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Conditional Approval Explained: A Resource for Veterinarians

 


What animal drugs are eligible for conditional approval under the MUMS Act?
What animal drugs are eligible for expanded conditional approval?
What's the difference between conditional approval and full approval?
What does FDA's conditional approval allow a drug company to do?
What happens if the drug company can't complete the effectiveness requirements before the conditional approval terminates?
What is the goal of conditional approval for MUMS drugs?
What is the goal of expanded conditional approval for non-MUMS drugs?
How does conditional approval benefit you and your patients?
Can you use conditionally approved animal drugs in ways that are not listed on the label (extra-label use)?
Which office in FDA's Center for Veterinary Medicine oversees conditional approval?
Should you report problems related to a conditionally approved animal drug?
What does the "CA1" mean after the name of a conditionally approved animal drug?
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In 2004, Congress passed the Minor Use and Minor Species Animal Health Act (commonly called the "MUMS Act") to help FDA ensure that innovative treatments are available for small populations of animals and species that have few drugs approved for them. This law added provisions to the Federal Food, Drug, and Cosmetic Act to increase the availability of drugs for minor species, such as ferrets and fish, and for minor uses in a major species, such as to treat certain types of cancer in dogs. One main provision created a new pathway called conditional approval to bring these "MUMS drugs" to the marketplace more quickly.

In 2018, Congress further expanded FDA’s authority to grant conditional approval to certain non-MUMS drugs that wouldn’t be eligible for conditional approval under the MUMS Act. 

Conditional approval differs from full approval in several ways, and these key differences have implications for veterinarians who prescribe conditionally approved animal drugs in their practices.

What animal drugs are eligible for conditional approval under the MUMS Act?

Under the MUMS Act, only animal drugs for minor species or minor uses in a major species are eligible for conditional approval. Minor species are all animals that are not one of the seven major species: horses, dogs, cats, cattle, pigs, turkeys, and chickens. A drug to treat a disease in sheep or goats, for example, is eligible for conditional approval because both are minor species. A minor use in a major species is the use of a drug in a major species for a condition that occurs:

  • Infrequently and in only a small number of animals each year; or
  • In a limited geographic area and in only a small number of animals each year.

FDA defines a “small number” as fewer than:

  • 50,000 horses;
  • 70,000 dogs;
  • 120,000 cats;
  • 310,000 cattle;
  • 1,450,000 pigs;
  • 14,000,000 turkeys; and
  • 72,000,000 chickens.

A drug to control pain in dogs with bone cancer is eligible for conditional approval because fewer than 70,000 dogs typically get bone cancer each year.

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What animal drugs are eligible for expanded conditional approval?

Animal drugs are eligible for expanded conditional approval if they’re for use in one of the seven major species (horses, dogs, cats, cattle, pigs, turkeys, and chickens) and they address:

  • a serious or life-threatening condition, but demonstrating effectiveness would require complex or particularly difficult studies; OR
  • an unmet animal or human health need, but demonstrating effectiveness would require complex or particularly difficult studies.

FDA has a guidance document that explains the eligibility criteria for expanded conditional approval.

What’s the difference between conditional approval and full approval?

For both conditional approval and full approval, the drug company must prove, among other things, that the animal drug is safe when used according to the label. The difference lies in the effectiveness requirement.

For full approval, the drug company must provide “substantial evidence" of the drug's effectiveness. For conditional approval, the drug company must show that the drug has a “reasonable expectation of effectiveness,” but has not yet proven that it meets the “substantial evidence” standard of effectiveness for full approval.

Conditionally approved animal drugs must state on the labeling: "Conditionally approved by FDA pending a full demonstration of effectiveness under application number XXX-XXX.”

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What does FDA’s conditional approval allow a drug company to do?

FDA’s conditional approval allows the drug company to legally sell the animal drug before proving it meets the “substantial evidence” standard of effectiveness for full approval. The company can also legally promote and advertise the conditionally approved drug for the labeled uses.

The conditional approval is valid for one year. The drug company can ask FDA to renew the conditional approval annually for up to four more years, for a total of five years of conditional approval. To receive a renewal from FDA, the company must show active progress toward proving “substantial evidence of effectiveness” for full approval.

During the conditional approval period, the company can legally market the animal drug for the labeled uses while collecting the remaining effectiveness data. After collecting the necessary data, the company then applies to FDA for full approval. FDA reviews the application and, if appropriate, fully approves the drug.

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What happens if the drug company can’t complete the effectiveness requirement before the conditional approval terminates?

If FDA grants all four annual renewals, the drug company has up to four-and-a-half years to develop and submit the necessary data to complete the effectiveness requirement. If the company does not submit all necessary information to support full approval by this four-and-a-half-year deadline, the conditional approval terminates immediately. The drug company must stop marketing the drug because it is now considered to be unapproved.

