, randomized, double-blinded, active-controlled, multicentre study (PSTELLAR).

BACKGROUND: Phase III studies showed that some patients maintained response for ≥ 6 months following ustekinumab discontinuation. OBJECTIVES: To assess clinical responses with extended ustekinumab maintenance dosing intervals. METHODS: Adults with moderate-to-severe plaque psoriasis received ustekinumab at weeks 0, 4 and 16 during open-label treatment. Patients achieving a week-28 Physician's Global Assessment (PGA) score of cleared/minimal (PGA = 0/1) were randomized 1 : 4 to group 1 [approved every 12 weeks (q12 wk) maintenance] or group 2 (q12-24 wk; response-based dosing determined by time to loss of PGA = 0/1). Key end points included the number of visits with PGA = 0/1 (primary end point) and ≥ 75% improvement in Psoriasis Area and Severity Index (PASI 75) between weeks 88 and 112, and PGA/PASI responses between weeks 28 and 112. RESULTS: Overall, 378 patients achieved PGA = 0/1 at week 28 and were randomized to group 1 (n = 76) or group 2 (n = 302). Patients in group 1 had numerically greater mean numbers of visits with PGA = 0/1 than group 2 and also with PASI 75 from week 88 to 112. A higher proportion of patients in group 1 (55%) than group 2 (39%) had PGA = 0/1 at all seven visits from week 88 to 112. Maintenance of response was observed with dose-interval extension beyond q12 wk in a subset of patients. Extending the dosing interval did not affect antibody development or safety. CONCLUSIONS: Efficacy was better maintained among week-28 PGA responders randomized to continue q12 wk ustekinumab vs. extending maintenance dosing based on clinical response, although some patients maintained high levels of efficacy with up to q24 wk dosing.

Soft tissue filler and botulinum toxin treatment techniques.

A variety of non-invasive techniques have been utilized for the enhancement of cutaneous changes seen with photoaging. Such methods include chemical peels, microdermabrasion, ablative and nonablative lasers, and various rejuvenating light sources. However, the most widely used minimally invasive cosmetic procedures for the correction of undesired rhytides and enhance facial features through contouring and volumization are injections with botulinum toxin and soft tissue fillers. Their extensive long term safety and relative ease of procedural techniques have led to high satisfaction levels worldwide. Nonetheless, proper training of the fundamentals in injection technique, the choice of the appropriate candidate, and knowledge of potential adverse events are imperative to ensure an excellent and safe outcome.

Efficacy and safety results from a phase III, randomized controlled trial comparing the safety and efficacy of briakinumab with etanercept and placebo in patients with moderate to severe chronic plaque psoriasis.

BACKGROUND: The tumour necrosis factor-α antagonist etanercept and the interleukin (IL)-12/23p40 antagonist ustekinumab have been shown to be effective psoriasis therapies. The IL-12/23p40 antagonist briakinumab was shown to be effective psoriasis treatment in a phase II study. OBJECTIVES: To assess the efficacy, safety and tolerability of briakinumab compared with etanercept and placebo in patients with moderate to severe psoriasis. METHODS: Three hundred and fifty patients were enrolled in this phase III, 12-week study (M10-315, NCT00710580) and randomized in the following 2:2:1 ratio: 139 patients received 200 mg briakinumab at weeks 0 and 4 followed by 100 mg briakinumab at week 8; 139 patients received 50 mg of etanercept twice weekly 3-4 days apart at weeks 0-11; 72 patients received placebo injections matching active treatment. The co-primary efficacy endpoints were the proportion of patients achieving a Physician's Global Assessment (PGA) of 0/1 at week 12, and the proportion of patients achieving a Psoriasis Area and Severity Index (PASI) 75 response at week 12. RESULTS: Of the briakinumab-treated patients, 72·7% achieved a PGA of 0/1 at week 12 as compared with 29·5% of etanercept-treated patients and 4·2% of placebo-treated patients (P < 0·001, for both comparisons). Of the briakinumab-treated patients, 80·6% achieved a PASI 75 response at week 12 as compared with 39·6% of etanercept-treated and 6·9% of placebo-treated patients (P < 0·001, for both comparisons). Serious adverse events were reported in two (1·4%) briakinumab-treated patients, one (0·7%) etanercept-treated patient and two (2·8%) placebo-treated patients. CONCLUSIONS: In patients with moderate to severe psoriasis, briakinumab had superior efficacy to both placebo and etanercept at 12 weeks as administered in this study.

Effects of etanercept on C-reactive protein levels in psoriasis and psoriatic arthritis.

