All patients discontinued all other antipsoriatic therapies at least 28 days prior to beginning the trial. They were assessed by blinded investigators at two different medical centers on day 56 (8 weeks) and day 112 (16 weeks). Investigators used Physician's Global Assessment (PGA) scores, Psoriasis Area and Severity Index (PASI), body surface area measurement, and patient-rated itch severity in their assessments.
In the intent-to-treat analysis, patients receiving the XP-828L formula showed a statistically significant reduction in PGA scores from a mean of 3.05 at baseline to 2.79 after 8 weeks. There was no significant difference in the placebo-treated patients, whose scores went from 3.12 to 3.05. Exclusion of the 15 patients who did not complete the protocol did not change the finding in any way.
There was a trend toward greater improvement in the PASI scores among patients receiving the whey proteins, but the differences between the two groups were not significant (J. Cutan. Med. Surg. 2006;10:241–8).
There were no major differences on any of the assessment scales at 16 weeks, following the period in which placebo-treated patients were switched to the 10-g daily dose of the whey proteins. Their PGA scores improved more or less to the level seen in the patients treated with the lower dose, who generally maintained their improvements but did not obtain any additional benefit after the first 8 weeks.
The investigators concluded that “a period of 56 days of treatment with 5 g/day of XP-828L is sufficient to induce and maintain a clinical improvement of mild to moderate psoriasis.” Though it is clearly no competition for the biologics or other advanced drug therapies, the whey protein formulation can reduce symptoms and severity in many cases.
Moreover, it can do so with minimal risk of adverse effects. There were no clinically apparent side effects from the whey proteins at either the 5-g or 10-g daily dose, and there were no changes in creatinine, total bilirubin, transaminase enzymes or other biochemical markers.
The precise mechanisms underlying the whey protein effects are not entirely clear, but Dr. Poulin noted that whey contains β-lactoglobulin, α-lactalbumin, lactoferrin, immunoglobulins, and growth factors that have immuno- modulatory effects.
In vitro work with XP-828L shows that the compound can inhibit production of Th1 cell cytokines, especially IFN-γ and IL-2, which would presumably have a down-regulatory effect on T-cell-mediated disorders like psoriasis and possibly other chronic inflammatory diseases like irritable bowel syndrome, ulcerative colitis, and atopic dermatitis. The formula also contains high levels of transforming growth factor (TGF)-β2.
“Additional studies are needed to evaluate the potential of XP-828L to complement traditional treatments for psoriasis. From its safety and efficacy profiles, a natural product such as XP-828L could be a good addition to traditional therapies [for psoriasis,” they wrote.
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