Erythrocyte-encapsulated asparaginase (eryaspase) combined with chemotherapy in second-line treatment of advanced pancreatic cancer: An open-label, randomized Phase IIb trial

The unique metabolome of clear cell ovarian carcinoma

Clear cell ovarian carcinoma (CCOC) is an aggressive malignancy affecting younger women. Despite ovarian cancer subtypes having diverse molecular and clinical characteristics, the mainstay of treatment for advanced stage disease remains cytotoxic chemotherapy. Late stage CCOC is resistant to conventional chemotherapy, which means a suboptimal outcome for patients affected. Despite detailed genomic, epigenomic, transcriptomic, and proteomic characterisation, subtype-specific treatment for CCOC has shown little progress. The unique glycogen accumulation defining CCOC suggests altered metabolic pathway activity and dependency. This study presents the first metabolomic landscape of ovarian cancer subtypes, including 42 CCOC, 20 high-grade serous and 21 endometrioid ovarian carcinomas, together comprising the three most common ovarian carcinoma subtypes. We describe a distinct metabolomic landscape of CCOC compared with other ovarian cancer subtypes, including alterations in energy utilisation and cysteine metabolism. In addition, we identify CCOC-specific alterations in metabolic pathways including serine biosynthesis and ROS-associated pathways that could serve as potential therapeutic targets. Our study provides the first in-depth study into the metabolome of ovarian cancers and a rich resource to support ongoing research efforts to identify subtype-specific therapeutic targets that could improve the dismal outcome for patients with this devastating malignancy. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Nano- and Micro-Platforms in Therapeutic Proteins Delivery for Cancer Therapy: Materials and Strategies

Proteins have emerged as promising therapeutics in oncology due to their great specificity. Many treatment strategies are developed based on protein biologics, such as immunotherapy, starvation therapy, and pro-apoptosis therapy, while some protein biologics have entered the clinics. However, clinical translation is severely impeded by instability, short circulation time, poor transmembrane transportation, and immunogenicity. Micro- and nano-particles-based drug delivery platforms are designed to solve those problems and enhance protein therapeutic efficacy. This review first summarizes the different types of therapeutic proteins in clinical and research stages, highlighting their administration limitations. Next, various types of micro- and nano-particles are described to demonstrate how they can overcome those limitations. The potential of micro- and nano-particles are then explored to enhance the therapeutic efficacy of proteins by combinational therapies. Finally, the challenges and future directions of protein biologics carriers are discussed for optimized protein delivery.

Differential effect of asparagine and glutamine removal on three adenocarcinoma cell lines

Asparagine and glutamine depletion operated by the drug Asparaginase (ASNase) has revolutionized therapy in pediatric patients affected by Acute Lymphoblastic Leukemia (ALL), bringing remissions to a remarkable 90 % of cases. However, the knowledge of the proproliferative role of asparagine in adult and solid tumors is still limited. We have here analyzed the effect of ASNase on three adenocarcinoma cell lines (A549, lung adenocarcinoma, MCF-7, breast cancer, and 786-O, kidney cancer). In contrast to MCF-7 cells, 786-O and A549 cells proved to be a relevant target for cell cycle perturbation by asparagine and glutamine shortage. Indeed, when the cell-cycle was analyzed by flow cytometry, A549 showed a canonical response to asparaginase, 786-O cells, instead, showed a reduction of the percentage of cells in the G1 phase and an increase of those in the S-phase. Despite an increased number of PCNA and RPA70 positive nuclear foci, BrdU and EdU incorporation was absent or strongly delayed in treated 786-O cells, thus indicating a readiness of replication forks unmatched by DNA synthesis. In 786-O asparagine synthetase was reduced following treatment and glutamine synthetase was totally absent. Interestingly, DNA synthesis could be recovered by adding Gln to the medium. MCF-7 cells showed no significant changes in the cell cycle phases, in DNA-bound PCNA and in total PCNA, but a significant increase in ASNS and GS mRNA and protein expression. The collected data suggest that the effect observed on 786-O cells following ASNase treatment could rely on mechanisms which differ from those well-known and described for leukemic blasts, consisting of a complete block in the G1/S transition in proliferating cells and on an increase on non-proliferative (G0) blasts.

Emerging mechanisms and promising approaches in pancreatic cancer metabolism

Pancreatic cancer is an aggressive cancer with a poor prognosis. Metabolic abnormalities are one of the hallmarks of pancreatic cancer, and pancreatic cancer cells can adapt to biosynthesis, energy intake, and redox needs through metabolic reprogramming to tolerate nutrient deficiency and hypoxic microenvironments. Pancreatic cancer cells can use glucose, amino acids, and lipids as energy to maintain malignant growth. Moreover, they also metabolically interact with cells in the tumour microenvironment to change cell fate, promote tumour progression, and even affect immune responses. Importantly, metabolic changes at the body level deserve more attention. Basic research and clinical trials based on targeted metabolic therapy or in combination with other treatments are in full swing. A more comprehensive and in-depth understanding of the metabolic regulation of pancreatic cancer cells will not only enrich the understanding of the mechanisms of disease progression but also provide inspiration for new diagnostic and therapeutic approaches.

Engineering of Erythrocytes as Drug Carriers for Therapeutic Applications

Erythrocytes, also known as red blood cells (RBCs), have garnered considerable attention as potential carriers for drug delivery, owing to their inherent properties such as biocompatibility, biodegradability, and prolonged circulation half-life. This paper presents a comprehensive overview of the role of erythrocytes in drug delivery, elucidating recent advancements in delivering a diverse array of therapeutic agents, including small molecules, nucleic acids, antibodies, protein enzymes, and nanoparticles. Two primary strategies for encapsulating drugs within erythrocytes are systematically discussed: internal loading and surface loading. Each strategy offers distinct advantages in terms of drug stability and release kinetics. Notably, the utilization of erythrocyte membrane camouflaged nanocarriers holds promise for enhancing the biocompatibility of conventional nanoparticles and facilitating targeted drug delivery. Furthermore, the broad spectrum of biomedical applications of erythrocyte-based drug delivery systems are examined, ranging from cancer treatment to diabetes management, thrombosis prevention, and immunotherapy. This review provides a comprehensive evaluation of current technologies in erythrocyte-loaded drug delivery, highlighting the strengths, weaknesses, and future directions for advancing therapeutic interventions in various disease contexts.