BACKGROUND: C-reactive protein (CRP), an inflammation biomarker, indicates cardiovascular risk and is elevated in psoriasis. The effect of etanercept on CRP in psoriasis has not been previously examined. OBJECTIVES: The primary objective was to examine the effect of etanercept on CRP levels from baseline to week 12 compared with placebo. Secondary objectives included assessment of baseline CRP and relationships between CRP and body mass index (BMI), statin drug use, and Psoriasis Area and Severity Index (PASI) scores. METHODS: A retrospective analysis was conducted of CRP levels from patients with psoriasis who participated in a randomized, double-blind, placebo-controlled, U.S. registrational study. Data were analysed separately if patients self-reported psoriatic arthritis. RESULTS: Baseline CRP levels were elevated in patients with psoriasis with and without psoriatic arthritis. CRP was significantly reduced in both groups after 12 weeks of etanercept treatment. Patients with psoriasis with psoriatic arthritis and patients with higher BMIs had higher median baseline CRP values and greater reduction of CRP values compared with those without psoriatic arthritis and those with lower BMIs. Etanercept lowered CRP levels in statin users and nonusers. Regression analyses revealed an association between baseline PASI score and baseline CRP independent of BMI in patients with psoriasis. CONCLUSIONS: Patients with moderate to severe plaque psoriasis, with or without psoriatic arthritis, have increased systemic inflammation demonstrated by elevated CRP levels. In psoriasis without psoriatic arthritis, skin disease activity is associated significantly with CRP elevation, independent of BMI, age and sex. Etanercept reduced CRP levels in all but the normal weight psoriasis group without psoriatic arthritis.

Psoriasis: immunopathogenesis and evolving immunomodulators and systemic therapies; U.S. experiences.

BACKGROUND: Psoriasis is a chronic inflammatory skin disorder that is presently without a permanent cure. Up to 40% of patients with psoriasis also develop psoriatic arthritis. The mainstay armamentarium to treat psoriasis systemically includes methotrexate, cyclosporin and oral retinoids, all with significant potential for toxicity and the need for close laboratory supervision. The although the exact mechanism of psoriasis is still unclear, the involvement of T-cell-mediated cytokine expression in the aetiology of psoriasis is becoming clearer. The goal of modern treatment is to target such immune responses that lead to the formation of psoriatic plaques and psoriatic arthritis using selective immunomodulating pharmacotherapy. The advantages of these biological agents are less toxic systemic side-effect profiles that will improve the quality of life in psoriatic patients. OBJECTIVES: This review article describes current and emerging selective immunotherapies and systemic therapies for the treatment of psoriasis, and will briefly discuss disease immunopathogenesis. METHODS: Literature review. RESULTS AND CONCLUSIONS: Given the role of the inflammatory immune responses in the pathogenesis of psoriasis, the goal of modern medicine and pharmacotherapy lies in the design and use of specific targets in cell-mediated immune reactions and the modulation of the expression of various inflammatory cytokines. The clinical evidence of efficacy of some of these new biological immunomodulatory agents from several U.S.-based research studies and clinical experiences is convincing.

Topical photodynamic therapy in clinical dermatology.

The growing incidence of cutaneous malignancies each year necessitates the development of new and more effective methods for both the diagnosis and the treatment of cancerous lesions, while assuring better cosmetic results and improving patient satisfaction. With that in mind, the use of topical photodynamic therapy (PDT) has been explored in the treatment as well as the diagnosis of various cutaneous malignancies. Using the intrinsic cellular haem biosynthetic pathway and principles of photoillumination, topical PDT carries the goal of selectively targeting abnormal cells, while preserving the normal surrounding structures. This paper will discuss the various applications and data on the use of topical PDT in dermatology.

Etanercept for severe psoriasis and psoriatic arthritis: observations on combination therapy.

BACKGROUND: The antitumour necrosis factor (TNF) activity of etanercept has been utilized to generate an important and novel treatment for rheumatoid arthritis. TNF has also been implicated in the pathogenesis of psoriasis. OBJECTIVES: To determine whether blockade of TNF activity by etanercept may provide an additional treatment option for patients with psoriasis. METHODS: In an uncontrolled trial, etanercept was added to the treatment regimen in six patients with severe recalcitrant psoriasis (three also with psoriatic arthritis) partially resistant to other ongoing systemic agents. RESULTS: In each case, the disease activity showed marked improvement on addition of etanercept therapy. No added toxicity was found with etanercept. CONCLUSIONS: Etanercept appears to be a promising immunomodulatory agent that can be used in combination therapy for the treatment of psoriasis, and a prospective controlled trial may be warranted.

