The effect of bevucizumab, an antivascular endothelial growth factor over nasal mucosa and nasal polyposis

Objective: The prevalence of nasal polyposis has been reported as one to four per cent. Its etiopathogenesis has not been fully understood. In the tissue culture studies, the expression of vascular endothelial growth factor (VEGF) has been demonstrated to increase in nasal polyposis. In general, VEGF functions by inducing angiogenesis end increasing capillary permeability. Despite trial of various methods, nasal polyps very frequently recur. Anti-VEGF has been introduced in the treatment of hereditary hemorrhagic telengiectasia that is characterized with persistent epistaxis, in recent years. The hypothesis of our study is that anti-VEGF would prevent development of new nasal polyps and growth of the existing ones, by inhibiting neo-vascularization. This hypothesis has been tested through immune deficient experimental animal (mice) model. Studying the efficacy of the anti-VEGF over nasal polyposis, we also aimed to investigate its adverse effects over the nasal mucosa. Method: The nasal polyp tissue samples harvested from the patients during the operations have been implanted into the immun defficient Nude CD-1 mice. Eight-mice 1st group have been taken as the control group. Eight-mice 2nd group have been given parenteral (intraperitoneal) bevacizumab, an anti-VEGF drug. A 3rd group eight-mice group has been given topical bevacizumab through Alzet pump, which enables direct administration of the drug over the implanted polyp tissue. The last, 4th group eight mice have been administered bevacizumab over the implanted nasal mucosa samples. Results: The results of the study have revealed that through immune deficient mice model, bevacizumab, an antagonist of VEGF, that has been demonstrated to play an important role in the pathogenesis of nasal polyposis has regressed xenografted nasal polyp tissues, in comparison to control tissues at statistically significant level. This effect has been found more pronounced by the parenteral use of the drug than its topical use. It is very likely that this is due to the inhibitory effect of bevacizumab over neovascularization in the nasal mucosa and nasal polyp tissue, and related tissue-stabilizing effect. Conclusion: The results of the study interpreted as the anti-VEGF bevacizumab deserves to be tried in the treatment of NP, a persistent and recurring disease, initially in its topical form and these results may open a new venue in the treatment of the disease. The other result of our study has also confirmed that immun-deficient mice model can be successfully used in the investigation of effects and side effects of newly developed drugs.