Protein nanoparticles as drug delivery systems for cancer theranostics

Protein-based nanoparticles have garnered significant attention in theranostic applications due to their superior biocompatibility, exceptional biodegradability and ease of functionality. Compared to other nanocarriers, protein-based nanoparticles offer additional advantages, including biofunctionality and precise molecular recognition abilities, which make them highly effective in navigating complex biological environments. Moreover, proteins can serve as powerful tools with self-assembling structures and reagents that enhance cell penetration. And their derivation from abundant renewable sources and ability to degrade into harmless amino acids further enhance their suitability for biomedical applications. However, protein-based nanoparticles have so far not realized their full potential. In this review, we summarize recent advances in the use of protein nanoparticles in tumor diagnosis and treatment and outline typical methods for preparing protein nanoparticles. The review of protein nanoparticles may provide useful new insights into the development of biomaterial fabrication.

The Cancer Antioxidant Regulation System in Therapeutic Resistance

Antioxidants play a pivotal role in neutralizing reactive oxygen species (ROS), which are known to induce oxidative stress. In the context of cancer development, cancer cells adeptly maintain elevated levels of both ROS and antioxidants through a process termed "redox reprogramming". This balance optimizes the proliferative influence of ROS while simultaneously reducing the potential for ROS to cause damage to the cell. In some cases, the adapted antioxidant machinery can hamper the efficacy of treatments for neoplastic diseases, representing a significant facet of the resistance mechanisms observed in cancer therapy. In this review, we outline the contribution of antioxidant systems to therapeutic resistance. We detail the fundamental constituents of these systems, encompassing the central regulatory mechanisms involving transcription factors (of particular importance is the KEAP1/NRF2 signaling axis), the molecular effectors of antioxidants, and the auxiliary systems responsible for NADPH generation. Furthermore, we present recent clinical trials based on targeted antioxidant systems for the treatment of cancer, assessing the potential as well as challenges of this strategy in cancer therapy. Additionally, we summarize the pressing issues in the field, with the aim of illuminating a path toward the emergence of novel anticancer therapeutic approaches by orchestrating redox signaling.

Exploiting pancreatic cancer metabolism: challenges and opportunities

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive form of pancreatic cancer, known for its challenging diagnosis and limited treatment options. The focus on metabolic reprogramming as a key factor in tumor initiation, progression, and therapy resistance has gained prominence. In this review we focus on the impact of metabolic changes on the interplay among stromal, immune, and tumor cells, as glutamine and branched-chain amino acids (BCAAs) emerge as pivotal players in modulating immune cell functions and tumor growth. We also discuss ongoing clinical trials that explore metabolic modulation for PDAC, targeting mitochondrial metabolism, asparagine and glutamine addiction, and autophagy inhibition. Overcoming challenges in understanding nutrient effects on immune-stromal-tumor interactions holds promise for innovative therapeutic strategies.

Efferocytosis by macrophages in physiological and pathological conditions: regulatory pathways and molecular mechanisms

Efferocytosis is defined as the highly effective phagocytic removal of apoptotic cells (ACs) by professional or non-professional phagocytes. Tissue-resident professional phagocytes ("efferocytes"), such as macrophages, have high phagocytic capacity and are crucial to resolve inflammation and aid in homeostasis. Recently, numerous exciting discoveries have revealed divergent (and even diametrically opposite) findings regarding metabolic immune reprogramming associated with efferocytosis by macrophages. In this review, we highlight the key metabolites involved in the three phases of efferocytosis and immune reprogramming of macrophages under physiological and pathological conditions. The next decade is expected to yield further breakthroughs in the regulatory pathways and molecular mechanisms connecting immunological outcomes to metabolic cues as well as avenues for "personalized" therapeutic intervention.

Second-Line Treatment of Pancreatic Adenocarcinoma: Shedding Light on New Opportunities and Key Talking Points from Clinical Trials

Despite improvements in overall cancer mortality, deaths related to pancreatic cancer continue to rise. Following first-line treatment, second-line options are significantly limited. Classically, first-line treatment consisted of either gemcitabine or 5-fluorouracil based systemic chemotherapy. Upon progression of disease or recurrence, subsequent second-line treatment is still gemcitabine or 5-fluorouracil based chemotherapy, depending on what was used in the first line and the timing of progression or recurrence. A better understanding of the molecular underpinnings of pancreatic adenocarcinoma (PDAC) has led to new treatment strategies including specifically targeting the desmoplastic stroma, cytokine signaling and actionable mutations. Furthermore, efforts are also directed to enhance the immunogenicity profile of PDAC's well-established immunologically "cold" tumor microenvironment. More recently, the outstanding response rates of chimeric antigen receptor T (CAR-T) cells in hematologic malignancies, have led to clinical trials to evaluate the treatment modality in PDAC. In this review, we summarize recently presented clinical trials for metastatic pancreatic adenocarcinoma with novel treatment approaches in the second line and beyond.

Cell-nanocarrier drug delivery system: a promising strategy for cancer therapy

Tumor targeting has been a great challenge for drug delivery systems. A number of nanotechnology-derived drug carriers have been developed for cancer treatment to improve efficacy and biocompatibility. Among them, the emergence of cell-nanocarriers has attracted great attention, which simulates cell function and has good biocompatibility. They can also escape the clearance of reticuloendothelial system, showing a long-cycle effect. The inherent tumor migration and tumor homing ability of cells increase their significance as tumor-targeting vectors. In this review, we focus on the combination of stem cells, immune cells, red blood cells, and cell membranes to nanocarriers, which enable chemotherapy agents to efficiently target lesion sites and improve drug distribution while being low toxic and safe. In addition, we discuss the pros and cons of these nanoparticles as well as the challenges and opportunities that lie ahead. Although research to address these limitations is still ongoing, this promising tumor-targeted drug delivery system will provide a safe and effective platform against cancer.

Targeting cancer metabolic pathways for improving chemotherapy and immunotherapy

Recent discoveries in cancer metabolism have revealed promising metabolic targets to modulate cancer progression, drug response, and anti-cancer immunity. Combination therapy, consisting of metabolic inhibitors and chemotherapeutic or immunotherapeutic agents, offers new opportunities for improved cancer therapy. However, it also presents challenges due to the complexity of cancer metabolic pathways and the metabolic interactions between tumor cells and immune cells. Many studies have been published demonstrating potential synergy between novel inhibitors of metabolism and chemo/immunotherapy, yet our understanding of the underlying mechanisms remains limited. Here, we review the current strategies of altering the metabolic pathways of cancer to improve the anti-cancer effects of chemo/immunotherapy. We also note the need to differentiate the effect of metabolic inhibition on cancer cells and immune cells and highlight nanotechnology as an emerging solution. Improving our understanding of the complexity of the metabolic pathways in different cell populations and the anti-cancer effects of chemo/immunotherapy will aid in the discovery of novel strategies that effectively restrict cancer growth and augment the anti-cancer effects of chemo/immunotherapy.

