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MAJOR CONCERNS FOR MINOR SPECIES by Karen A. Kandra On September 12-13, 1996, FDA cosponsored the eighth NRSP-7/FDA workshop titled, "Drug Availability for Minor Species in the 21st Century." Animal producers, veterinarians, scientists, and regulators attended the workshop to exchange ideas on approaches to disease problems and drug priorities. The USDA/Cooperative State Research, Education, and Extension Service National Research Support Project No. 7 (NRSP-7) is designed to address the shortage of minor use animal drugs by funding and overseeing the efficacy, animal safety, human food safety research and the environmental assessment required for drug approval. Minor animal drug uses are analogous to human orphan drug uses, for which the market is insufficient to justify the costly research expenditures by a pharmaceutical firm necessary to obtain FDA approval. Minor species are defined by exclusion. That is, any that are not major species. Major species are horses, cattle, swine, turkeys, chickens, dogs, and cats. Minor species include sheep, goats, fish, gamebirds, rabbits, ratites, and deer among others. Minor uses also include certain diseases in major species that occur infrequently or in limited geographical locations. Projects are prioritized from Animal Drug Requests which originate from a variety of sources: producer groups, academicians, and pharmaceutical companies. The regional coordinators, principal investigators, and CVM collaborate to determine what data is required to support safety and efficacy claims for the product requested, and then to develop protocols for any necessary studies. Results of these studies are reviewed by CVM, and ultimately are placed in a Public Master File, which may be used by a pharmaceutical company to support an original or supplemental New Animal Drug Application (NADA). In the past 10 years, NRSP-7 has received over 280 requests. The majority of these requests are not feasible for one reason or another. However, the data necessary to support approvals for 24 of these requests have been published as Public Master Files. Of these, 19 have been used to support supplemental NADA's, and have been approved. Two complete files have not been acted upon by the company. Three requests have been recently completed and are waiting for filing of supplemental NADA's. These are formalin for fish, sulfadimethoxine/ormetoprim for chukar partridges, and ivermectin injection for bison. NRSP-7 has several additional public master files nearing completion. There are currently more than 30 other projects in development for more than 17 drugs and 10 species. At the September workshop, introductory comments were made by Dr. Alistair I. Webb, University of Florida, and Drs. Stephen Sundlof and Andrew Beaulieu of the Center for Veterinary Medicine (CVM). Dr. Andres de la Concha from the Texas Agriculture Experiment Station followed with a discussion of the lack of drugs to treat diseases of sheep and goats. Internal parasites and pneumonia are the most important diseases of sheep and dairy goats. Dr. de la Concha cited antibiotics and anthelmintics as the most needed drugs. Dr. Lowell Wilson, Pennsylvania State University, addressed the medical needs of veal calves. He stated that the average slaughter age is now 19-20 weeks, doubling in the last 10 years. He sees the following drug needs for veal calves: amoxicillin, ampicillin, penicillin, and decoquinate. Dr. Barry Marshall, New Zealand Embassy, spoke about farm raised deer. He said that about 1.5 million deer are farmed in the United States on 4,500 farms. The market for New Zealand venison exports is about $144 million, and live deer about $600,000. Mr. Bill MacFarlane of MacFarlane Pheasant Farm, Janesville, Wisconsin, addressed problems associated with the production of game birds. About 25 to 50 million birds are produced annually. These birds are raised outdoors, and stress is a concern. Gapeworm and blackhead are common diseases. Medications provided in drinking water are not practical since birds drink from puddles during rainy seasons. The need for approved medicated feeds is critical since extra-label use does not apply to medicated feeds. Dr. Thomas Nickerson, Weaverville, CA, discussed drug availability for ratites. Emus are popular for their meat and leather; ostriches for meat, feathers, and hide; and rheas for body fat on the tail used to make oil for moisturizing skin. Drugs are needed to treat diseases such as avian influenza, external parasites, flukes, and equine encephalitis in emus. Most diseases attack young birds under 3 months of age, and the birds are not slaughtered until approximately 10 months of age. The ratites have a renal-portal system which carries drugs directly to the kidney, causing more toxicity, which is a unique problem. Dr. William Lance, Wildlife Pharmaceuticals, Inc., discussed the needs of zoologic species. This is a focused market, since only about 10,000 animals are included. Major needs are reproductive modifiers, long-acting neuroleptics, sustained-release antibiotics, and anthelmintics. Dr. John Pitts, Quicene, WA, addressed the problems of aquaculture. The aquaculture industry has successfully cooperated with CVM and the pharmaceutical industry in prioritizing the drug needs of the industry and assisting with studies to support future approvals. The need for medicated feeds is also paramount in this industry. Dr. Ruth Francis-Floyd, University of Florida, discussed the problems of the ornamental fish industry. This is an industry worth over fifty million dollars per year where there are no approved drugs. Aquarium fish are growing in popularity and the biggest problems facing the species are external parasites, bacterial infections, and fungal infections. Dr. Chris Hayhow, Hoechst Roussel, addressed the drug availability issues for rabbits, a species which has a growing market in fur, exhibition, pets, and laboratory areas. He estimated that 2.3 million households have rabbits, with pet ownership increasing rapidly. Special challenges facing rabbit enthusiasts are disease, parasites, and production problems in their animals. There are currently only three approved products: sulfaquinoxaline, lasalocid, and tetracycline. Dr. Brad Smith, Oregon State University, reported on the growing popularity of llamas. With about 100,000 in North America, they are increasing at a rate of about 25 percent per year. Now used as companion animals, as well as for guarding sheep, they are prone to P. tenuis, a gastrointestinal nematode, liver flukes, and bacterial diseases like tuberculosis, Johne's disease, and brucellosis. The alpaca is a smaller animal, similar to llamas, very popular for its quality fur. Both llamas and alpacas are gaining in popularity and long-term growth of the industry is expected. On the second day of the workshop, speakers from the pharmaceutical industry presented their perspective on the problem. There was common agreement that firms adding minor species claims to their labels increase legal liability. This potentially places the company's assets and major species claims at risk. Despite these risks, several companies have gone through the process of supplementing their approved labels with minor species claims. In order to successfully expand the availability of minor use therapeutants, there is a need for NRSP-7, pharmaceutical companies, and CVM to collaborate early in the product development planning, including the design of study protocols. These cooperative efforts benefit all parties and expedite the process. The workshop concluded with a lively panel discussion chaired by Dr. Robert Ringer, the National Coordinator of the NRSP-7 program. Members of the panel included Dr. Joe Gloyd of AVMA, Dr. James Wilkerson, a lawyer and veterinarian, Dr. Harold Hafs of Rutgers University, Dr. Kurt Mann, a veterinary advisor to the House Committee on Agriculture, Dr. Michael Blackwell, Deputy Director of the FDA Center for Veterinary Medicine, and Dr. Richard Carnevale of the Animal Health Institute. The discussion touched on many issues introduced throughout the 2-day workshop. Most comments concentrated on how to improve the program so as to increase availability of therapeutic drugs labeled for minor species, and means to address the problems facing specific industries. NRSP-7 will publish the proceedings from this workshop by the summer of 1997. Anyone interested in receiving a copy can contact Dr. Alistair Webb at the College of Veterinary Medicine at the University of Florida. His telephone number is (352) 392-4700, extension 3828. CVM also has recently finalized a revision of the Minor Use Guidance Document: A Guide to the Approval of Animal Drugs for Minor Uses and for Minor Species. The availability of this publication will be announced in the Federal Register and the FDA Veterinarian in the near future.
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