THE MANIFESTATION OF SCIENTIFIC ASPECTS OF CLASSIFICATION, CLINICAL USE, FEATURES, MECHANISM OF ACTION, PHARMACOLOGY, EFFECTS AND TOXICITIES OF NEW ANTICANCER DRUGS IN GENERAL

The landscape of anticancer drug development has transformed with the advent of targeted therapies, immunotherapies, and novel delivery systems, addressing the global burden of cancer, projected to reach 28.4 million cases by 2040. This article comprehensively reviews the classification, clinical use, features, mechanisms of action, pharmacology, therapeutic effects, and toxicities of new anticancer drugs, focusing on agents approved by the FDA and EMA as of March 2024. Drugs are classified by their site of action (e.g., tumor cell nucleus, cytoplasm, vasculature, immune, and endocrine systems) and mechanism (e.g., DNA damage, kinase inhibition, immune modulation). Key classes include antibody-drug conjugates (ADCs) like trastuzumab deruxtecan, tyrosine kinase inhibitors (e.g., osimertinib), immune checkpoint inhibitors (e.g., pembrolizumab), and natural or repurposed agents (e.g., paclitaxel, metformin). Mechanisms range from DNA cross-linking and microtubule disruption to immune activation and angiogenesis inhibition. Pharmacologically, small molecules offer oral bioavailability but face metabolism challenges, while biologics require parenteral administration. Advanced delivery systems, such as nanoparticles and ADCs, enhance specificity. Therapeutic effects include improved overall survival and response rates, though toxicities like myelosuppression, cardiotoxicity, and immune-related adverse events persist. Emerging approaches, including nanotechnology, natural products, and drug repurposing, alongside AI-driven design, promise to overcome resistance and optimize outcomes. This review underscores the scientific advancements driving precision oncology while highlighting challenges in toxicity management and global accessibility. The landscape of oncology therapeutics has been radically transformed by the development of new anticancer drugs that move beyond traditional cytotoxic agents. This review comprehensively examines the scientific aspects of these novel compounds, focusing on their modern classification, intricate mechanisms of action, and clinical applications. We categorize these agents into targeted therapies, including small molecule inhibitors and monoclonal antibodies designed against specific molecular aberrations (e.g., kinase activity, signaling pathways), and immunotherapeutic agents, such as immune checkpoint inhibitors (e.g., PD-1/PD-L1, CTLA-4 inhibitors), CAR-T cells, and cancer vaccines, which harness the host's immune system to combat malignancy. The discussion delves into the unique pharmacologic features of these drugs, including their design principles, structure-activity relationships, and pharmacokinetic profiles, which often differ significantly from conventional chemotherapy. A detailed analysis of their precise mechanisms of action elucidates how they induce cell cycle arrest, promote apoptosis, inhibit angiogenesis, and modulate the tumor microenvironment. While these therapies offer superior efficacy and reduced off-target effects in specific patient populations, they are associated with a distinct spectrum of adverse effects and toxicities, such as immune-related adverse events (irAEs), dermatologic reactions, and unique organ-specific inflammatory syndromes, which necessitate specialized management protocols. This synthesis underscores the paradigm shift towards personalized medicine in oncology, driven by biomarker-driven drug selection. It highlights the critical interplay between molecular pathology, drug design, clinical efficacy, and toxicity management, while also acknowledging ongoing challenges like drug resistance and the imperative for continued research into novel targets and combination strategies to improve patient outcomes.