L-asparaginase anti-tumor activity in pancreatic cancer is dependent on its glutaminase activity and resistance is mediated by glutamine synthetase

l-Asparaginase is a cornerstone of acute lymphoblastic leukemia (ALL) therapy since lymphoblasts lack asparagine synthetase (ASNS) and rely on extracellular asparagine availability for survival. Resistance mechanisms are associated with increased ASNS expression in ALL. However, the association between ASNS and l-Asparaginase efficacy in solid tumors remains unclear, thus limiting clinical development. Interestingly, l-Asparaginase also has a glutaminase co-activity that is crucial in pancreatic cancer where KRAS mutations activate glutamine metabolism. By developing l-Asparaginase-resistant pancreatic cancer cells and using OMICS approaches, we identified glutamine synthetase (GS) as a marker of resistance to l-Asparaginase. GS is the only enzyme able to synthesize glutamine, and its expression also correlates with l-Asparaginase efficacy in 27 human cell lines from 11 cancer indications. Finally, we further demonstrated that GS inhibition prevents cancer cell adaptation to l-Asparaginase-induced glutamine starvation. These findings could pave the way to the development of promising drug combinations to overcome l-Asparaginase resistance.

Engineering cells for precision drug delivery: New advances, clinical translation, and emerging strategies

Cells have emerged as a promising new form of drug delivery carriers owing to their distinguished advantages such as naturally bypassing immune recognition, intrinsic capability to navigate biological barriers, and access to hard-to-reach tissues via onboarding sensing and active motility. Over the past two decades, a large body of work has focused on understanding the ability of cell carriers to breach biological barriers and to modulate drug pharmacokinetics and pharmacodynamics. These efforts have led to the engineering of various cells for tissue-specific drug delivery. Despite exciting advances, clinical translation of cell-based drug carriers demands a thorough understanding of the pressing challenges and potential strategies to overcome them. Here, we summarize recent advances and new concepts in cell-based drug carriers and their clinical translation. We also discuss key considerations and emerging strategies to engineering the next-generation cell-based delivery technologies for more precise, targeted drug delivery.

The role of amino acid metabolism alterations in pancreatic cancer: From mechanism to application

The incidence of pancreatic cancer is increasing in both developed and developing Nations. In recent years, various research evidence suggested that reprogrammed metabolism may play a key role in pancreatic cancer tumorigenesis and development. Therefore, it has great potential as a diagnostic, prognostic and therapeutic target. Amino acid metabolism is deregulated in pancreatic cancer, and changes in amino acid metabolism can affect cancer cell status, systemic metabolism in malignant tumor patients and mistakenly involved in different biological processes including stemness, proliferation and growth, invasion and migration, redox state maintenance, autophagy, apoptosis and even tumor microenvironment interaction. Generally, the above effects are achieved through two pathways, energy metabolism and signal transduction. This review aims to highlight the current research progress on the abnormal alterations of amino acids metabolism in pancreatic cancer, how they affect tumorigenesis and development of pancreatic cancer and the application prospects of them as diagnostic, prognostic and therapeutic targets.

Efficacy and tolerance of LV5FU2-carboplatin chemotherapy in patients with advanced pancreatic ductal adenocarcinoma after failure of standard regimens

Background:

Chemotherapy options in patients with advanced pancreatic ductal adenocarcinoma (PDAC) after failure of standard chemotherapies are limited.

Objectives:

We aimed to report the efficacy and safety of the leucovorin and 5-fluorouracil (LV5FU2) and carboplatin combination in this setting.

Design:

We performed a retrospective study including consecutive patients with advanced PDAC who received LV5FU2–carboplatin between 2009 and 2021 in an expert center.

Methods:

We measured overall survival (OS) and progression-free survival (PFS), and explored associated factors using Cox proportional hazard models.

Results:

In all, 91 patients were included (55% male, median age 62), with a performance status of 0/1 in 74% of cases. LV5FU2–carboplatin was mainly used in third (59.3%) or fourth line (23.1%), with three (interquartile range: 2.0–6.0) cycles administered on average. The clinical benefit rate was 25.2%. Median PFS was 2.7 months (95% CI: 2.4–3.0). At multivariable analysis, no extrahepatic metastases (p = 0.083), no ascites or opioid-requiring pain (p = 0.023), <2 prior treatment lines (p < 0.001), full dose of carboplatin (p = 0.004), and treatment initiation >18 months after initial diagnosis (p < 0.001) were associated with longer PFS. Median OS was 4.2 months (95% CI: 3.48–4.92) and was influenced by the presence of extrahepatic metastases (p = 0.058), opioid-requiring pain or ascites (p = 0.039), and number of prior treatment lines (0.065). Prior tumor response under oxaliplatin did not impact either PFS or OS. Worsening of preexisting residual neurotoxicity was infrequent (13.2%). The most common grade 3–4 adverse events were neutropenia (24.7%) and thrombocytopenia (11.8%).

Conclusion:

Although the efficacy of LV5FU2–carboplatin appears limited in patients with pretreated advanced PDAC, it may be beneficial in selected patients.

Second-line treatment options for patients with metastatic pancreatic ductal adenocarcinoma: A systematic literature review

INTRODUCTION

The aim of this review was to characterize the second- and later-line (≥2L) treatment landscape for patients with metastatic pancreatic ductal adenocarcinoma (mPDAC).

METHODS

This systematic literature review (PROSPERO: CRD42021279753) involved searches of MEDLINE® and Embase to identify results from prospective studies of ≥2L treatment options for metastatic pancreatic cancer published from 2016 to 2021. Publications were screened according to predetermined eligibility criteria; population-level data were extracted using standardized data fields. Publication quality was assessed according to Grading of Recommendations Assessment, Development and Evaluation (GRADE). The data were analyzed descriptively, grouped by drug class.

RESULTS

Sixty publications were identified, including 23 relating to comparative trials. GRADE assessment found that, of these 23 trials, 83% reported high or moderate-quality evidence. Of the publications relating to comparative trials, nine (three trials) reported favorable results: the pivotal phase 3 NAPOLI-1 trial for liposomal irinotecan; a phase 3 trial of non-liposomal irinotecan within the FOLFIRINOX regimen; and a phase 2 trial of eryaspase plus chemotherapy.

CONCLUSIONS

The level of unmet need for ≥2L treatment options for mPDAC remains high. Irinotecan-based regimens currently offer the greatest promise. Investigations into paradigm-changing agents and combination approaches continue.

Design of erythrocyte-derived carriers for bioimaging applications

Erythrocytes are physiological entities that have been exploited in both preclinical and clinical trials for the delivery of exogenous agents. Over the years, diverse erythrocyte-derived carriers (ECs) have been developed with related patents granted for industrial and commercial purposes. However, most ECs have only been exploited for drug delivery. Serious discussions regarding their applications in imaging are scarce. This article reviews the role of ECs in enhancing imaging efficiency and subsequently delineates strategies for engineering and optimising their preclinical and clinical performance. With a snapshot of the latest developments and use of ECs in imaging, directions to streamline the clinical translation of related technologies can be attained for future research.

