Obstacles to Drug Development for HIV-Related Opportunistic Infections

have grown into an epidemic that threatens every group of people
in the United States and every country in the world. According to
the U.S. Centers for Disease Control (CDC), one million Americans
are currently infected with HIV. Each year, an additional 40,000
adults and adolescents become infected and from 1,500 to 2,000
children are infected perinatally.1 In June 1991, 176,047 cases and
111,815 deaths from AIDS had been reported to CDC.2 The projected cumulative number of AIDS cases through 1993 is from 390,000
to 480,000. Deaths are projected at 285,000 to 340,000 through
1993.3
Opportunistic infections occur in virtually all persons infected
with HIV and are responsible for 90 percent of all HIV-related
deaths.4 Opportunistic infections are by definition those which
occur when an immune system is compromised, and they are often
severe. Organisms involved may be those commonly present in the
human body, or others that invade the body and, in either case,
proliferate wildly when the immune system is weakened. HIV produces progressive damage to the host's immune system, especially
targeting a type of white cell known as the CD4+ cell. The only
approved therapies against HIV are AZT and ddl, which do not rid
the body of the virus; they can only hold the virus in check. At best
they merely slow the rate of decline of the immune system.5 There
is currently no cure for HIV infection. But it is the opportunistic
infections which actually cause illness and death in HIV-infected
persons. Therefore, the development of methods to diagnose, treat
and prevent opportunistic infections associated with HIV is of fundamental importance. It is for these reasons that the subcommittee
initiated its inquiry into the development of treatments for opportunistic infections.
On August 1, 1990, the subcommittee held an oversight hearing 6
and heard testimony from witnesses including physicians, community activists, representatives of the Federal Government and a
person with AIDS. They were Louis Grant, Associate Director,
Center for Constitutional Rights, New York, NY; Jean Flatley
McGuire, Executive Director, AIDS Action Council, Washington,
DC; Gabriel Ramon Torres, M.D., Attending Physician, St. Vincent's Infectious Disease Clinic, New York, NY; Gloria Goodwin,
R.N., Clinic Manager, Nelson-Tebedo Community Clinic for AIDS
Research, Dallas TX; Renslow Sherer, M.D., Director, AIDS Prevention Service, Cook County Hospital, Chicago, IL; Fred R.
Sattler, M.D., Associate Professor of Medicine, Department of Medicine, University of Southern California's School of Medicine, Los
Angeles, CA; and from the National Institutes of Health, Philip A.
Pizzo, M.D., Chief of Pediatrics, Head, Infectious Disease Section,
1 "HIV Prevalence Estimates and AIDS Case Projections for the United States: Report Based
upon a Workshop," Morbidity and Mortality Weekly Report, CDC, November 30, 1990.
2 "HIV/AIDS Surveillance," CDC, June, 1991.
O30p. cit., footnote 1.
4 Henry Masur, "Problems in the Management of Opportunistic Infections in Patients Infected with Human Immunodeficiency Virus," The Journal of Infectious Diseases, May, 1990, vol.
161, p. 858.
5 Michael Youle, "The Opportunistic Infections of HIV Disease," AIDS/HIV Treatment Directory, American Foundation for AIDS Research, September 1990, p. 2.
6 Hearing before a subcommittee of the Committee on Government Operations, U.S. House of
Representatives, "Treatments for Opportunistic Infections in Persons with HIV Disease,"
August 1, 1990, hereafter referred to as "Hearing."