Dual-Warhead Conjugate Based on Fibroblast Growth Factor 2 Dimer Loaded with α-Amanitin and Monomethyl Auristatin E Exhibits Superior Cytotoxicity towards Cancer Cells Overproducing Fibroblast Growth Factor Receptor 1

Dual-payload antibody-drug conjugates: Taking a dual shot

Antibody-drug conjugates (ADCs) enable the precise delivery of cytotoxic agents by conjugating small-molecule drugs with monoclonal antibodies (mAbs). Over recent decades, ADCs have demonstrated substantial clinical efficacy. However, conventional ADCs often encounter various clinical challenges, including suboptimal efficacy, significant adverse effects, and the development of drug resistance, limiting their broader clinical application. Encouragingly, a next-generation approach-dual-payload ADCs-has emerged as a pioneering strategy to address these challenges. Dual-payload ADCs are characterized by the incorporation of two distinct therapeutic payloads on the same antibody, enhancing treatment efficacy by promoting synergistic effects and reducing the risk of drug resistance. However, the synthesis of dual-payload ADCs is complex due to the presence of multiple functional groups on antibodies. In this review, we comprehensively summarize the construction strategies for dual-payload ADCs, ranging from the design of ADC components to orthogonal chemistry. The subsequent sections explore current challenges and propose prospective strategies, highlighting recent advancements in dual-payload ADC research, thereby laying the foundation for the development of next-generation ADCs.

Innovative payloads for ADCs in cancer treatment: moving beyond the selective delivery of chemotherapy

Antibody-drug conjugates (ADCs) have emerged as a transformative approach in cancer therapy by enhancing tumor targeting and minimizing systemic toxicity compared to traditional chemotherapy. Initially developed with chemotherapy agents as payloads, ADCs have now incorporated alternative payloads, such as immune-stimulating agents, natural toxins, and radionuclides, to improve therapeutic efficacy and specificity. A significant advancement in ADC technology is the integration of Proteolysis Targeting Chimeras (PROTACs), which enable the precise degradation of cellular targets involved in tumorigenesis. This strategy enhances the specificity and precision of cancer therapies, addressing key mechanisms in cancer cell survival. Moreover, incorporating radioactive isotopes into ADCs is an emerging strategy aimed at further improving therapeutic outcomes. By delivering localized radiation, this approach offers the potential to enhance the efficacy of treatment and expand the therapeutic arsenal. Despite these innovations, challenges remain, including dysregulated immune activation, severe adverse effects, and intrinsic immunogenicity of some agents. These emerging issues highlight the ongoing need for optimization in ADC therapy. This review summarizes the latest developments in ADC technology, focusing on novel payloads, PROTAC integration, and the potential for combining ADCs with other therapeutic modalities to refine cancer treatment and improve patient outcomes.

Transforming toxins into treatments: the revolutionary role of α-amanitin in cancer therapy

Amanita phalloides is the primary species responsible for fatal mushroom poisoning, as its main toxin, α-amanitin, irreversibly and potently inhibits eukaryotic RNA polymerase II (RNAP II), leading to cell death. There is no specific antidote for α-amanitin, which hinders its clinical application. However, with the advancement of precision medicine in oncology, including the development of antibody-drug conjugates (ADCs), the potential value of various toxic small molecules has been explored. These ADCs ingeniously combine the targeting precision of antibodies with the cytotoxicity of small-molecule payloads to precisely kill tumor cells. We searched PubMed for studies in this area using these MeSH terms "Amanitins, Alpha-Amanitin, Therapeutic use, Immunotherapy, Immunoconjugates, Antibodies" and did not limit the time interval. Recent studies have conducted preclinical experiments on ADCs based on α-amanitin, showing promising therapeutic effects and good tolerance in primates. The current challenges include the not fully understood toxicological mechanism of α-amanitin and the lack of clinical studies to evaluate the therapeutic efficacy of ADCs developed based on α-amanitin. In this article, we will discuss the role and therapeutic efficacy of α-amanitin as an effective payload in ADCs for the treatment of various cancers, providing background information for the research and application strategies of current and future drugs.