A randomized phase II study of SM-88 plus methoxsalen, phenytoin, and sirolimus in patients with metastatic pancreatic cancer treated in the second line and beyond

BACKGROUND

This trial explores SM-88 used with methoxsalen, phenytoin, and sirolimus (MPS) in pretreated metastatic pancreatic ductal adenocarcinoma (mPDAC) METHODS: Forty-nine patients were randomized to daily 460 or 920 mg oral SM-88 with MPS (SM-88 Regimen). The primary endpoint was objective response rate (RECIST 1.1).

RESULTS

Thirty-seven patients completed ≥ one cycle of SM-88 Regimen (response evaluable population). Disease control rate (DCR), overall survival (OS), and progression-free survival (PFS) did not differ significantly between dose levels. Stable disease was achieved in 9/37 patients (DCR, 24.3%); there were no complete or partial responses. Quality-of-life (QOL) was maintained and trended in favor of 920 mg. SM-88 Regimen was well tolerated; a single patient (1/49) had related grade 3 and 4 adverse events, which later resolved. In the intention-to-treat population of 49 patients, the median overall survival (mOS) was 3.4 months (95% CI: 2.7-4.9 months). Those treated in the second line had an mOS of 8.1 months and a median PFS of 3.8 months. Survival was higher for patients with stable versus progressive disease (any line; mOS: 10.6 months vs. 3.9 months; p = 0.01).

CONCLUSIONS

SM-88 Regimen has a favorable safety profile with encouraging QOL effects, disease control, and survival trends. This regimen should be explored in the second-line treatment of patients with mPDAC.

CLINICALTRIALS

gov Identifier: NCT03512756.

Differential integrated stress response and asparagine production drive symbiosis and therapy resistance of pancreatic adenocarcinoma cells

The pancreatic tumor microenvironment drives deregulated nutrient availability. Accordingly, pancreatic cancer cells require metabolic adaptations to survive and proliferate. Pancreatic cancer subtypes have been characterized by transcriptional and functional differences, with subtypes reported to exist within the same tumor. However, it remains unclear if this diversity extends to metabolic programming. Here, using metabolomic profiling and functional interrogation of metabolic dependencies, we identify two distinct metabolic subclasses among neoplastic populations within individual human and mouse tumors. Furthermore, these populations are poised for metabolic cross-talk, and in examining this, we find an unexpected role for asparagine supporting proliferation during limited respiration. Constitutive GCN2 activation permits ATF4 signaling in one subtype, driving excess asparagine production. Asparagine release provides resistance during impaired respiration, enabling symbiosis. Functionally, availability of exogenous asparagine during limited respiration indirectly supports maintenance of aspartate pools, a rate-limiting biosynthetic precursor. Conversely, depletion of extracellular asparagine with PEG-asparaginase sensitizes tumors to mitochondrial targeting with phenformin.

Translational alterations in pancreatic cancer: a central role for the integrated stress response

mRNA translation is a key mechanism for cancer cell proliferation and stress adaptation. Regulation of this machinery implicates upstream pathways such as PI3K/AKT/mTOR, RAS/MEK/ERK and the integrated stress response (ISR), principally coordinating the translation initiation step. During the last decade, dysregulation of the mRNA translation process in pancreatic cancer has been widely reported, and shown to critically impact on cancer initiation, development and survival. This includes translation dysregulation of mRNAs encoding oncogenes and tumor suppressors. Hence, cancer cells survive a stressful microenvironment through a flexible regulation of translation initiation for rapid adaptation. The ISR pathway has an important role in chemoresistance and shows high potential therapeutic interest. Despite the numerous translational alterations reported in pancreatic cancer, their consequences are greatly underestimated. In this review, we summarize the different translation dysregulations described in pancreatic cancer, which make it invulnerable, as well as the latest drug discoveries bringing a glimmer of hope.

Targeting amino acid metabolism in cancer

Metabolic rewiring is a characteristic hallmark of cancer cells. This phenomenon sustains uncontrolled proliferation and resistance to apoptosis by increasing nutrients and energy supply. However, reprogramming comes together with vulnerabilities that can be used against tumor and can be applied in targeted therapy. In the last years, the genetic background of tumors has been identified thoroughly and new therapies targeting those mutations tested. Nevertheless, we propose that targeting the phenotype of cancer cells could be another way of treatment aiming to avoid drug resistance and non-responsiveness of cancer patients. Amino acid metabolism is part of the altered processes in cancer cells. Amino acids are building blocks and also sensors of signaling pathways regulating main biological processes. In this comprehensive review, we described four amino acids (asparagine, arginine, methionine, and cysteine) which have been actively investigated as potential targets for anti-tumor therapy. Asparagine depletion is successfully used for decades in the treatment of acute lymphoblastic leukemia and there is a strong implication to apply it to other types of tumors. Arginine auxotrophic tumors are great candidates for arginine-starvation therapy. Higher requirement for essential amino acids such as methionine and cysteine point out promising targetable weaknesses of cancer cells.

Therapeutic advances in metastatic pancreatic cancer: a focus on targeted therapies

Mortality from pancreatic ductal adenocarcinoma (PDAC) is increasing worldwide and effective new treatments are urgently needed. The current treatment of metastatic PDAC in fit patients is based on two chemotherapy combinations (FOLFIRINOX and gemcitabine plus nab-paclitaxel) which were validated more than 8 years ago. Although almost all treatments targeting specific molecular alterations have failed so far when administered to unselected patients, encouraging results were observed in the small subpopulations of patients with germline BRCA 1/2 mutations, and somatic gene fusions (neurotrophic tyrosine receptor kinase, Neuregulin 1, which are enriched in KRAS wild-type PDAC), KRAS G12C mutations, or microsatellite instability. While targeted tumor metabolism therapies and immunotherapy have been disappointing, they are still under investigation in combination with other drugs. Optimizing pharmacokinetics and adapting available chemotherapies based on molecular signatures are other promising avenues of research. This review evaluates the current expectations and limits of available treatments and analyses the existing trials. A permanent search for actionable vulnerabilities in PDAC tumor cells and microenvironments will probably result in a more personalized therapeutic approach, keeping in mind that supportive care must also play a major role if real clinical efficacy is to be achieved in these patients.

