Didanosine: long-term follow-up of patients in a phase 1 study.

Long-term follow-up of 44 patients with AIDS or AIDS-related complex (ARC) in a phase 1 trial of didanosine is reported. These patients were monitored for as long as 72 weeks (mean, 34 weeks) for toxicity and activity of didanosine. Pancreatitis and neuropathy, the major clinical toxicities, developed infrequently at the doses of didanosine (250-750 mg/d) employed during the latter part of the study. Consistent hematologic toxicity was not encountered; moreover, mean values for hematologic parameters such as hemoglobin concentration, white blood cell count, neutrophil count, lymphocyte count, and platelet count improved for up to 20-60 weeks. CD4 counts increased significantly through 10 weeks of therapy and in some patients remained at or above counts at enrollment for as long as 60 weeks. Serum concentrations of p24 antigen decreased significantly and remained at the decreased level for up to 48 weeks. An initial diagnosis of ARC (as opposed to AIDS), an initial CD4 count of > 100/mm3, and an increase in CD4 counts during the first 10 weeks of therapy were associated with a higher rate of survival and with lower rates of development of opportunistic infections and of other clinical manifestations of disease progression.