Therapeutic Targets of Monoclonal Antibodies Used in the Treatment of Cancer: Current and Emerging

A virus-inspired RNA mimicry approach for effective cancer immunotherapy

Current cancer treatments, including chemotherapy, surgery, and radiation, often present significant challenges such as severe side effects, drug resistance, and damage to healthy tissues. To address these issues, we introduce a virus-inspired RNA mimicry approach, specifically through the development of uridine-rich nanoparticles (UNPs) synthesized using the rolling circle transcription (RCT) technique. These UNPs are designed to mimic the poly-U tail sequences of viral RNA, effectively engaging RIG-I-like receptors (RLRs) such as MDA5 and LGP2 in cancer cells. Activation of these receptors leads to the upregulation of pro-inflammatory cytokines and the initiation of apoptosis, resulting in targeted cancer cell death. Importantly, this strategy overcomes the limitations of traditional therapies and enhances the effectiveness of existing RIG-I stimulators, such as poly(I:C), which has often exhibited toxicity in clinical settings due to delivery methods. Our in vivo studies further demonstrate the ability of UNPs to significantly reduce tumor growth without adverse effects, highlighting their potential as a novel and effective approach in cancer immunotherapy. This approach offers new therapeutic strategies that leverage the body's innate antiviral mechanisms for cancer treatment.

Evaluation of orphan maintained biological medicinal products in the European Union between 2018 to 2023: a regulatory perspective

OBJECTIVES

Orphan medicinal products (OMPs) authorized by the European Union (EU) benefit from market exclusivity, fee waivers, and national incentives. Maintaining orphan status during a marketing authorization application requires meeting eligibility criteria, especially demonstrating significant benefit (SB), which is challenging. This study identifies key features linked to successful orphan status maintenance for biological OMPs approved in the EU between 2018 and 2023.

METHODS

Data from European public assessment reports and orphan maintenance assessment reports were analyzed.

RESULTS

Among the 50 biological OMP maintained orphan designations, 68.0% had to demonstrate SB over existing treatments, with 91.2% leveraging the clinically relevant advantage area, utilizing better clinical efficacy (83.9%) and efficacy in subpopulations (38.7%) subdomains. However, 32.0% did not need to demonstrate SB due to a lack of alternative treatments, most of which were ultra-orphan drugs. Advanced therapy medicinal products and monoclonal antibodies were the most numerous OMP categories, whereas oncology and immunomodulation were the preferred therapeutic areas.

CONCLUSION

The Orphan Regulation is essential in advancing treatments for rare diseases, fostering innovation while addressing unmet medical needs. Nonetheless, the insufficient return on investment criterion remains underused, whereas refining major contribution to patient care guidelines and incorporating real-world evidence may enhance regulatory evaluations.

Nectin-4: A promising prognostic marker and therapeutic target in cancer

Nectin cell adhesion protein 4 (Nectin-4), a calcium-independent immunoglobulin-like protein, has garnered significant attention in oncology due to its pronounced overexpression in malignant tumors and absence in healthy adult tissues. Elevated levels of Nectin-4 have been implicated in the pathogenesis of various cancers, including lung, breast, and urothelial carcinomas. Notably, Nectin-4 has emerged as a promising serological marker for these malignancies, facilitating early diagnosis and monitoring of disease progression. The clinical relevance of Nectin-4 is underscored by the Food and Drug Administration's approval of enfortumab vedotin (EV), the first antibody-drug conjugate targeting this protein, for the treatment of urothelial carcinoma. Ongoing clinical trials are expanding the therapeutic applications of EV, highlighting the critical role of Nectin-4 in targeted cancer therapy. Furthermore, novel therapeutic agents targeting Nectin-4 are under investigation, offering potential new avenues for cancer treatment. Despite these advancements, the precise molecular mechanisms by which Nectin-4 influences carcinogenesis and tumor progression remain inadequately understood. Challenges such as therapy-related adverse effects and the development of drug resistance further complicate the clinical management of Nectin-4-associated cancers. This review investigates the molecular functions of Nectin-4, emphasizing its diagnostic and prognostic value in cancer. We also explore the landscape of novel drug discoveries targeting Nectin-4 and provide an overview of current clinical trials aimed at utilizing this marker for therapeutic interventions. By elucidating the multifaceted role of Nectin-4 in malignancies, this article aims to advance our understanding and improve the clinical outcomes for patients with Nectin-4 overexpressing tumors.