Moving the Needle on Precision Medicine in Pancreatic Cancer

The management of pancreatic ductal adenocarcinoma (PDAC) has posed a considerable challenge for decades, with incidence and mortality rates almost mirroring each other. Despite this, a deeper understanding of the complex biology inherent to PDAC has provided a roadmap for a more precise approach to treatment. PDAC deficient in homologous recombination repair and mismatch repair is a subgroup that should be identified in the clinic for a targeted approach. In addition, KRAS wild-type PDAC, occurring in approximately 10% of patients, is enriched in highly actionable alterations including fusions, underscoring the importance of integrative germline and somatic sequencing. Comprehensive sequencing efforts over the past decade have documented genomic- and transcriptomic-based classifiers, with the latter emerging as two main subtypes: the classical and basal-like, which are now being evaluated in clinical trials. Together with promising, innovative strategies to target KRAS mutations and their pleotropic effects, a new era of precision medicine in PDAC is on the horizon.

Amino acid metabolism: challenges and opportunities for the therapeutic treatment of leukemia and lymphoma

Leukemia and lymphoma-the most common hematological malignant diseases-are often accompanied by complications such as drug resistance, refractory diseases and relapse. Amino acids (AAs) are important energy sources for malignant cells. Tumor-mediated AA metabolism is associated with the immunosuppressive properties of the tumor microenvironment, thereby assisting malignant cells to evade immune surveillance. Targeting abnormal AA metabolism in the tumor microenvironment may be an effective therapeutic approach to address the therapeutic challenges of leukemia and lymphoma. Here, we review the effects of glutamine, arginine and tryptophan metabolism on tumorigenesis and immunomodulation, and define the differences between tumor cells and immune effector cells. We also comment on treatments targeting these AA metabolism pathways in lymphoma and leukemia and discuss how these treatments have profound adverse effects on tumor cells, but leave the immune cells unaffected or mildly affected.

Red Blood Cell Inspired Strategies for Drug Delivery: Emerging Concepts and New Advances

In the past five decades, red blood cells (RBCs) have been extensively explored as drug delivery systems due to their distinguishing potential in modulating the pharmacokinetic, pharmacodynamics, and biological activity of carried payloads. The extensive interests in RBC-mediated drug delivery technologies are in part derived from RBCs' unique biological features such as long circulation time, wide access to many tissues in the body, and low immunogenicity. Owing to these outstanding properties, a large body of efforts have led to the development of various RBC-inspired strategies to enable precise drug delivery with enhanced therapeutic efficacy and reduced off-target toxicity. In this review, we discuss emerging concepts and new advances in such RBC-inspired strategies, including native RBCs, ghost RBCs, RBC-mimetic nanoparticles, and RBC-derived extracellular vesicles, for drug delivery.

Current Use of Asparaginase in Acute Lymphoblastic Leukemia/Lymphoblastic Lymphoma

Pediatric Acute Lymphoblastic Leukemia (ALL) cure rates have improved exponentially over the past five decades with now over 90% of children achieving long-term survival. A direct contributor to this remarkable feat is the development and expanded understanding of combination chemotherapy. Asparaginase is the most recent addition to the ALL chemotherapy backbone and has now become a hallmark of therapy. It is generally accepted that the therapeutic effects of asparaginase is due to depletion of the essential amino acid asparagine, thus occupying a unique space within the therapeutic landscape of ALL. Pharmacokinetic and pharmacodynamic profiling have allowed a detailed and accessible insight into the biochemical effects of asparaginase resulting in regular clinical use of therapeutic drug monitoring (TDM). Asparaginase's derivation from bacteria, and in some cases conjugation with a polyethylene glycol (PEG) moiety, have contributed to a unique toxicity profile with hypersensitivity reactions being the most salient. Hypersensitivity, along with several other toxicities, has limited the use of asparaginase in some populations of ALL patients. Both TDM and toxicities have contributed to the variety of approaches to the incorporation of asparaginase into the treatment of ALL. Regardless of the approach to asparagine depletion, it has continually demonstrated to be among the most important components of ALL therapy. Despite regular use over the past 50 years, and its incorporation into the standard of care treatment for ALL, there remains much yet to be discovered and ample room for improvement within the utilization of asparaginase therapy.

Chemical Conjugation in Drug Delivery Systems

Cancer is one of the diseases with the highest mortality rate. Treatments to mitigate cancer are usually so intense and invasive that they weaken the patient to cure as dangerous as the own disease. From some time ago until today, to reduce resistance generated by the constant administration of the drug and improve its pharmacokinetics, scientists have been developing drug delivery system (DDS) technology. DDS platforms aim to maximize the drugs’ effectiveness by directing them to reach the affected area by the disease and, therefore, reduce the potential side effects. Erythrocytes, antibodies, and nanoparticles have been used as carriers. Eleven antibody–drug conjugates (ADCs) involving covalent linkage has been commercialized as a promising cancer treatment in the last years. This review describes the general features and applications of DDS focused on the covalent conjugation system that binds the antibody carrier to the cytotoxic drug.

The Next Frontier in Pancreatic Cancer: Targeting the Tumor Immune Milieu and Molecular Pathways

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with abysmal prognosis. It is currently the third most common cause of cancer-related mortality, despite being the 11th most common cancer. Chemotherapy is standard of care in all stages of pancreatic cancer, yet survival, particularly in the advanced stages, often remains under one year. We are turning to immunotherapies and targeted therapies in PDAC in order to directly attack the core features that make PDAC notoriously resistant to chemotherapy. While the initial studies of these agents in PDAC have generally been disappointing, we find optimism in recent preclinical and early clinical research. We find that despite the immunosuppressive effects of the PDAC tumor microenvironment, new strategies, such as combining immune checkpoint inhibitors with vaccine therapy or chemokine receptor antagonists, help elicit strong immune responses. We also expand on principles of DNA homologous recombination repair and highlight opportunities to use agents, such as PARP inhibitors, that exploit deficiencies in DNA repair pathways. Lastly, we describe advances in direct targeting of driver mutations and metabolic pathways and highlight some technological achievements such as novel KRAS inhibitors.

Characterization of the impact of the MYBBP1A gene and rs3809849 on asparaginase sensitivity and cellular functions

Aims: To investigate the role of MYBBP1A gene and rs3809849 in pancreatic cancer (PANC1) and lymphoblastic leukemia (NALM6) cell lines and their response to asparaginase treatment. Materials & methods: The authors applied CRISPR-Cas9 to produce MYBBP1A knock-out (KO) and rs3809849 knock-in (KI) cell lines. The authors also interrogated rs3809849's impact on PANC1 cells through allele-specific overexpression. Results: PANC1 MYBBP1A KO cells exhibited lower proliferation capacity (p ≤ 0.05), higher asparaginase sensitivity (p = 0.01), reduced colony-forming potential (p = 0.001), cell cycle blockage in S phase, induction of apoptosis and remarkable morphology changes suggestive of an epithelial-mesenchymal transition. Overexpression of the wild-type (but not the mutant) allele of MYBBP1A-rs3809849 in PANC1 cells increased asparaginase sensitivity. NALM6 MYBBP1A KO displayed resistance to asparaginase (p < 0.0001), whereas no effect for rs3809849 KI was noted. Conclusions:MYBBP1A is important for regulating various cellular functions, and it plays, along with its rs3809849 polymorphism, a tissue-specific role in asparaginase treatment response.

