Yes, Cosentyx has been tested in pediatric populations. According to the sources provided, the U.S. Food and Drug Administration (FDA) has approved Cosentyx for the treatment of children and adolescents with enthesitis-related arthritis and psoriatic arthritis [3]. This indicates that the drug has undergone clinical trials and demonstrated efficacy and safety in pediatric patients.

The website for Cosentyx also provides information on the use of the drug in pediatric populations, specifically for pediatric psoriasis [2]. The website states that Cosentyx is approved for children and adolescents aged 6 years and older with moderate to severe plaque psoriasis. It also mentions that the safety and effectiveness of Cosentyx in pediatric patients with psoriatic arthritis or ankylosing spondylitis have not been established.

Furthermore, the Drug Patent Watch website confirms that Cosentyx is indeed a biologic drug that has been tested and approved for pediatric use [1]. This supports the information provided by the other sources.

In conclusion, Cosentyx has undergone clinical trials and received FDA approval for the treatment of pediatric patients with enthesitis-related arthritis and psoriatic arthritis. It is also approved for pediatric psoriasis. However, its use in other pediatric conditions such as psoriatic arthritis or ankylosing spondylitis has not been established.

Sources:
[1] Drug Patent Watch. Cosentyx - Trademark, Owner Novartis. Retrieved from https://www.drugpatentwatch.com/p/biologics/tradename/COSENTYX
[2] Cosentyx. Kids and Teens - Pediatric Psoriasis. Retrieved from https://www.cosentyx.com/kids-and-teens/pediatric-psoriasis
[3] Novartis. Novartis' Cosentyx receives FDA approval for treatment of children and adolescents with enthesitis-related arthritis and psoriatic arthritis. Retrieved from https://www.novartis.com/news/media-releases/novartis-cosentyx-receives-fda-approval-treatment-children-and-adolescents-enthesitis-related-arthritis-and-psoriatic-arthritis