Various approaches are currently used to treat and manage psoriasis, and biological treatments are often the latest approaches. All biological treatments have major side effects as they are given systemically via injections. One of the latest biological treatments for psoriasis, one which has shown great efficacy with fewer side effects, is Secukinumab. Secukinumab is an anti-IL17 antibody that works by stopping the action of IL17, a cytokine that is known to have a major role in the pathogenesis of psoriasis. This work is based on the development of a new way to commence drug therapy to reduce the side effects of the treatment. Our work is based on the studies of the genotoxicity of the drug Secukinumab in its bulk and liposome form using comet and micronucleus assays on lymphocytes. The results from both assays have illustrated the safety of the drug and demonstrated the reduction of the DNA damage induced in both healthy individuals and patients with psoriasis. Secukinumab significantly decreases-H2O2 induced damage and efficiently attenuates its adverse effects both in the comet (p<0.0001) and micronucleus assays (p<0.01). The two concentrations of Secukinumab used (2.1 and 2.8μg/ml) efficiently decreased H2O2-induced DNA damage in both groups to nearly the level of the negative control. Overall, Secukinumab reveals protective and anti-genotoxic effects by demonstrating its potential in reducing DNA damage caused by oxidative stress and by not inducing any further damage in the lymphocytes of either healthy individuals or patients. Liposomes are highly versatile which have been proven efficient for therapy and research applications. The discovery of new therapies in the treatment of psoriasis is a considerable challenge and is now a necessity. Our study was the first one to determine the genotoxicity of various concentrations of the drug in the lymphocytes of psoriasis patients compared to healthy individuals. In the MTT assay, the data showed a decrease in % cell survival rates after exposure to different concentrations of Secukinumab. Also, the results demonstrated no statistically significant differences on confounding factors such as ethnicity, smoking, drinking habits, gender and age among psoriasis patient and healthy controls. The regulation of gene expression levels of IL-17, IL-22 and RORC were assessed after treatment with Secukinumab in the bulk and liposome form via RT-PCR analysis. Secukinumab bulk (2.1μg/ml) treatment significantly down-regulated gene expression of IL-17, IL22 and RORC to 0.46-fold, 0.47-fold and 0.5-fold, respectively. However, Secukinumab liposome (2.1μg/ml) only decreased the expression of IL-17 and IL-22 significantly, by 0.46-fold and 0.53-fold, respectively. On the other hand, studying the expression of P53 and P21 using qPCR revealed that Secukinumab bulk and liposome has no effect on the expression of these genes in lymphocytes from healthy individuals and psoriasis patients. Western blotting was used to investigate the effect of Secukinumab in both forms on protein expression levels IL-17, IL-22 and RORC. Analysis of the results showed that Secukinumab bulk and liposome had no significant effect on expression levels of any of these proteins in lymphocytes derived from healthy individuals. However, there was a statistically significant down-regulation observed in the protein expression levels of IL-17, IL-22 and RORC in lymphocytes obtained from the psoriasis patients, confirming the sensitivity of the compromised lymphocytes from patient group to Secukinumab treatment. With Secukinumab (bulk form) administration, a 0.5-fold decrease was observed in IL-17, 0.59-fold decrease in IL-22, and a 0.6-fold decrease in RORC expression. However, liposome form reduced their levels to 0.47–fold, 0.5-fold and 0.47–fold, respectively, when compared to the control group. While it had no significant effect on expression of P53 and P21 proteins in lymphocytes from healthy individuals and psoriasis patients and there was no difference observed in their regulation. In conclusion, the use of Secukinumab liposome as topical drug delivery system may be suitable replacement for improving the drug bioavailability and its side effects. / Libyan Cultural Attaché and Libyan embassy