Is Varenzin-CA1 Approved for Dogs? The Cats-Only Conditional Label Explained
No. Varenzin-CA1 (molidustat oral suspension) is conditionally approved by FDA for the control of nonregenerative anemia associated with chronic kidney disease (CKD) in cats, and its label says "For oral use in cats only." FDA states that conditionally approved drugs may only be used as the label directs, and the labeling says that using one in any other way is a violation of federal law. Nothing in the US label creates a dog indication.
What the US label says
The current DailyMed label for Varenzin-CA1 contains four statements that settle the species question:
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Species: "For oral use in cats only."
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Indication: "Varenzin-CA1 is indicated for the control of nonregenerative anemia associated with chronic kidney disease (CKD) in cats."
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Regulatory status: "Conditionally approved by FDA pending a full demonstration of effectiveness under application number 141-571."
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Legal warning: "It is a violation of Federal law to use this product other than as directed in the labeling."
The label also states that the drug is a prescription drug, restricted to use by or on the order of a licensed veterinarian. The indication names both a condition (nonregenerative anemia associated with CKD) and a species (cats). A different anemia in a cat, or the same anemia in a dog, is outside the label.
Why the active ingredient does not change the answer
An approval attaches to a specific product, formulation, species and indication. Molidustat is the active ingredient, but FDA conditionally approved one product, Varenzin-CA1, for one use in one species. Research on an ingredient in another species, in people, or in another country cannot extend that approval to dogs.
Conditional approval is also different from full approval. For both, the company must show that the drug is safe when used according to the label. For conditional approval, the company needs to show only a reasonable expectation of effectiveness, not yet "substantial evidence." FDA conditionally approved Varenzin-CA1 on May 1, 2023, as the first drug for this condition in cats. The "CA1" suffix means FDA conditionally approved the drug and this is its first conditionally approved application.
The label's evidence for a reasonable expectation of effectiveness comes from a 28-day, masked, randomized, controlled field study of 21 client-owned cats (15 treated, 6 vehicle control). Treatment success was 50% (7 of 14 evaluable cats) with the molidustat formulation versus 16.7% (1 of 6) with vehicle control, which the label calls numerically superior. FDA's approval announcement also tells veterinarians to advise owners of possible side effects, including vomiting, increases in systolic blood pressure and thromboembolism.
Conditional approval lasts one year and can be renewed annually for up to four more years, for a total of five. If the company does not complete the effectiveness requirement, it must stop marketing the drug, which then becomes unapproved. FDA says the expanded conditional approval program under which the drug was approved will sunset in 2028.
The main practical difference concerns extra-label use. FDA states that the Federal Food, Drug, and Cosmetic Act does not allow extra-label use of conditionally approved animal drugs. A veterinarian can only prescribe them for the labeled uses, which is different from fully approved drugs, which under certain conditions can be prescribed for extra-label uses.
Match the bottle and carton to the label
Compare each field on the package in front of you with what the US label describes.
The label revision date on the record is 05/2025, and the DailyMed record was last revised in 07/2025. If the package differs from the label, such as a different strength, a different species statement, no application number or a non-US labeler, note exactly which field differs. A seller page, retailer listing or online description does not replace the label and its application number.
Claims the label does and does not support
If something does not match
Photograph the carton, bottle label and syringe, and keep the receipt or pharmacy label. Write down the name, strength, species statement, regulatory statement, labeler and lot number as printed. Do not give the product to a dog, and do not give a mismatched product to a cat while the question is open.
Take the record to the prescribing veterinarian or the dispensing pharmacy and ask them to confirm that the product is the US-labeled Varenzin-CA1. If a pet or person may have swallowed the product, the label tells people to seek medical advice immediately and to keep the product out of reach of dogs, cats and other animals. For a pet, contact a veterinarian or an animal poison control service.
To report a suspected adverse reaction, the label lists Elanco US Inc. at 1-888-545-5973 and FDA at 1-888-FDA-VETS. FDA also encourages reports of product defects, medication errors and lack of effectiveness, whether or not a drug is fully approved. A mismatch is something to bring to a professional or regulator to resolve, not to resolve by administering the product.