If the company submits the necessary information before the four-and-a-half-year deadline, the conditional approval period runs another six months, for a total of five years, while FDA reviews the application for full approval. The conditional approval automatically terminates five years after the date of the initial conditional approval. If FDA does not fully approve the drug before the five-year termination date, the drug company must stop marketing the drug because it is now considered to be unapproved.

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What is the goal of conditional approval for MUMS drugs?

Not many MUMS drugs are on the market. This can be explained by two main reasons. First, it’s very expensive for a drug company to develop a drug and get it approved by FDA. Second, the market for a MUMS drug is too small to generate an adequate financial return for the company. The combination of the expensive drug approval process and the small market often makes drug companies hesitant to spend a lot of resources to develop MUMS drugs when there is so little return on their investment.

By allowing a drug company to legally market a MUMS drug early (before it is fully approved), conditional approval makes the drug available sooner to be used in animals that may benefit from it. This early marketing also helps the company recoup some of the investment costs while completing the full approval.

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What is the goal of expanded conditional approval for non-MUMS drugs?

Similar to conditional approval for MUMS drugs, the goal of expanded conditional approval is to encourage drug companies to develop drugs for major species for serious or life-threatening conditions and to fill treatment gaps where no therapies currently exist or the available therapies are inadequate.

How does conditional approval benefit you and your patients?

Conditional approval—for both MUMS and non-MUMS drugs—benefits you and your patients by allowing a needed animal drug to be legally available in a faster timeframe than a full approval, while also guaranteeing that the drug is safe and has a reasonable expectation of effectiveness when used according to the label. This greater access to critical animal drugs gives you more options for treating your patients with uncommon conditions, serious or life-threatening diseases, or diseases without adequate therapies. 

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Can you use conditionally approved animal drugs in ways that are not listed on the label (extra-label use)?

No. The Federal Food, Drug, and Cosmetic Act doesn't allow extra-label (also called “off-label”) use of conditionally approved animal drugs. You can only prescribe these drugs for the labeled uses. To drive this point home, the labeling for every conditionally approved drug explicitly states, “It is a violation of Federal Law to use this product other than as directed in the labeling.” This is different for fully approved drugs which, under certain conditions, you can legally prescribe for extra-label uses in animals.

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Which office in FDA’s Center for Veterinary Medicine oversees conditional approval?

The Office of New Animal Drug Evaluation (ONADE) oversees the conditional approval of any animal drug. However, if the drug is for a minor use in a major species, ONADE asks the Office of Minor Use and Minor Species Animal Drug Development (OMUMS, for short) to determine if the drug is eligible for conditional approval under the MUMS Act—that is, if the drug’s intended use is indeed a minor use in a major species. For example, if the drug is to treat a specific cancer in cats, it’s eligible for conditional approval only if OMUMS determines that less than 120,000 cats develop that type of cancer each year. 

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Should you report problems related to a conditionally approved animal drug?

Yes. FDA encourages veterinarians to report all problems related to any drug—fully approved, conditionally approved, or unapproved. Problems with an animal drug are called adverse events and include:

  • Side effects in treated animals, such as vomiting, diarrhea, colic, and seizures;
  • Side effects in people who handle or are exposed to the drug, such as needle stick injuries, rashes, headaches, and nausea;
  • The drug has a lack of effectiveness, such as it’s not working, it stops working, or it isn’t working as well as it did previously;
  • Medication errors, such as giving the wrong drug or the wrong dose; and 
  • Product defects, such as defective packaging (a broken seal, for example), the drug is off-color, or a new bottle has several crushed or broken tablets.

A drug company that markets a conditionally approved animal drug is required to submit to FDA all reports of adverse events that the company receives. FDA reviews the reports to identify potential safety and effectiveness concerns that may not have been apparent at the time of conditional approval. FDA conducts this post-marketing monitoring to make sure the drug continues to meet the required standards of safety and “reasonable expectation of effectiveness” established during the conditional approval process.

Please see How to Report Animal Drug Side Effects and Product Problems.

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What does the “CA1” mean after the name of a conditionally approved animal drug?

The “CA1” indicates that FDA conditionally approved (CA) the animal drug and that it’s the first (1) conditionally approved application for that particular drug. If FDA were to conditionally approve a second application for the drug, the suffix would then be “CA2.” If FDA fully approves the drug, “CA1” is no longer included after the drug’s name.

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For More Information

If you have questions or want more information, please contact the Education & Outreach Staff at FDA's Center for Veterinary Medicine at 240-402-7002 or AskCVM@fda.hhs.gov.

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