Facile Rebridging Conjugation Approach to Attain Monoclonal Antibody-Targeted Nanoparticles with Enhanced Antigen Binding and Payload Delivery

Adopting conventional conjugation approaches to construct antibody-targeted nanoparticles (NPs) has demonstrated suboptimal control over the binding orientation and the structural stability of monoclonal antibodies (mAbs). Hitherto, the developed antibody-targeted NPs have shown proof of concept but lack product homogeneity, batch-to-batch reproducibility, and stability, precluding their advancement toward the clinic. To circumvent these limitations and advance toward clinical application, herein, a refined approach based on site-specific construction of mAb-immobilized NPs will be appraised. Initially, the conjugation of atezolizumab (anti-PDL1 antibody, Amab) with polymeric NPs was developed using bis-haloacetamide (BisHalide) rebridging chemistry, followed by click chemistry (NP-Fab BisHalide Ab and NP-Fc BisHalide Ab). For comparison purposes, mAb-immobilized NPs developed utilizing conventional conjugation methods, namely, N-hydroxysuccinimide (NHS) coupling and maleimide chemistry (NP-NHS Ab and NP-Mal Ab), were included. Next, flow cytometry and confocal microscopy experiments evaluated the actively targeted NPs (loaded with fluorescent dye) for cellular binding and uptake. Our results demonstrated the superior and selective binding and uptake of NP-Fab BisHalide Ab and NP-Fc BisHalide Ab into EMT6 cells by 19-fold and 13-fold, respectively. To evaluate the PDL1-dependent cell uptake and the selectivity of the treatments, a blocking step of the PDL1 receptor with Amab was performed prior to incubation with NP-Fab BisHalide Ab and NP-Fc BisHalide Ab. To our delight, the binding and uptake of fluorescent NPs were reduced significantly by 3-fold for NP-Fab BisHalide Ab, demonstrating the PDL1-mediated uptake. Moreover, NP-Fab BisHalide Ab and NP-Fc BisHalide Ab were entrapped with the paclitaxel payload, and their cytotoxicity was evaluated. They showed significant enhancements compared to free paclitaxel and NP-NHS Ab. Overall, this work will provide a facile conjugation method that could be implemented to actively target NPs with a plethora of therapeutic mAbs approved for various malignancies.

Treatment patterns and factors associated with discontinuation of monoclonal antibodies

Background

Biological agents have revolutionized care in specialties such as oncology, immunology, infectious diseases, and genetic disorders, offering targeted actions on specific molecules or select immune cells. Monoclonal antibodies, known for their high specificity and precision, represent one of the most significant and rapidly expanding categories of these agents. Understanding the drug utilization patterns of monoclonal antibodies is crucial to ensure their optimal use, especially given their high cost and potential adverse effects.

Methods

This analytical cross-sectional study was conducted in a secondary hospital in the United Arab Emirates. Patients of either gender receiving monoclonal antibodies at the study site were included. Treatment patterns, utilization, and factors associated with the discontinuation of monoclonal antibodies were assessed.

Results

Hyperlipidemia (136, 39.1%) was the most common indication for monoclonal antibodies, followed by prophylaxis of respiratory syncytial virus infection in congenital heart disease (104, 29.9%) and osteoporosis (42, 12.1%). Evolocumab was the most commonly prescribed monoclonal antibody (135, 38.8%), followed by palivizumab (104, 29.9%), and dupilumab (38, 10.9%). The majority of monoclonal antibodies demonstrated a prescribed daily dose to defined daily dose ratio of 1.0, reflecting their appropriate utilization. One hundred twenty-nine patients (37.0%) discontinued their treatment during the study. Patient's level of education (OR: 0.416, 95% CI: 0.183-0.943, p = 0.036), BMI (OR: 2.358, 95% CI: 1.164-4.777, p = 0.017), number of concomitant medications (OR: 2.457, 95% CI: 1.202-5.025, p = 0.014), and treatment duration (OR: 9.180, 95% CI: 4.909-17.165, p < 0.001) were identified as predictors of discontinuation of monoclonal antibodies.