A role for CD40-CD40 ligand interactions in the generation of type 1 cytokine responses in human leprosy.

The interaction of CD40 ligand (CD40L) expressed by activated T cells with CD40 on macrophages has been shown to be a potent stimulus for the production of IL-12, an obligate signal for generation of Th1 cytokine responses. The expression and interaction of CD40 and CD40L were investigated in human infectious disease using leprosy as a model. CD40 and CD40L mRNA and surface protein expression were predominant in skin lesions of resistant tuberculoid patients compared with the highly susceptible lepromatous group. IL-12 release from PBMC of tuberculoid patients stimulated with Mycobacterium leprae was partially inhibited by mAbs to CD40 or CD40L, correlating with Ag-induced up-regulation of CD40L on T cells. Cognate recognition of M. leprae Ag by a T cell clone derived from a tuberculoid lesion in the context of monocyte APC resulted in CD40L-CD40-dependent production of IL-12. In contrast, M. leprae-induced IL-12 production by PBMC from lepromatous patients was not dependent on CD40L-CD40 ligation, nor was CD40L up-regulated by M. leprae. Furthermore, IL-10, a cytokine predominant in lepromatous lesions, blocked the IFN-gamma up-regulation of CD40 on monocytes. These data suggest that T cell activation in situ by M. leprae in tuberculoid leprosy leads to local up-regulation of CD40L, which stimulates CD40-dependent induction of IL-12 in monocytes. The CD40-CD40L interaction, which is not evident in lepromatous leprosy, probably participates in the cell-mediated immune response to microbial pathogens.

Treatment of port wine stains using the pulsed-dye laser at 585 nm with the dynamic cooling device.

Port wine stains (PWS) are common vascular malformations appearing more frequently on the face and neck. One of the most prevalent treatment modalities for PWS is the pulsed-dye laser (PDL). The first generation PDL was limited to a 450 microseconds pulse width which was inadequate for the treatment of larger caliber vessels. Second generation PDLs have pulsed widths approximately three times longer (1.5 ms). This, along with the dynamic cooling device (DCD), which allows the safe use of higher fluences, should result in more clinical improvement in the treatment of PWS that were previously resistant or minimally responsive to first generation PDL treatment. We report a case of a 29-year-old white male with extensive PWS on the left face, left neck, and back, which displayed only mild changes with the first generation PDL. However, the use of the 1.5 ms PDL at 585 nm at high fluences in conjunction with the DCD resulted in marked improvement of the patient's PWS.

Treatment of pseudofolliculitis barbae with the diode laser.

Pseudofolliculitis barbae is a common skin disorder of the beard area that is characterized by the presence of inflammatory follicular papules due to terminal hair shafts re-entering the epidermis. Postinflammatory hyperpigmentation and scarring often occur with pseudofolliculitis barbae. Such skin changes can lead to cosmetic disfigurement and be of great concern to the patient. We report a case of pseudofolliculitis barbae and hirsutism with associated postinflammatory hyperpigmentation in an African-American woman who was effectively treated with the diode laser.

The function of a ribosomal frameshifting signal from human immunodeficiency virus-1 in Escherichia coli.

A 15-17 nucleotide sequence from the gag-pol ribosome frameshift site of HIV-1 directs analogous ribosomal frameshifting in Escherichia coli. Limitation for leucine, which is encoded precisely at the frameshift site, dramatically increased the frequency of leftward frameshifting. Limitation for phenylalanine or arginine, which are encoded just before and just after the frameshift, did not significantly affect frameshifting. Protein sequence analysis demonstrated the occurrence of two closely related frameshift mechanisms. In the first, ribosomes appear to bind leucyl-tRNA at the frameshift site and then slip leftward. This is the 'simultaneous slippage' mechanism. In the second, ribosomes appear to slip before binding aminoacyl-tRNA, and then bind phenylalanyl-tRNA, which is encoded in the left-shifted reading frame. This mechanism is identical to the 'overlapping reading' we have demonstrated at other bacterial frameshift sites. The HIV-1 sequence is prone to frame-shifting by both mechanisms in E. coli.

Absence of 2'-deoxy-GTP in adult brain tubulin.

