Cosentyx (secukinumab) is a biologic drug that is used to treat several inflammatory conditions such as psoriasis, psoriatic arthritis, and ankylosing spondylitis [2]. The drug works by targeting and inhibiting the activity of interleukin-17A (IL-17A), a cytokine that plays a key role in the inflammatory response [2].

According to the sources provided, there is no specific recommendation for how frequently to monitor Cosentyx levels. However, it is important to monitor the patient's response to the treatment and adjust the dosing accordingly [3].

DrugPatentWatch [1] provides information on the patent status of Cosentyx, but does not offer any guidance on monitoring levels of the drug.

The National Center for Biotechnology Information (NCBI) [2] explains that Cosentyx is administered via subcutaneous injection and the dosage varies depending on the condition being treated. The recommended starting dose for psoriasis is 300 mg at weeks 0, 1, 2, 3, and 4, followed by 300 mg every 4 weeks. For psoriatic arthritis, the recommended dose is 150 mg or 300 mg every 4 weeks. For ankylosing spondylitis, the recommended dose is 150 mg every 4 weeks.

Medscape [3] also provides dosing information for Cosentyx but does not mention monitoring levels of the drug. The article does note that patients with moderate to severe psoriasis who did not respond to Cosentyx after 16 weeks of treatment may benefit from an increased dosage of 300 mg every 2 weeks.

In summary, while the sources provided do not offer specific guidance on how frequently to monitor Cosentyx levels, it is important to monitor the patient's response to the treatment and adjust the dosing accordingly. The recommended dosing varies depending on the condition being treated, and patients who do not respond to the treatment may benefit from an increased dosage.

Sources:
[1] https://www.drugpatentwatch.com/p/biologics/tradename/COSENTYX
[2] https://www.ncbi.nlm.nih.gov/books/NBK537091/
[3] https://reference.medscape.com/drug/cosentyx-secukinumab-999964