Yervoy is a brand name for the drug Ipilimumab, which is used to treat cancer. According to the sources provided, there are no specific restrictions on Yervoy discounts. However, the drug is still under patent protection until 2022 [1]. This means that there may be limited availability of generic versions of the drug, which could affect the availability of discounts. Additionally, the Health Resources and Services Administration (HRSA) manages the 340B Drug Pricing Program, which requires drug manufacturers to provide discounts to certain eligible healthcare organizations [2]. It is possible that Yervoy may be included in this program, but it is not specified in the sources provided.

Furthermore, the sources indicate that the manufacturer of Yervoy, Bristol-Myers Squibb, has faced challenges in maintaining revenue from the drug due to competition from other cancer treatments [3]. This could potentially affect the availability and size of discounts offered by the company.

In summary, while there are no specific restrictions on Yervoy discounts, the availability and size of discounts may be affected by factors such as patent protection, eligibility for discount programs, and competition from other cancer treatments.

Sources:
[1] https://www.drugpatentwatch.com/p/biologics/tradename/YERVOY
[2] https://www.hrsa.gov/opa
[3] https://www.reuters.com/article/us-gsk-cancer/glaxo-scientists-work-to-rebuild-cancer-line-up-funding-uncertain-idINKBN0IP2HH20141105