# FDA WARNING_LETTER - Elanco US Inc. dba Elanco Animal Health - March 11, 2025

Source: https://www.globalkeysolutions.net/records/warning_letter/elanco-us-inc-dba-elanco-animal-health/3ac6d58e-c232-44de-b132-6d33f83160d6

> FDA WARNING_LETTER for Elanco US Inc. dba Elanco Animal Health on March 11, 2025. Product: Veterinary. Access full analysis and detailed observations.

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## Details

- Record Type: WARNING_LETTER
- Company Name: Elanco US Inc. dba Elanco Animal Health
- Inspection Date: 2025-03-11
- Product Type: Veterinary
- Office Name: Center for Veterinary Medicine
- Summary: On January 28, 2025, the FDA issued a Warning Letter to Mr. Simmons regarding promotional communications for Zenrelia (ilunocitinib tablets), citing false or misleading claims about its safety and effectiveness. The FDA reviewed the veterinarian product website, consumer-directed website, Product Brochure and Itch Tracker, and a slide deck titled “Reach for Zen: New Relief for Dogs with Atopic Dermatitis.”

Zenrelia, a recently approved JAK inhibitor, is indicated for pruritus and atopic dermatitis in dogs. Its FDA-approved Prescribing Information (PI) includes a boxed warning about the risk of "fatal vaccine-induced disease from modified live virus vaccines and inadequate immune response to any vaccine," requiring discontinuation of Zenrelia for 28 days to 3 months prior to vaccination and 28 days after. The PI also warns of increased susceptibility to opportunistic infections, decreased hematocrit/hemoglobin, and new neoplastic conditions.

The promotional materials misbrand Zenrelia under FD&C Act sections 502(a) and 502(n) by omitting crucial safety information. Specifically, they omit "from modified live virus vaccines" from the boxed warning and replace specific withholding periods (28 days to 3 months prior, 28 days after) with "for a time period before and after vaccination." The veterinarian website's Safety section also lacks mention of fatal vaccine-induced disease, inadequate immune response,

## Related Officers

- [Linda Walter-grimm](https://www.globalkeysolutions.net/people/linda-walter-grimm/f8aa1ecc-0dd5-493b-ad07-2bdb1cf71bbe)

Company: https://www.globalkeysolutions.net/companies/elanco-us-inc-dba-elanco-animal-health/d7b106fc-443b-4097-a57a-3563deebb0ad

Office: https://www.globalkeysolutions.net/offices/center-for-veterinary-medicine/7e30a309-56e4-4e7a-8b8b-e07674bb07b4