Morphological Characteristics, Hemoglobin Content, and Membrane Mechanical Properties of Red Blood Cell Delivery Systems

Red blood cell (RBC)-based systems are under extensive development as platforms for the delivery of various biomedical agents. While the importance of the membrane biochemical characteristics in relation to circulation kinetics of RBC delivery systems has been recognized, the membrane mechanical properties of such carriers have not been extensively studied. Using optical methods in conjunction with image analysis and mechanical modeling, we have quantified the morphological and membrane mechanical characteristics of RBC-derived microparticles containing the near-infrared cargo indocyanine green (ICG). We find that these particles have a significantly lower surface area, volume, and deformability as compared to normal RBCs. The residual hemoglobin has a spatially distorted distribution in the particles. The membrane bending modulus of the particles is about twofold higher as compared to normal RBCs and exhibits greater resistance to flow. The induced increase in the viscous characteristics of the membrane is dominant over the elastic and entropic effects of ICG. Our results suggest that changes to the membrane mechanical properties are a result of impaired membrane-cytoskeleton attachment in these particles. We provide a mechanistic explanation to suggest that the compromised membrane-cytoskeleton attachment and altered membrane compositional and structural asymmetry induce curvature changes to the membrane, resulting in mechanical remodeling of the membrane. These findings highlight the importance of membrane mechanical properties as an important criterion in the design and engineering of future generations of RBC-based delivery systems to achieve prolonged circulation.

Recent Progress in Red Blood Cells-Derived Particles as Novel Bioinspired Drug Delivery Systems: Challenges and Strategies for Clinical Translation

Red Blood Cells (RBCs)-derived particles are an emerging group of novel drug delivery systems. The natural attributes of RBCs make them potential candidates for use as a drug carrier or nanoparticle camouflaging material as they are innately biocompatible. RBCs have been studied for multiple decades in drug delivery applications but their evolution in the clinical arena are considerably slower. They have been garnering attention for the unique capability of conserving their membrane proteins post fabrication that help them to stay non-immunogenic in the biological environment prolonging their circulation time and improving therapeutic efficiency. In this review, we discuss about the synthesis, significance, and various biomedical applications of the above-mentioned classes of engineered RBCs. This article is focused on the current state of clinical translation and the analysis of the hindrances associated with the transition from lab to clinic applications.

Targeting Nutrient Dependency in Cancer Treatment

Metabolic reprogramming is one of the hallmarks of tumor. Growing evidence suggests metabolic changes that support oncogenic progression may cause selective vulnerabilities that can be exploited for cancer treatment. Increasing demands for certain nutrients under genetic determination or environmental challenge enhance dependency of tumor cells on specific nutrient, which could be therapeutically developed through targeting such nutrient dependency. Various nutrients including several amino acids and glucose have been found to induce dependency in genetic alteration- or context-dependent manners. In this review, we discuss the extensively studied nutrient dependency and the biological mechanisms behind such vulnerabilities. Besides, existing applications and strategies to target nutrient dependency in different cancer types, accompanied with remaining challenges to further exploit these metabolic vulnerabilities to improve cancer therapies, are reviewed.

Novel Insights on the Use of L-Asparaginase as an Efficient and Safe Anti-Cancer Therapy

Simple Summary

L-asparaginase (L-ASNase) therapy is key for achieving the very high cure rate of pediatric acute lymphoblastic leukemia (ALL), yet its use is mostly confined to this indication. One main reason preventing the expansion of today’s FDA-approved L-ASNases to solid cancers is their high toxicity and side effects, which become especially challenging in adult patients. The design of optimized L-ASNase molecules provides opportunities to overcome these unwanted toxicities. An additional challenge to broader application of L-ASNases is how cells can counter the pharmacological effect of this drug and the identification of L-ASNases resistance mechanisms. In this review, we discuss recent insights into L-ASNase adverse effects, resistance mechanisms, and how novel L-ASNase variants and drug combinations can expand its clinical applicability, with a focus on both hematological and solid tumors.

Abstract

L-Asparaginase (L-ASNase) is an enzyme that hydrolyses the amino acid asparagine into aspartic acid and ammonia. Systemic administration of bacterial L-ASNase is successfully used to lower the bioavailability of this non-essential amino acid and to eradicate rapidly proliferating cancer cells with a high demand for exogenous asparagine. Currently, it is a cornerstone drug in the treatment of the most common pediatric cancer, acute lymphoblastic leukemia (ALL). Since these lymphoblasts lack the expression of asparagine synthetase (ASNS), these cells depend on the uptake of extracellular asparagine for survival. Interestingly, recent reports have illustrated that L-ASNase may also have clinical potential for the treatment of other aggressive subtypes of hematological or solid cancers. However, immunogenic and other severe adverse side effects limit optimal clinical use and often lead to treatment discontinuation. The design of optimized and novel L-ASNase formulations provides opportunities to overcome these limitations. In addition, identification of multiple L-ASNase resistance mechanisms, including ASNS promoter reactivation and desensitization, has fueled research into promising novel drug combinations to overcome chemoresistance. In this review, we discuss recent insights into L-ASNase adverse effects, resistance both in hematological and solid tumors, and how novel L-ASNase variants and drug combinations can expand its clinical applicability.

Novel systemic treatment approaches for metastatic pancreatic cancer

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) has a 5-year overall survival rate of 10 %, emphasizing the need for more effective therapies, especially in metastatic disease. The immunosuppressive tumor microenvironment, poor vascularization, and dense tumor stroma typical for PDAC are hurdles that need to be overcome by novel drugs. Investigations are moving towards more targeted treatments including immunotherapy and cell-based approaches.

AREAS COVERED

This article reviews emerging drugs in clinical development for metastatic PDAC, focusing on cellular therapies and novel treatments targeting metabolism, tumor stroma, oncogenic pathways and immunosuppression. With immunotherapy and CAR T cell therapy on the rise in hematological malignancies, the transfer to solid tumors remains intriguing. Multiple exciting clinical trials investigating innovative therapeutic strategies for PDAC are currently ongoing and reviewed herein. ClinicalTrials.gov, conference abstracts and PubMed were searched in August 2021 and assessed for information on ongoing and published clinical studies.

EXPERT OPINION

With many challenges to overcome, the optimal therapy for patients with metastatic PDAC is likely to consist of a combination of different agents. We are slowly moving from entity-dependent approaches to ones more focused on molecular and pathological features. Increasingly personalized treatment plans tailored to each patient may be the future of PDAC therapy.

