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Background: HER3 (ErbB3), a member of the human epidermal growth factor receptor family, is frequently overexpressed in various cancers. Multiple HER3-targeting antibodies and antibody–drug conjugates (ADCs) were developed for the solid tumor treatment, however none of HER3-targeting agent has been approved for tumor therapy yet. We developed DB-1310, a HER3 ADC composed of a novel humanized anti-HER3 monoclonal antibody covalently linked to a proprietary DNA topoisomerase I inhibitor payload (P1021), and evaluate the efficacy and safety of DB-1310 in preclinical models. Methods: The binding of DB-1310 to Her3 and other HER families were measured by ELISA and SPR. The competition of binding epitope for DB-1310 and patritumab was tested by FACS. The sensitivity of breast, lung, prostate and colon cancer cell lines to DB-1310 was evaluated by in vitro cell killing assay. In vivo growth inhibition study evaluated the sensitivity of DB-1310 to Her3 + breast, lung, colon and prostate cancer xenograft models. The safety profile was also measured in cynomolgus monkey. Results: DB-1310 binds HER3 via a novel epitope with high affinity and internalization capacity. In vitro, DB-1310 exhibited cytotoxicity in numerous HER3 + breast, lung, prostate and colon cancer cell lines. In vivo studies in HER3 + HCC1569 breast cancer, NCI-H441 lung cancer and Colo205 colon cancer xenograft models showed DB-1310 to have dose-dependent tumoricidal activity. Tumor suppression was also observed in HER3 + non-small cell lung cancer (NSCLC) and prostate cancer patient-derived xenograft (PDX) models. Moreover, DB-1310 showed stronger tumor growth-inhibitory activity than patritumab deruxtecan (HER3-DXd), which is another HER3 ADC in clinical development at the same dose. The tumor-suppressive activity of DB-1310 synergized with that of EGFR tyrosine kinase inhibitor, osimertinib, and exerted efficacy also in osimertinib-resistant PDX model. The preclinical assessment of safety in cynomolgus monkeys further revealed DB-1310 to have a good safety profile with a highest non severely toxic dose (HNSTD) of 45 mg/kg. Conclusions: These finding demonstrated that DB-1310 exerted potent antitumor activities against HER3 + tumors in in vitro and in vivo models, and showed acceptable safety profiles in nonclinical species. Therefore, DB-1310 may be effective for the clinical treatment of HER3 + solid tumors. [ABSTRACT FROM AUTHOR]

Simple Summary: For nearly half a century, a mainstay and goal of medical oncology has been to identify novel anticancer drugs and therapeutic strategies to promote the effective elimination of cancer cells via apoptosis. In the past decade, however, single cell biology has revealed that apoptosis is not obligatorily a permanent cell fate. The purpose of this commentary is to briefly discuss laboratory and clinical studies that have revealed the dark side of apoptosis in treating patients with solid tumors. Most therapeutic strategies for solid tumor malignancies are designed based on the hypothesis that cancer cells evade apoptosis to exhibit therapy resistance. This is somewhat surprising given that clinical studies published since the 1990s have demonstrated that increased apoptosis in solid tumors is associated with cancer aggressiveness and poor clinical outcome. This is consistent with more recent reports demonstrating non-canonical (pro-survival) roles for apoptotic caspases, including caspase 3, as well as the ability of cancer cells to recover from late stages of apoptosis via a process called anastasis. These activities are essential for the normal development and maintenance of a healthy organism, but they also enable malignant cells (including cancer stem cells) to resist anticancer treatment and potentially contribute to clinical dormancy (minimal residual disease). Like apoptosis, therapy-induced cancer cell dormancy (durable proliferation arrest reflecting various manifestations of genome chaos) is also not obligatorily a permanent cell fate. However, as briefly discussed herein, compelling pre-clinical studies suggest that (reversible) dormancy might be the "lesser evil" compared to treacherous apoptosis. [ABSTRACT FROM AUTHOR]

Elevating intratumoral levels of highly toxic reactive oxygen species (ROS) by nanocatalytic medicine for tumor‐specific therapy without using conventional toxic chemodrugs is recently of considerable interest, which, however, still suffers from less satisfactory therapeutic efficacy due to the relatively poor accumulation at the tumor site and largely blocked intratumoral infiltration of nanomedicines. Herein, an ultrasound (US)‐triggered dual size/charge‐switchable nanocatalytic medicine, designated as Cu‐LDH/HMME@Lips, is constructed for deep solid tumor therapy via catalytic ROS generations. The negatively charged liposome outer‐layer of the nanomedicine enables much‐prolonged blood circulation for significantly enhanced tumoral accumulation, while the positively charged Fenton‐like catalyst Cu‐LDH released from the liposome under the US stimulation demonstrates much enhanced intratumoral penetration via transcytosis. In the meantime, the co‐released sonosensitizer hematoporphyrin monomethyl ether (HMME) catalyze the singlet oxygen (1O2) generation upon the US irradiation, and deep‐tumoral infiltrated Cu‐LDH catalyzes the H2O2 decomposition to produce highly toxic hydroxyl radical (·OH) specifically within the mildly acidic tumor microenvironment (TME). The efficient intratumoral accumulation and penetration via the dual size/charge switching mechanism, and the ROS generations by both sonosensitization and Fenton‐like reactions, ensures the high therapeutic efficacy for the deep tumor therapy by the nanocatalytic medicine. [ABSTRACT FROM AUTHOR]

Simple Summary: Although conventional anti-cancer drugs have been the footstone in the fight against cancer, yet they are far from optimal due to issues related with indiscriminate destruction of normal cells, multidrug resistance, and toxicity, as a result, a more selective therapy is urgently needed. Nanocarriers have been increasingly used in drug delivery, especially in cancer therapy. Nanocarriers can improve the therapeutic effect of drugs in cancer by enhancing the specificity and prolonging the circulating half-life of drugs. The aim of this review is to offer a detailed description of different cytotoxic drug nanocarriers and their recent progress. It is expected that this review will be of help to those who have been seeking new study directions in this field and also ones who are about to start the research on nanocarrier-based drug delivery. Conventional chemotherapy is still an important option of cancer treatment, but it has poor cell selectivity, severe side effects, and drug resistance. Utilizing nanoparticles (NPs) to improve the therapeutic effect of chemotherapeutic drugs has been highlighted in recent years. Nanotechnology dramatically changed the face of oncology by high loading capacity, less toxicity, targeted delivery of drugs, increased uptake to target sites, and optimized pharmacokinetic patterns of traditional drugs. At present, research is being envisaged in the field of novel nano-pharmaceutical design, such as liposome, polymer NPs, bio-NPs, and inorganic NPs, so as to make chemotherapy effective and long-lasting. Till now, a number of studies have been conducted using a wide range of nanocarriers for the treatment of solid tumors including lung, breast, pancreas, brain, and liver. To provide a reference for the further application of chemodrug-loaded nanoformulations, this review gives an overview of the recent development of nanocarriers, and the updated status of their use in the treatment of several solid tumors. [ABSTRACT FROM AUTHOR]