Efalizumab, a reversible T-cell modulator for psoriasis

Tolerability, pharmacokinetics and pharmacodynamics of CMAB001, an anti-CD11a antibody, in Chinese healthy volunteers and psoriatic patients

AIM

To evaluate the pharmacokinetics (PK), pharmacodynamics (PD) and primary tolerability of an anti-CD11a monoclonal antibody (CMAB001) in Chinese healthy volunteers and psoriatic patients.

METHODS

Two open-label studies were conducted. One was a parallel-group, single-center, dose-escalation test, including 24 healthy adult volunteers from 18 to 45 years in age. All subjects randomly received a single subcutaneous injection dose of 0.5, 1.0 or 2.0 mg/kg. The other was a multiple-dose study: 10 adult psoriatic patients were administered weekly subcutaneous injections of 1.0 mg/kg for 7 weeks.

RESULTS

CMAB001 was well tolerated in the single- and multiple-dose studies. Slow absorption was observed in both studies. In the single-dose study, the concentration of CMAB001 reached its highest level 2 d later after the injection, and the C(max) increased in an approximate dose-proportionate manner, while the area under curve (AUC) showed much greater than dose-proportionate increase. In the multiple-dose study, the steady-state serum concentration level was attained following the 4th injection.

CONCLUSION

CMAB001 exhibited a nonlinear pharmacokinetic profile over the dose range from 0.5 to 2.0 mg/kg, and was well tolerated in healthy volunteers and psoriatic patients.

Use of biologic therapeutics in difficult-to-treat psoriasis

BACKGROUND

A need for improved psoriasis management drove the development of four biologicals now approved for use in moderate to severe psoriasis: alefacept, efalizumab, etanercept, and infliximab.

OBJECTIVE

This review compares the recommended and practical use of biologicals in "difficult-to-treat" psoriasis. Difficult-to-treat patients, a subpopulation of particular interest to caregivers and regulators, are those for whom conventional options are unavailable, contraindicated, intolerable, or ineffective.

CONCLUSIONS

Despite guidance recommending that biologicals be considered among first-line antipsoriasis treatments, formulary inclusion may be influenced by the biologicals' success in controlling difficult-to-treat psoriasis. Findings from the Clinical Experience Acquired with Raptiva (CLEAR) randomized controlled trial (RCT) established efalizumab's equal efficacy in difficult-to-treat and moderate to severe psoriasis. The CLEAR data were cited in support of a regulatory recommendation to include efalizumab in Canadian provincial formularies. For some other biologicals, evidence regarding efficacy in difficult-to-treat psoriasis remains equivocal. Additional RCTs are needed to define appropriate roles for specific biologicals in difficult-to-treat patients.

Onset of psoriatic arthritis in patients treated with efalizumab for moderate to severe psoriasis

OBJECTIVE

To investigate the nature of polyarthritis in patients with moderate to severe psoriasis undergoing treatment with efalizumab, a humanized anti-CD11a monoclonal antibody.

METHODS

In a multicenter study, we retrospectively analyzed patients who developed arthritis during treatment with efalizumab. The relationship between joint manifestations and psoriatic disease was addressed by using different classification criteria for psoriatic arthritis (PsA). The course of arthritis and its response to treatment were also investigated.

RESULTS

Sixteen patients developed de novo inflammatory rheumatic disease, with a mean delay of 15 weeks following the start of treatment, and with exclusive asymmetric peripheral monarthritis or oligoarthritis (8 patients), inflammatory spinal disease (1 patient), or both (7 patients), associated in some cases with enthesitis and dactylitis. All patients fulfilled at least 2 different sets of classification criteria for PsA. In most of them, an improvement in skin lesions was observed at the onset of PsA, as measured using the Psoriasis Area and Severity Index (mean score 24.88 before efalizumab versus 18.78 at the time of arthritis). Efalizumab treatment was stopped in 11 patients and was followed by the elimination of rheumatologic symptoms in 1 patient, while 8 patients required treatment with nonsteroidal antiinflammatory drugs with or without methotrexate, with 2 later being switched to tumor necrosis factor alpha inhibitors. Reintroduction of efalizumab (2 patients) was followed by a relapse of PsA.

CONCLUSION

This study questions the role of efalizumab in the induction of PsA. It also emphasizes the discrepancy between the courses of psoriatic skin and joint manifestations under treatment. Prospective case-control studies are needed to accurately investigate the impact of efalizumab on PsA.

Adhesion molecules in cutaneous immunity

Skin serves a vital role, providing protection from the broad array of pathogens present in our environment. In addition to the passive barrier functions of the skin, mammals have evolved a robust and versatile surveillance and rapid response system for recognition and elimination of invading organisms. This immune surveillance network directs the movement of immune cells, regulating homeostatic populations of immune cells in the skin, as well as recruitment to sites of inflammation. In this review, we discuss current understanding of the regulation and function of adhesion molecules in cutaneous immune surveillance and their relevance to the immunopathology of inflammatory skin disease.

A favourable benefit/risk ratio with efalizumab: a review of the clinical evidence

Moderate to severe plaque psoriasis has traditionally been treated with agents that have toxicities associated with long-term use. Many patients therefore cannot be treated safely, conveniently or effectively with traditional therapies. Recent phase 3 clinical trials for efalizumab, a biological agent targeted specifically at the T-cell-based pathology of psoriasis, have demonstrated its short- and long-term efficacy and safety for the treatment of psoriasis. This article reviews results from 12-week, six-month, and three-year trials, focusing on the drug's safety, efficacy, and therapeutic response time, as well as the phenomenon of rebound in non-responding patients. Efalizumab emerges as an important addition to the dermatological pharmacopeia for the long-term treatment of psoriasis.

Efalizumab: integrating a new biologic agent into the long-term management of moderate to severe plaque psoriasis

Efalizumab, one of a new generation of biological agents, has been approved for use in moderate to severe psoriasis in over 35 countries including Canada. It may hold the promise of a new level of safe, long-term disease control for psoriasis patients, who have had few adequate options to date. Dermatologists and other caregivers may require some background regarding the mechanisms of action and the optimal use of this drug before integrating it into their standard repertoire of treatment. The present supplement discusses efalizumab's biological basis and reviews its clinical safety and efficacy. The salient differences amongst the various biologicals, with regard to safety, efficacy and convenience, are also considered. The supplement concludes with a practical guide to initiating and maintaining patients on efalizumab treatment.

Strategies for optimizing treatment with efalizumab in moderate to severe psoriasis

With the advent of biological therapies for the treatment of plaque psoriasis, guidance on the usage of these new agents has become necessary. One such agent, efalizumab, a humanized recombinant monoclonal IgG(1) antibody developed to target T-cell-mediated inflammation, provides rapid and sustained efficacy for many psoriasis patients. This article explores the pretreatment, initiation, and treatment phases with efalizumab therapy. In the pretreatment phase, physicians need to assess patients' disease state and educate them about the course of efalizumab treatment. Prior to initiation, physicians need to establish stable disease, ensure an adequate transition or washout of any prior psoriasis therapeutics, and obtain baseline platelet counts. After initiating treatment, both physician and patient must participate in disease monitoring. Patients responding favourably may receive continuous treatment. Those who do not respond to the drug or who experience adverse events should be managed appropriately in order to continue therapy or be transitioned onto another agent. A growing body of clinical evidence, as well as experience from clinical investigators, has provided much insight into the management strategies for patients undergoing treatment with efalizumab.