L-asparaginase mediated therapy in L-asparagine auxotrophic cancers: A review

Microbial L-asparaginase is the most effective first-line therapeutic used in the treatment protocols of paediatric and adult leukemia. Leukemic cell's auxotrophy for L-asparagine is exploited as a therapeutic strategy to mediate cell death through metabolic blockade of L-asparagine using L-asparaginase. Escherichia coli and Erwinia chrysanthemi serve as the major enzyme deriving sources accepted in clinical practise and the enzyme has bestowed improvements in patient outcomes over the last 40 years. However, an array of side effects generated by the native enzymes due to glutamine co-catalysis and short serum stays augmenting frequent dosages, intended a therapeutic switch towards the development of biobetter alternatives for the enzyme including the formulations resulting in sustained local depletion of L-asparagine. In addition, the treatment with L-asparaginase in few cancer types has proven to elicit drug-induced cytoprotective autophagy mechanisms and therefore warrants concern. Although the off-target glutamine hydrolysis has been viewed in contributing the drug-induced secondary responses in cells deficient with asparagine synthetase machinery, the beneficial role of glutaminase-asparaginase in proliferative regulation of asparagine prototrophic cells has been looked forward. The current review provides an overview on the enzyme's clinical applications in leukemia and possible therapeutic implications in other solid tumours, recent advancements in drug formulations, and discusses the aspects of two-sided roles of glutaminase-asparaginases and drug-induced cytoprotective autophagy mechanisms.

Prognostic role of cell-free DNA biomarkers in pancreatic adenocarcinoma: A systematic review and meta-analysis

This systematic review and meta-analysis evaluated the prognostic role of cell-free DNA (cfDNA) in pancreatic ductal adenocarcinoma (PDAC). Eligible studies reported differences in overall (OS) and progression-free survival (PFS) by cfDNA status. The random effect model yielded the pooled hazard ratios (HRs) and 95 % confidence intervals (CI). Detection of circulant-tumor DNA (ctDNA), KRAS mutations and other cfDNA alterations constitute detectable cfDNA biomarkers. Altogether, 38 studies (3,318 patients) were eligible. Progression-free and overall survival were decreased with detectable ctDNA (HR = 1.92, 95 %CI:(1.29,2.86); HR = 2.25, 95 %CI:(1.73,2.92)) and KRAS mutations (HR = 1.88, CI:1.22,2.92,); HR = 1.52, 95 %CI:(1.22,1.90)) respectively, across various stages. In unresectable cases, ctDNA (HR = 2.50, 95 %CI:(1.94,3.23)), but not KRAS mutations (HR = 1.16, 95 %CI:(0.46,2.94)) signaled risk for progression. Detectable cfDNA biomarkers correlated with worse prognosis in resectable cases and if detected during treatment. In conclusion, cfDNA biomarkers indicate accelerated progression and decreased survival in PDAC. Significance of KRAS mutations detection in unresectable cases is to be determined.

Impact of Value Frameworks on the Magnitude of Clinical Benefit: Evaluating a Decade of Randomized Trials for Systemic Therapy in Solid Malignancies

In the era of rapid development of new, expensive cancer therapies, value frameworks have been developed to quantify clinical benefit (CB). We assessed the evolution of CB since the 2015 introduction of The American Society of Clinical Oncology and The European Society of Medical Oncology value frameworks. Randomized clinical trials (RCTs) assessing systemic therapies for solid malignancies from 2010 to 2020 were evaluated and CB (Δ) in 2010–2014 (pre-value frameworks (PRE)) were compared to 2015–2020 (POST) for overall survival (OS), progression-free survival (PFS), response rate (RR), and quality of life (QoL). In the 485 studies analyzed (12% PRE and 88% POST), the most common primary endpoint was PFS (49%), followed by OS (20%), RR (12%), and QoL (6%), with a significant increase in OS and decrease in RR as primary endpoints in the POST era (p = 0.011). Multivariable analyses revealed significant improvement in ΔOS POST (OR 2.86, 95% CI 0.46 to 5.26, p = 0.02) while controlling for other variables. After the development of value frameworks, median ΔOS improved minimally. The impact of value frameworks has yet to be fully realized in RCTs. Efforts to include endpoints shown to impact value, such as QoL, into clinical trials are warranted.

Enhanced Antitumor Effect in Liver Cancer by Amino Acid Depletion-Induced Oxidative Stress

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. HCC cells consume large amounts of glutamine to survive, but can adapt to glutamine depletion in the presence of an exogenous asparagine. L-asparaginase (ASNase) converts glutamine and asparagine to glutamate and aspartate, respectively, and has been used to treat leukemia. Here we examined the effects of ASNase treatment on HCC cells and explored the potential impact of combining ASNase with the tyrosine kinase inhibitor lenvatinib (Len) for HCC treatment. Cell viability and death of HCC cell lines treated with either Len or ASNase alone or with Len and ASNase combined were determined. We assessed mRNA and protein expression levels of glutamine synthetase (GS) and asparagine synthetase (ASNS) by real-time quantitative PCR and immunoblotting. The antitumor effect of the combination therapy relative to Len or ASNase monotherapy was also evaluated in a xenograft tumor mouse model. ASNase treatment inhibited growth of SNU387 and SNU398 HCC cells, which have low GS and high ASNS expression levels, respectively, but did not clearly inhibit growth of the other cell lines. Len plus ASNase combination therapy synergistically inhibited proliferation and induced oxidative stress leading to cell death of some HCC cells lines. However, cell death of Huh7 cells, which express ASCT2, an important glutamine transporter for cancer cells, was not affected by the combination treatment. In a xenograft model, Len combined with ASNase significantly attenuated tumor development relative to mice treated with Len or ASNase alone. ASNase-mediated targeting of two amino acids, glutamine and asparagine, which are indispensable for HCC survival, induces oxidative stress and can be a novel cancer treatment option that exerts a synergistic effect when used in combination with Len.

Encapsulation of Asparaginase as a Promising Strategy to Improve In Vivo Drug Performance

Asparaginase (ASNase) is a widely applied chemotherapeutic drug that is used to treat Acute Lymphoblastic Leukemia (ALL); however, immune responses and silent inactivation of the drug often limit its bioavailability. Many strategies have been proposed to overcome these drawbacks, including the development of improved formulations (biobetters), but only two of them are currently on the market. Nano- and micro-encapsulation are some of the most promising and novel approaches to enhance in vivo performance of ASNase, preventing the direct contact of the enzyme with the environment, protecting it from protease degradation, increasing the enzymes catalytic half-life, and in some cases, reducing immunogenicity. This review summarizes the strategies, particularly for ASNase nano- and micro-encapsulation, and their main findings, constraints, and current gaps in the state-of-the-art knowledge. The pros and cons of the use of different nanocarriers are discussed with the idea to ultimately provide safer and more effective treatments for patients with ALL.

