GLAXO OF CANADA, ICN CANADA WILL SUPPLY STREPTOMYCIN AND PAS TO U.S. TB PATIENTS

GLAXO OF CANADA, ICN CANADA WILL SUPPLY STREPTOMYCIN AND PAS TO U.S. TB PATIENTS until Pfizer resumes the manufacture of streptomycin and Jacabus Pharmaceuticals starts up production of PAS (para-amino salicylate sodium). The two drugs should be available from Glaxo Canada and ICN Canada by mid-April, FDA staffer Mary Pendergast reported at an April 2 House Government Operations/Human Resources subcommittee hearing on tuberculosis called by Chairman Ted Weiss (N.Y.). The Centers for Disease Control has agreed to sponsor an IND exemption allowing the two foreign manufacturers to supply the U.S. market. The companies plan to supply the drugs free of charge until Pfizer and Jacobus begin production. Pendergast also noted that another, as-yet unnamed company plans to produce streptomycin. The firms should be ready for full-scale marketing of the drugs in the fall, she said. Pfizer and Lilly manufactured second-line TB therapy streptomycin in the U.S. until last May. Lilly said that bulk supplier Rhone-Poulenc Rorer stopped supplying the product. PAS was previously made by the Lannett Company, which halted manufacturing last year after a management change. FDA has been concerned about TB drug shortages for several months ("The Pink Sheet" Jan. 27, T&G-10). To avoid further TB drug shortages, Pendergast said that FDA is planning to establish an "early alert system." The agency, in collaboration with the Pharmaceutical Manufacturers Association, will request manufacturers of TB therapies to contact the agency if they plan to scale back or cease production of the drugs. If manufacturers plan such production changes, Pendergast noted, FDA will notify physicians. Rep. Weiss also asked Pendergast if there are any shortages of first-line agent isoniazid (INH). She responded that the agency is aware of three generic manufacturers that produce the drug. On March 31, generic manufacturer Duramed announced that it will begin shipping INH to pharmacies after a two-year hiatus. The company renewed distribution of the drug after receiving validation of its manufacturing process from FDA March 26. Duramed had an approved ANDA for the product but ceased production in 1990 while it conducted internal audits of all its ANDAs. The firm's decision to resume manufacturing and marketing of INH is in "direct response" to the "recent resurgence" of TB, Duramed Chairman and President Thomas Arington stated. At a January meeting sponsored by CDC, FDA Division of Antiviral Drug Products medical officer Mark Goldberger commented that there could be temporary disruptions in the supply of Barr Labs' 300 mg strength INH and that the agency planned to expedite inspections of other interested companies in the event alternative U.S. suppliers were needed. Glaxo's BCG (bacillus Calmette-Guerin) TB vaccine was also discussed at the April 2 hearing. According to Jeffrey Starke, MD, Texas Children's Hospital, while the efficacy of the BCG vaccine has been found to be variable in some studies with adult subjects, it has shown some efficacy in children. He suggested that the vaccine could be considered for use in children, especially those at high-risk of exposure to cases of multi-drug resistant TB. In a recent study cited in the March 14 Lancet, the BCG vaccine was found to provide 50% or greater protection against leprosy, but no evidence was found for protection against TB. The study, conducted in northern Malawi, Africa by J. M. Ponninghaus, LEPRA Evaluation Project, Malawi, et al., analyzed the efficacy of the vaccine against leprosy and TB. In the 83,455 individuals followed up after vaccination between 1979 and 1989, 414 new cases of leprosy and 180 new cases of TB were found. In all analyses, the authors "found greater protection by the BCG vaccine against leprosy than against tuberculosis."