Recent Advancement in Drug Designing as Small Molecules in Targeted Cancer Therapy: Challenges and Future Directions

The adverse outcome that patients experience as a result of anti-cancer therapy failure is primarily caused by metastasis. Making cancer a chronic disease with regular but controlled relapses is the real issue in increasing cancer patient lifespans. This can only be achieved by developing efficient therapeutic techniques that target critical targets in the metastatic process. New targeted therapy medications continue to emerge, and research into the molecular targeted therapy of tumors is flourishing. The ineffectiveness of conventional chemotherapy in targeting metastatic cells is primarily due to its ability to promote the selection of chemo-resistant cell populations that engage in epithelial-to-mesenchymal transition (EMT), which in turn encourages the colonization of distant sites and maintains the initial metastatic process. In considering this circumstance, research into a broad range of small molecules and biologics has been initiated to develop anti-metastatic medications that target particular targets implicated in the different stages of metastasis. With their ability to concentrate on cancer cells while avoiding normal cells, targeted medications offer a promising alternative to conventional chemotherapy that is both highly effective and relatively safe. Many obstacles, including an inadequate response rate and drug resistance, persist for small-molecule targeted anti-cancer medications, despite significant advancements in this area. We encouraged small-molecule-focused anti-cancer therapy development by extensively assessing them by target classification. We reviewed current challenges, listed licenced drugs and key drug candidates in clinical trials for each target, and made suggestions for improving anti-cancer drug research and development. This review aims to discuss present and future small molecule inhibitor research and development for cancer treatment.