A Targeted Catalytic Nanobody (T-CAN) with Asparaginolytic Activity

Simple Summary

The therapy of Acute Lymphoblastic Leukemia (ALL) is based on Escherichia coli (E. coli) L-asparaginase, which is a very effective drug in most cases. However, its side effects sometimes prevent its usage or impose its interruption. The main issues derive from its bacterial origin, which elicits a strong immune response in the patient, and from its generalized action on all body compartments. In this work, we describe how we generated a fully active and miniaturized form of L-asparaginase starting from a camel single domain antibody, a class of antibodies known to have a very limited immunogenicity in humans. We also targeted it onto tumor cells by attaching it to an antibody fragment directed onto the CD19 B-cell surface receptor, expressed on ALL cells. We named this new molecule “Targeted Catalytic Nanobody” (T-CAN). The T-CAN is active and successfully binds to CD19 expressing cells in vitro. Thanks to its reduced immunogenic potential, it represents a new tool which deserves further development.

Abstract

E. coli L-asparaginase is an amidohydrolase (EC 3.5.1.1) which has been successfully used for the treatment of Acute Lymphoblastic Leukemia for over 50 years. Despite its efficacy, its side effects, and especially its intrinsic immunogenicity, hamper its usage in a significant subset of cases, thus limiting therapeutic options. Innovative solutions to improve on these drawbacks have been attempted, but none of them have been truly successful so far. In this work, we fully replaced the enzyme scaffold, generating an active, miniaturized form of L-asparaginase by protein engineering of a camel single domain antibody, a class of antibodies known to have a limited immunogenicity in humans. We then targeted it onto tumor cells by an antibody scFv fragment directed onto the CD19 B-cell surface receptor expressed on ALL cells. We named this new type of nanobody-based antibody-drug conjugate “Targeted Catalytic Nanobody” (T-CAN). The new molecule retains the catalytic activity and the binding capability of the original modules and successfully targets CD19 expressing cells in vitro. Thanks to its theoretically reduced immunogenic potential compared to the original molecule, the T-CAN can represent a novel approach to tackle current limitations in L-asparaginase usage.

L-Lysine α-Oxidase: Enzyme with Anticancer Properties

L-lysine α-oxidase (LO), one of L-amino acid oxidases, deaminates L-lysine with the yield of H2O2, ammonia, and α-keto-ε-aminocaproate. Multiple in vitro and in vivo studies have reported cytotoxic, antitumor, antimetastatic, and antitumor activity of LO. Unlike asparaginase, LO has a dual mechanism of action: depletion of L-lysine and formation of H2O2, both targeting tumor growth. Prominent results were obtained on murine and human tumor models, including human colon cancer xenografts HCT 116, LS174T, and T47D with maximum T/C 12, 37, and 36%, respectively. The data obtained from human cancer xenografts in immunodeficient mice confirm the potential of LO as an agent for colon cancer treatment. In this review, we discuss recently discovered molecular mechanisms of biological action and the potential of LO as anticancer enzyme.

Clinical progress and advanced research of red blood cells based drug delivery system

Red blood cells (RBCs) are biocompatible carriers that can be employed to deliver different bioactive substances. In the past few decades, many strategies have been developed to encapsulate or attach drugs to RBCs. Osmotic-based encapsulation methods have been industrialized recently, and some encapsulated RBC formulations have reached the clinical stage for treating tumors and neurological diseases. Inspired by the intrinsic properties of intact RBCs, some advanced delivery strategies have also been proposed. These delivery systems combine RBCs with other novel systems to further exploit and expand the application of RBCs. This review summarizes the clinical progress of drugs encapsulated into intact RBCs, focusing on the loading and clinical trials. It also introduces the latest advanced research based on developing prospects and limitations of intact RBCs drug delivery system (DDS), hoping to provide a reference for related research fields and further application potential of intact RBCs based drug delivery system.

Non-pegylated Liposomal Doxorubicin as Palliative Chemotherapy in pre-Treated Advanced Pancreatic Cancer: A Retrospective Analysis of Twenty-Eight Patients

Background: Pancreatic cancer carries a devastating prognosis and is the fourth leading cause for cancer-related death in the United States and most European countries. Although one-third of patients receive a palliative third line therapy, the benefit of systemic therapy beyond second-line remains unclear. A plethora of clinical trials investigating novel drugs have failed over the past years. Due to the lack of established treatment regimens beyond second line, we offered nonpegylated liposomal doxorubicin, well known in other tumor entities, to pretreated pancreatic cancer patients requesting systemic therapy. Material and Methods: In this retrospective analysis, 28 patients with pancreatic carcinoma treated with nonpegylated liposomal doxorubicin (Myocet®) between 2012 and 2018 at our department were included. Results: For the majority of patients (n = 18, 64%), nonpeglyted liposomal doxorubicin was offered as a third-line therapy. Five patients received it as second line, four patients as fourth line, and one patient as fifth line of therapy. Half of the patients received at least a therapy cycle. The objective response rate to treatment was 7.1%. One patient had a period of radiologically confirmed stable disease with stable tumor markers. Another patient experienced partial remission. Conclusion: According to our findings the benefit of nonpegylated liposomal doxorubicin in pancreatic cancer beyond second line is limited.

Multiparametric characterization of red blood cell physiology after hypotonic dialysis based drug encapsulation process

Red blood cells (RBCs) can act as carriers for therapeutic agents and can substantially improve the safety, pharmacokinetics, and pharmacodynamics of many drugs. Maintaining RBCs integrity and lifespan is important for the efficacy of RBCs as drug carrier. We investigated the impact of drug encapsulation by hypotonic dialysis on RBCs physiology and integrity. Several parameters were compared between processed RBCs loaded with l-asparaginase (“eryaspase”), processed RBCs without drug and non-processed RBCs. Processed RBCs were less hydrated and displayed a reduction of intracellular content. We observed a change in the metabolomic but not in the proteomic profile of processed RBCs. Encapsulation process caused moderate morphological changes and was accompanied by an increase of RBCs-derived Extracellular Vesicles release. Despite a decrease in deformability, processed RBCs were not mechanically retained in a spleen-mimicking device and had increased surface-to-volume ratio and osmotic resistance. Processed RBCs half-life was not significantly affected in a mouse model and our previous phase 1 clinical study showed that encapsulation of asparaginase in RBCs prolonged its in vivo half-life compared to free forms. Our study demonstrated that encapsulation by hypotonic dialysis may affect certain characteristics of RBCs but does not significantly affect the in vivo longevity of RBCs or their drug carrier function.