Impact of efalizumab on psoriasis-specific patient-reported outcomes: results from three randomized, placebo-controlled clinical trials of moderate to severe plaque psoriasis

Journal of Drugs in Dermatology, Jan-Feb, 2004 by Alan Menter, Mark Kosinski, Brian W. Bresnahan, Kim A. Papp, John E. Ware

The results of the burden analyses suggest that moderate to severe psoriasis may have serious productivity and economic consequences. First, nearly 20% of the patients in this study reported that their skin had greatly affected their ability to work, which may translate into lost wages to the employee and reduced productivity to the employer. This rate is slightly lower than that previously reported for patients with severe psoriasis (13); however, this study also included patients with moderate psoriasis. Second, more than one half of the patients indicated being greatly bothered by 7 of 8 psoriasis symptoms. This unmet clinical need for effective treatment contributes to the high cost of outpatient care for psoriasis, which in 1993 was estimated to be in the billions of dollars (41). Furthermore, in addition to the health care resources utilized to treat the disease itself, it is likely that individuals with moderate to severe psoriasis will require additional health resources to treat disease-associated anxiety, depression, and functional impairment as these aspects of their disease become better understood (11,15,42).

All patient-reported outcome measures used in this study were skin- or psoriasis-specific. While these instruments provided critical insights into understanding the burden of psoriasis on the patient's life, they do not permit comparisons outside of the realm of psoriasis or other dermatological conditions. It would have been useful to characterize the extent of the burden of moderate to severe psoriasis on patient functioning and well-being in the context of population norms and disease benchmarks. A more comprehensive assessment of disease-related morbidity requires the use of "generic" measures of health and quality of life, allowing comparison of disease burden across different diseases and populations. In one such study, the investigators found psoriasis to have an equal or larger impact on physical functioning and mental health than other diseases with well-known morbidity, such as heart disease, diabetes, arthritis, cancer, and depression (15). In another study, patients with psoriasis were shown to have considerably lower general health status compared to population norms (40). Although other studies using generic measures of health-related quality of life found the burden of psoriasis have a less pronounced impact, these studies included patients with milder forms of psoriasis (12,43).

Efalizumab treatment significantly improved the patient's dermatology-related quality of life and reduced the impact of itch and other psoriasis symptoms. Score changes on each of the summary indices of the DLQI, PSA, and Itch measures among efalizumab-treated patients were nearly as large as a full standard deviation, or in the large effect size range (37). Furthermore, patients who received efalizumab were 3 to 4 times more likely than placebo-treated patients to meet statistically and clinically defined response criteria established for each patient-based measure. This study also showed that the improvements in dermatology-related quality of life and symptom severity observed during the first treatment phase were maintained throughout the extended treatment phase of 24 weeks, and furthermore patients first randomized to placebo who subsequently received efalizumab showed significant improvement in dermatology-related quality of life and symptom severity, mirroring that observed for the efalizumab group during the first treatment phase.