Conclusion

This study represents the first comprehensive investigation in the United Arab Emirates focused on treatment patterns, utilization, and discontinuation of monoclonal antibodies among the local population. Monoclonal antibodies were prescribed for the management of a wide range of clinical conditions. The study reports appropriate utilization of most monoclonal antibodies and identifies factors such as patient education level, BMI, concomitant medications, and treatment duration as independent predictors of monoclonal antibody treatment discontinuation.

Construction of a Human Immune Library from Gallbladder Cancer Patients for the Single-Chain Fragment Variable (scFv) Antibody Selection against Claudin 18.2 via Phage Display

Gallbladder cancer (GBC) is a very aggressive malignant neoplasm of the biliary tract with a poor prognosis. There are no specific therapies for the treatment of GBC or early diagnosis tools; for this reason, the development of strategies and technologies that facilitate or allow an early diagnosis of GBC continues to be decisive. Phage display is a robust technique used for the production of monoclonal antibodies (mAbs) involving (1) the generation of gene libraries, (2) the screening and selection of isoforms related to an immobilized antigen, and (3) the in vitro maturation of the affinity of the antibody for the antigen. This research aimed to construct a human immune library from PBMCs of GBC patients and the isolation of scFv-phage clones with specificity against the larger extracellular loop belonging to claudin 18.2, which is an important biomarker overexpressed in GBC as well as gastric cancer. The immune-library-denominated GALLBLA1 was constructed from seven GBC patients and has a diversity of 6.12 × 1010pfu mL-1. After three rounds of panning, we were able to identify clones with specificity against claudin 18.2. GALLBLA1 can contribute to the selection, isolation, and recombinant production of new human mAbs candidates for the treatment of gastrointestinal cancers.

Emicizumab as a Promising Form of Therapy for Type A Hemophilia - A Review of Current Knowledge from Clinical Trials

Hemophilia is a plasma bleeding disorder characterized by a deficiency of certain blood clotting factors. The most common forms of this disease, i.e., type A and type B, affect approximately 400,000 people worldwide. Without appropriate treatment ensuring the proper coagulation cascade, this disease may lead to serious disability. Minimizing patient discomfort is possible via replacement therapy, consisting of the substitution of a missing coagulation factor via intravenous administration. Frequent medication and the risk related to factor inhibitors are significant disadvantages, necessitating the improvement of current therapies or the development of novel ones. This review examines the humanized bispecific antibody Emicizumab which ensures hemostasis by mimicking the action of the coagulation factor VIII, a deficiency of which causes type A hemophilia. The paper outlines the topic and then summarizes available clinical trials on Emicizumab in type A hemophilia. Several interventional clinical trials have found Emicizumab to be effective in decreasing bleeding episodes and raising patient satisfaction among various hemophilia A populations. Current Emicizumab-related trials are forecast to be completed between 2024 and 2030, and in addition to congenital hemophilia A, the trials cover acquired hemophilia A and patients playing sports. Providing a more comprehensive understanding of Emicizumab may revolutionize the management of hemophilia type A and improve quality of life. Conclusively, Emicizumab is a gentler therapy owing to subcutaneous delivery and fewer injections, which reduces injection-site reactions and makes therapy less burdensome, ultimately decreasing hospital visits and indirect costs.

Nectin-4 has emerged as a compelling target for breast cancer

The incidence of breast cancer in women has increased year by year, becoming one of the most common malignant tumors in females worldwide. Most patients can be treated with surgery and endocrine drugs, but there are still some patients who lack effective treatment, such as triple-negative breast cancer (TNBC). Nectin-4, a protein encoded by poliovirus receptor-associated protein 4, is a Ca2+-independent immunoglobulin-like protein. It is mainly involved in the adhesion between cells. In recent years, studies have found that Nectin-4 is overexpressed in breast cancer and several other malignancies. Otherwise, several monoclonal antibodies and inhibitors targeting Nectin-4 have shown prosperous outcomes, so Nectin-4 has great potential to be a therapeutic target for breast cancer. The present review systematically describes the significance of Nectin-4 in each aspect of breast cancer, as well as the molecular mechanisms of these aspects mediated by Nectin-4. We further highlight ongoing or proposed therapeutic strategies for breast cancer specific to Nectin-4.