The Safety of Zidovudine Plus Interferon-Alpha in HIV-Infected Children

AZT is effective in suppressing the progression of HIV infection in patients without symptoms or with AIDS or AIDS-related complex (ARC). However, use of AZT is limited by its frequent toxicity, which sometimes relates to the amount of drug given. Thus, a combination treatment of two drugs that work together may provide more effective and safer treatment. IFN-A is a drug that has antiviral effects and may work well with AZT.

The study is being conducted in three stages. In Cohort A (IFN-A alone), four patients receive IFN-A; subsequent four-patient cohorts receive doses escalated in increments. If 50 percent or more of patients at any dose level experience grade 2 or better toxicity, doses in subsequent cohorts are escalated. If grade 3 or 4 toxicity is seen in one patient at a given dose level, two additional patients are enrolled at that level. Treatment is given subcutaneously (under the skin, with a needle), 3 times per week for 12 weeks. The MTD is defined as the dose level immediately below that at which 50 percent or more of patients experience grade 3 or 4 toxicity. In Cohort B (combination IFN-A plus AZT), patients who complete treatment in Cohort A continue on the same dose of IFN-A, and a low, middle, or high dose of AZT is added. In Cohort C, four newly assigned patients who have been on a stable prescribed dose of AZT of at least 90 mg/m2 for 6 weeks are treated at each of the same dose combinations as those in Cohort B. Treatment is given for 12 weeks. IFN-A is given subcutaneously 3 times a week and AZT is given orally every 6 hours. Dose levels of both drugs are increased until 50 percent or more of patients experience grade 3 or 4 toxicity in any dose level.

Inclusion criteria

Concurrent Medication:

Recommended:

• Prophylaxis for Pneumocystis carinii pneumonia.

Allowed:

• Aerosol ribavirin for short-term treatment of acute respiratory syncytial virus (RSV).
• Immunization according to the current recommendations of the Advisory Committee for Immunization Practice.
• IVIG. Systemic ketoconazole, acyclovir, or oral nystatin for acute therapy.

Patients must have the following:

• HIV infection. Patients with proven resistance to AZT are also eligible.

Prior Medication:

Allowed:

• Aerosol ribavirin.

Required:

Cohort C treatment:

• Stable prescribed dose of zidovudine (AZT) >= 90 mg/m2 for at least 6 weeks prior to study entry.

Exclusion criteria

Co-existing Condition:

Patients with the following conditions or symptoms are excluded: AIDS or class P-2B, D, or E symptomatic infection.

Concurrent Medication:

Excluded:

• Hepatotoxic or neurotoxic drugs, immunosuppressants, or antiseizure medication. Ketoconazole, fluconazole, and acyclovir for prophylaxis. Immunomodulators (other than IVIG). Experimental drugs.

Cohort A patients:

• AZT for clinical indications.

Prior Medication:

Excluded:

• Other antiretroviral agents (including didanosine (ddI), dideoxycytidine (ddC), or soluble CD4) within 1 month of study entry. Systemic ribavirin administered for retroviral therapy within 2 months of study entry.
• Immunomodulating agents including interferon, isoprinosine, interleukin-2, or lymphocyte transfusions within 4 weeks of study entry.
• RBC transfusion within 4 weeks prior to study entry.

Alcohol or drug abuse.