Patent landscape in hydroxamic acid-based HDAC inhibitors (2020–2024): structure–activity relationships and mechanistic insights

Introduction: The hydroxamic acid-based histone deacetylase (HDAC) inhibitors play a crucial role as anticancer chemotherapeutics. It controls cellular pathways and epigenetically modifies gene expression, making them important for tackling the complicated character of cancer etiology. Areas covered: The action of current HDAC inhibitors on different target proteins and multiple-cancer cell lines are studied. The study underlines a comprehensive summary of different compounds published as patents from 2020 to 2024 and retrieved from Google patents, paying special attention to their structural differences and possible applications in cancer treatment. It stands out in today’s scenario by providing structure–activity relationships (SAR) and mechanistic insights for heterocyclic scaffold-like pyrimidine, quinazoline, oxadiazole, thiadiazole, thiazole, piperazine, pyridine, indole and chromane rings used in the design of HDAC inhibitor. Expert opinion: Results reveal significant development in the synthesis of selective HDAC inhibitors with IC₅₀ values in the nano and micromolar range, exceeding conventional inhibitors as vorinostat. Dual-targeting approaches have also evolved as sensible substitutes using molecules that improve treatment efficacy while reducing side effects. Thorough investigation on SAR across various heterocyclic scaffolds benefits future drug development projects, aimed at improving selectivity and minimizing side effects in cancer treatment.