Nerve growth factor can stimulate incorporation of 2'-deoxy-GTP into the non-exchangeable nucleotide sites in tubulin and cytoskeletal microtubules of PC12 pheochromocytoma cells and embryonic chick dorsal root ganglion neurons [J. M. Angelastro and D. L. Purich (1992) J. Biol. Chem. 267, 25685-25689]. We replaced and hydrolyzed exchangeable-site GTP and GDP in adult bovine brain tubulin by incubation with the non-hydrolyzable nucleotide analogue 5'-guanylyl-methylenediphosphonate and alkaline phosphatase, thereby allowing us to analyze the non-exchangeable guanine nucleotides for GTP and dGTP. HPLC analysis reveals no evidence of dGTP in adult tubulin, suggesting further that the appearance of dGTP in tubulin and microtubules may be a characteristic of recently dividing neurons in response to nerve growth factor.

Reduction in microtubule dynamics in vitro by brain microtubule-associated proteins and by a microtubule-associated protein-2 second repeated sequence analogue.

Microtubule-associated protein (MAP) binding to assembled microtubules (MTs) can be reduced by the addition of polyglutamate without significant MT depolymerization or interference with MT elongation reactions. Ensuing polymer length redistribution in MAP-depleted MTs occurs on a time scale characteristic of that observed with MAP-free MTs. The redistribution phase occurs even in the absence of mechanical shearing and without appreciable effects from end-to-end annealing, as indicated by the time course of incremental changes in polymer length and MT number concentration. We also observed higher rates of MT length redistribution when the [MAP]/[tubulin] ratio was decreased. Together, these results demonstrate that MT length redistribution rates are greatly influenced by MAP content, and the data are compatible with the dynamic instability model. We also found that a peptide analogue corresponding to the second repeated sequence in the MT-binding region of MAP-2 can also markedly retard MT length redistribution kinetics, a finding that accords with the ability of this peptide to promote tubulin polymerization in the absence of MAPs and to displace MAP-2 from MTs. These results provide further evidence that MAPs can modulate MT assembly/disassembly dynamics and that peptide analogues can mimic the action of intact MAPs without the need for three contiguous repeated sequences in the MT-binding region.

Microtubule-associated protein interactions with actin filaments: evidence for differential behavior of neuronal MAP-2 and tau in the presence of phosphatidyl-inositol.

Microtubule-associated protein (MAP) interactions with actin were investigated by falling-ball viscometry. At 1-2 microM MAP-2 or tau, we obtained a critical gelation concentration for actin of 0.1 mg/ml. In the presence of phosphatidyl-inositol, actin filament bundling was completely disrupted only when MAP-2 served as the cross-linker, whereas tau-induced bundling of actin was unaffected by phosphatidyl-inositol. This represents the first clear indication that MAP-2 and tau exhibit differential behavior in their interaction with cytoskeletal components.

Microtubule-associated protein autophosphorylation alters in vitro microtubule dynamic instability.

While phosphorylation of high-molecular-weight microtubule-associated proteins (MAPs) alters the assembly properties of microtubules in vitro, virtually nothing is known about the influence of MAP phosphorylation on the time-scale of microtubule polymer length redistribution. The latter has been used as an index of microtubule assembly/disassembly turnover as predicted by the dynamic instability model (Mitchison, T.M. and Kirschner, M.W. (1984) Nature 312, 237-242). We have now determined that under conditions leading to the incorporation of 8-10 mol phosphoryl groups per mol MAP-2 (and about 0.2 mol phosphoryl groups per mol MAP-1 and tau), we can reproducibly observe significant acceleration in the polymer length redistribution process in a manner consistent with greater microtubule dynamic instability. We have also found that MAP phosphorylation resulted in more extensive release of MAPs from microtubules as a function of increasing salt concentration. These results are consistent with a weakening of MAP-microtubule interactions upon phosphorylation.

Modulation of microtubule assembly and stability by phosphatidylinositol action on microtubule-associated protein-2.

Exposure of elongating (or assembled) bovine brain microtubules to phosphatidylinositol leads to polymerization arrest (or disassembly). The efficiency of phosphatidylinositol far exceeds the action of related phospholipids including phosphatidylethanolamine, phosphatidylcholine, 1,2-diacylglycerol, phosphatidylserine, phosphatidylglycerol, or phosphatidic acid. Phosphatidylinositol increases the apparent critical concentration for assembly, and the inhibitory effect of phosphatidylinositol on polymerization is reversed at higher concentrations of microtubule-associated proteins (MAP)s. Taxol- and glycerol-treated microtubules are insensitive to the destabilizing action of phosphatidylinositol; centrifugation and subsequent gel electrophoresis of such samples revealed that both MAP-2a and MAP-2b were selectively desorbed. Likewise, the desorption of MAP-2 was visualized by indirect immunofluorescence microscopy using primary antibodies directed toward tubulin and MAP-2. The instability of microtubules exposed to phosphatidylinositol appears to be related to the MAP-2 content.