Study data presented Monday at the 43rd Interscience Conference on Antimicrobial Agents and Chemotherapy show that Roche and Trimeris's second-generation experimental fusion inhibitor, T-1249, can reduce the HIV viral loads of patients who have developed resistance to the companies' first fusion inhibitor, Fuzeon. Data from a Phase I/II study of the experimental drug showed that it was effective in significantly reducing the viral loads of 73% of patients who developed resistance to Fuzeon. No serious drug-related side effects were reported by the study volunteers. "The results from this study of T-1249 demonstrate that fusion inhibitors constitute an expanding class of anti-HIV drugs with the potential to be used sequentially," said Dani Bolognesi, CEO at Trimeris. Next up are Phase II clinical trials, which will begin in 2004.