Nucleoside reverse transcriptase translocation inhibitors (NRTTIs) are a novel class of antiretroviral agents that inhibit HIV replication by targeting the viral reverse transcriptase enzyme and specifically blocking its translocation step during DNA synthesis, a critical process in the viral replication cycle.

When it won U.S. FDA accelerated approval more than eight years ago, Intercept Pharmaceuticals Inc.’s Ocaliva (obeticholic acid) was viewed as a breakthrough, becoming the first new treatment in 20 years for rare, progressive liver disease primary biliary cholangitis (PBC) and, for several years, the only second-line treatment for PBC patients failing to respond to ursodeoxycholic acid. More recently, however, Ocaliva has faced regulatory and safety stumbles, with Intercept now voluntarily pulling the farnesoid X receptor activator from the U.S. market.

Positive results for Revolution Medicines Inc.’s phase I studies of its lead candidate, the RAS-blocker daraxonrasib for treating pancreatic ductal adenocarcinoma, prompted the company to say it’s time for a phase III study in the aggressive cancer. Revolution said it plans to begin a global, randomized and registrational trial in first-line metastatic disease sometime in the fourth quarter of 2025.