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  1. Development & Approval Process

MUMS Definitions
The Minor Use and Minor Species Animal Health Act of 2004
Conditional Approval
Other Provisions for Minor Use and Minor Species Products 
Consumer Information about MUMS
Additional Information

MUMS Definitions

“Minor use” drugs are for intended uses in major species (horses, dogs, cats, cattle, pigs, turkeys, and chickens) for diseases that occur infrequently or in limited geographic areas and in only a small number of animals annually.

“Minor species” are all animals other than humans that are not one of the major species. They include animals such as zoo animals, ornamental fish, parrots, ferrets, and guinea pigs. Some animals of agricultural importance are also minor species. These include sheep, goats, catfish, game birds, and honey bees among others.


OMUMS Actions

The National Turkey Federation (NTF) requested a determination of whether “treatment of Blackhead in turkeys” would constitute a minor use in a major species. OMUMS was able to determine that this intended use would be a minor use and NTF granted permission to post the letter so that potential sponsors can refer to it.

Usually such a request comes from a pharmaceutical sponsor seeking approval for a specific new animal drug.  In this case, NTF wished to establish minor use status for this indication in order to facilitate sponsorship to pursue approval of a product to treat Blackhead in turkeys, for which there currently is no treatment. Having the option to take advantage of the incentives associated with “minor use” status (user fee waivers, designation, conditional approval) may encourage a company to seek approval of a candidate drug for this urgent need.  

OMUMS Members Education and Outreach

Members of the Office of Minor Use and Minor Species Animal Drug Development (OMUMS) have taken advantage of several learning opportunities.  These include:

  • A member of OMUMS presented on a panel at the 2023 American Association for Laboratory Animal Science (AALAS) National Meeting.  The presentation provided updates on the indexing program and information on the different legal marketing statuses for new animal drugs.
  • Members of OMUMS continue to meet with various animal stakeholder groups to discuss their needs, and to provide education about and receive feedback on our incentive programs.  These meetings are an important part of OMUMS’ work to increase the availability of safe and effective drugs for minor uses and minor species.
  • OMUMS representatives also continue to meet with Australian regulatory counterparts with the goal of increasing interaction to better align efforts to get more products legally available to minor use and minor species populations.

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The Minor Use and Minor Species Animal Health Act of 2004

“The Minor Use and Minor Species Animal Health Act of 2004,” commonly referred to as the “MUMS act”, was signed into law on August 2, 2004. The law is intended to make more medications legally available to veterinarians and animal owners for the treatment of minor animal species and uncommon diseases in the major animal species.

This law provides innovative ways to bring products to market for these small populations and is designed to help pharmaceutical companies overcome the financial roadblocks they face in providing limited-demand animal drugs. Before this legislation, pharmaceutical companies would rarely attempt to bring such drugs to market, because the markets were too small to generate an adequate financial return.

The law modifies the Federal Food, Drug and Cosmetic Act in three key ways to provide for:

CONDITIONAL APPROVAL:  Within very specific criteria, a sponsor of an animal drug can apply for “conditional approval,” which allows the sponsor to make the drug available before collecting all necessary effectiveness data, but after proving the drug is safe in accordance with the full FDA approval standard and showing that there is a reasonable expectation of effectiveness. The drug sponsor can keep the product on the market for up to five years, through annual renewals, while collecting the remaining required effectiveness data.

While originally intended only for applications for products for minor uses and minor species, this option was expanded in 2018 to also include certain major uses in major species in order to incentivize development of new animal drugs for serious or life-threatening conditions or unmet animal or human health needs where demonstration of effectiveness would require a complex or particularly difficult study or studies.  FDA drafted a new guidance document (Guidance for Industry #261 - Eligibility Criteria for Expanded Conditional Approval of New Animal Drugs) to explain the eligibility criteria.

In all cases, this provision is managed by the Office of New Animal Drug Evaluation (ONADE), not by the Office of Minor Use & Minor Species Animal Drug Development (OMUMS).

DESIGNATION: This provision was modeled on the “Orphan Drug Act” for humans, which encourages pharmaceutical sponsors to develop drugs for rare diseases in people, by providing incentives for approval. Sponsors of “designated” new animal drugs are eligible to apply for grants to support safety and effectiveness testing. A sponsor that gains approval or conditional approval for a designated new animal drug receives seven years of exclusive marketing rights, which means the sponsor will face no competition from another sponsor marketing the same drug in the same dosage form for the same intended use for that time. More information on Drug Designation.

INDEXING:  In some cases, a minor species drug is intended for use in species that are too rare or too varied to be the subject of adequate and well-controlled studies in support of a drug approval. In such cases, FDA may add the intended use to the Index of Legally Marketed Unapproved New Animal Drugs for Minor Species (the Index). This provision is especially helpful to veterinarians treating zoo or endangered animals or classes of animals that include numerous different species, such as ornamental fish. This provision is limited to minor species that are not used as food for humans or other animals. More information on Drug Indexing.

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Other Provisions for Minor Use and Minor Species Products

WAIVERS FROM USER FEES:  Sponsors of minor use and minor species drug development projects are eligible to apply for waivers from user fees.  Although OMUMS determines whether a particular intended use in a major species constitutes a minor use, the waiver request itself is handled by ONADE, not OMUMS.

COMPLIANCE POLICY GUIDE (CPG) FOR EXTRA-LABEL USE OF MEDICATED FEEDS FOR MINOR SPECIES:  This guide (CPG 615.115) directs FDA field personnel to make the use of medicated feeds for minor species a low enforcement priority under the stated conditions. Extra-label use of medicated feeds is illegal. This guide does not make extra-label use legal or allow unapproved medicated feeds to be promoted or marketed for these uses. It simply makes it less likely that action will be taken against veterinarians and producers who use medicated feeds approved for use in other species for therapeutic purposes in minor species under the conditions stated in the CPG.

OUTSIDE PROGRAMS:  There are other government programs that support research directed toward drug approval for minor species. OMUMS works closely with these groups. Links to the websites for some of these are provided on this page under “Additional Resources.” You may also find useful links on CVM’s Aquaculture page.

Questions concerning MUMS should be addressed to the Office of Minor Use and Minor Species.

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Laws and Regulations


Compliance Policy Guides

Public Master File (PMF) Availability

Public Master Files contain information that sponsors can use to support new animal drug approvals. The studies in these files were conducted by public entities, so the information is available for anyone to use. Many MUMS new animal drug applications have used PMFs to support drug approvals.

Additional Resources

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