Differential toxicity of carbovir and AZT to human bone marrow hematopoietic progenitor cells in vitro.

We have studied the in vitro effects of carbovir as compared to 3'-azido-3'-deoxythymidine (AZT) on the growth of clonal bone marrow-derived hematopoietic progenitor cells. (-)Carbovir, the enantiomer with anti-human immunodeficiency virus (HIV) activity, exhibited significantly less toxicity to hematopoietic cells than AZT. These in vitro studies suggest that (-)carbovir will exhibit less hematologic toxicity in the therapy of patients infected with HIV either as a single agent or in combination with other agents that inhibit HIV proliferation.