Psoriasis is a common, chronic and incurable condition that affects 5.7 million people in Europe. [i] The symptoms of the disease have a serious negative impact on patients' quality of life and the associated increased risk of comorbidities can ultimately result in reduced life expectancy.
There is a significant unmet clinical need for efficacious treatments that can be used safely in the long-term to effectively manage this life long condition and help prevent the damaging effects of comorbidities that result from poorly controlled psoriasis.
As of April 2007, more than 40,000 patients have received Raptiva® corresponding to a cumulative clinical experience of >28,000 patient-years of exposure and data continues to be collected for future investigation. These data, collected over a decade from experience during clinical development and post-marketing surveillance, were gathered and a safety review carried out. Results demonstrate Raptiva®'s favourable safety profile and show that rates of known adverse events have remained stable throughout the post-marketing period.
In addition to this positive safety data; results of the longest continuous study of any biological therapy for psoriasis treatment were published in the British Journal of Dermatology in May 2008. This study, Efalizumab: results of a 3-year continuous dosing study for the long-term control of psoriasis, [ii] clearly demonstrates Raptiva®'s long term efficacy. Results show that Raptiva® is effective for many patients; at 3 years of treatment 73% of responding patients achieved a PASI 75 response and 40% of patients even achieved and maintained a PASI 90 response ("as-treated" analysis). Clinical benefit of Raptiva® continuously improved over the first 18 months and was maintained during 3 years of continuous therapy. The safety profile was stable, with no new or no increase in common adverse events over the 3 year period.ii
Professor Kim Papp, Founder and President of Probity Medical Research said "Chronic inflammatory systemic diseases like psoriasis require long-term treatment and care. These data are very encouraging and provide support for efalizumab as an appropriate treatment option for many patients with moderate to severe plaque psoriasis."
Recent research has shown the chronic inflammation which results in the symptoms on the skin of psoriasis patients also has a significant effect on organ systems beneath the skin. Cytokines may act as inflammatory mediators and sustained inflammation may contribute to endothelial dysfunction and accelerated atherosclerosis. [iii] Psoriasis patients are also at increased risk of other associated comorbidities including obesity, diabetes and CVD. Those that have been treated as an in-patient at least once have a 50% increased risk of cardiovascular death compared to the general population. i Of note, psoriasis decreases life expectancy by up to 10 years.i A trend which is greater with earlier onset of disease (<25 years). i
"Patients with moderate to severe psoriasis require life-long management of their disease. Recent findings around reduced life expectancy and comorbidities suggest that there should be shift towards treating patients earlier and more aggressively to control the chronic systemic inflammation. This requires a treatment that is convenient and appropriate for continuous use with a favourable safety profile over the long-term. Raptiva®, which is a T cell modulator, has a unique and targeted mode of action (MoA) which provides enduring disease reduction up to 3 years." Said Professor Mehmet Ali Gurer, EADV Spring Symposium Chairman and Professor of Dermatology, Gazi University Medical School, Ankara, Turkey.
Psoriasis is a T-cell mediated disease, which occurs due to chronic inflammation causing skin cells to grow abnormally, resulting in thick, red, scaly, inflamed patches. Plaque psoriasis, the most common form of the disease is characterised by inflamed patches of skin ("lesions") topped with silvery white scales. Psoriasis can be limited to a few spots or involve extensive areas of the body, appearing most commonly on the knees, elbows, trunk, and scalp. Although it is highly visible, psoriasis is not a contagious disease. While there are a number of medications that may help control the symptoms of psoriasis, there currently is no known permanent cure.
Unmet Need in Plaque Psoriasis
Despite the many traditional treatments available for psoriasis (topicals, phototherapy, systemics), the adverse events or inadequate efficacy of current therapies [iv] make psoriasis therapy a start / stop cycle of intermittent and episodic treatment for many patients, which can lead to recurring cycles of disease relapse and remission. Innovations in biotechnology have the potential to offer greater safety by building targeted drugs, such as Raptiva®, that interfere with specific targets in the pathogenesis of psoriasis. [v]
Raptiva® is a targeted biological therapy in the form of a humanised anti-CD11a monoclonal antibody. It has been uniquely engineered to target T-cells to inhibit or modify their activity resulting in a therapeutic benefit in psoriasis. The drug works by blocking the activity of CD11a, which is part of a cell adhesion molecule expressed on the surface of T-cells, thereby targeting three key processes in the cascade of events that lead to psoriasis:
1. Binding of T-cells through interactions with adhesion molecules on the endothelial cell surface.iv, v
2. Migration of T-cells into the skin.iv, v
3. Activation of T-cells,iv, v all of which may be linked to the abnormal growth of skin cells and the painful, elevated scaly patches of skin (lesions) typical among psoriasis sufferers.
Raptiva® received EU approval on 20th September 2004 for the 'Treatment of adult patients with moderate to severe chronic plaque psoriasis who have failed to respond to, or who have a contraindication to, or are intolerant to other systemic therapies including ciclosporin, methotrexate and PUVA'.
[i] Gulliver W. Poster presented at the American Academy of Dermatology (AAD) Meeting, Feb 2007
[ii] Leonardi C, Menter A, Caro I et al, Efalizumab: Results of a three-year continuous dosing study for the long term control of psoriasis. BJD 2008;158:1107-1116.
[iii] Ferrante A, et al. Abstract #OP0106 EULAR 2005; Hannawi et al., Abstr. 364.
[iv] Cather JC, Menter A. Modulating T cell responses for the treatment of psoriasis: a focus on efalizumab. Expert Opin Biol Ther 2003;3:361-370.
[v] Jullien et al. T-cell modulation for the Treatment of Chronic Plaque Psoriasis with Efalizumab (Raptiva®): Mechanisms of Action. Dermatology 2004;208:297-306
European Academy of Dermatology and Venereology