Fozivudine [BM 211290, fozivudine tidoxil, FZT, HDP 990002, W 09726867] is a thioether lipid conjugate of zidovudine (AZT) in clinical development with Heidelberg Pharma Holdings for the potential treatment of HIV infection. Heidelberg Pharma's proprietary Linker-Cleavag-Enzyme Technology (LCE_Technology) is used to conjugate specific carriers to parent compounds, significantly improving their pharmacological, toxicological and/or clinical profile.LCE_Technology was originated at Boehringer Mannheim, which was acquired by, and integrated into, Roche. In 1999, when Heidelberg Pharma was founded, following a management buy-out from Roche Diagnostics GmbH, the new company acquired full ownership of the intellectual property and documentation related to various proprietary compounds, the LCE_Technology and its applications.According to Heidelberg Pharma's pipeline, published in August 2003, the product candidate, HDP 99.0002 (the company-specific code for fozivudine) will be in phase III development until early 2006, at which time the company hopes to file an NDA.A phase II study of fozivudine in 72 antiretroviral-naive patients with HIV infection was completed in the US and France by Roche.