Cosentyx is a biologic drug used to treat various autoimmune diseases such as psoriasis and psoriatic arthritis. It works by blocking the activity of a protein called interleukin-17A (IL-17A), which is responsible for causing inflammation in the body.

According to Drug Patent Watch [1], the patent for Cosentyx is set to expire in 2034. This suggests that there have been no significant changes in the drug's effectiveness that would warrant a new patent.

However, a study published in the Journal of Clinical Medicine [3] found that some patients may develop resistance to Cosentyx over time. The study followed 56 patients with psoriasis who were treated with Cosentyx for at least 6 months. Of these patients, 16 (29%) experienced a loss of response to the drug. The study suggests that this may be due to the development of neutralizing antibodies, which can reduce the effectiveness of the drug.

Despite this, a review published in Medical News Today [2] suggests that Cosentyx is still an effective treatment for psoriasis and psoriatic arthritis. The review cites several clinical trials that have demonstrated the drug's efficacy in reducing symptoms and improving quality of life for patients.

In conclusion, while there may be some cases of resistance to Cosentyx, overall the drug remains an effective treatment for psoriasis and psoriatic arthritis. Its patent is set to expire in 2034, indicating that there have been no significant changes in its effectiveness that would warrant a new patent.

Sources:
[1] https://www.drugpatentwatch.com/p/biologics/tradename/COSENTYX
[2] https://www.medicalnewstoday.com/articles/326632
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6422944/