Ratiometric dosing of anticancer drug combinations: controlling drug ratios after systemic administration regulates therapeutic activity in tumor-bearing mice

Remote loading in liposome: a review of current strategies and recent developments

Liposomes have gained prominence as nanocarriers in drug delivery, and the number of products in the market is increasing steadily, particularly in cancer therapeutics. Remote loading of drugs in liposomes is a significant step in the translation and commercialization of the first liposomal product. Low drug loading and drug leakage from liposomes is a translational hurdle that was effectively circumvented by the remote loading process. Remote loading or active loading could load nearly 100% of the drug, which was not possible with the passive loading procedure. A major drawback of conventional remote loading is that only a very small percentage of the drugs are amenable to this method. Therefore, methods for drug loading are still a problem for several drugs. The loading of multiple drugs in liposomes to improve the efficacy and safety of nanomedicine has gained prominence recently with the introduction of a marketed formulation (Vyxeos) that improves overall survival in acute myeloid leukemia. Different strategies for modifying the remote loading process to overcome the drawbacks of the conventional method are discussed here. The review aims to discuss the latest developments in remote loading technology and its implications in liposomal drug delivery.

Cytarabine dose intensification improves survival in older patients with secondary/high-risk acute myeloid leukemia in matched real-world versus clinical trial data

Since 1980's, the established/standard treatment of acute myeloid leukemia (AML) is cytarabine infusion with anthracycline (7 + 3 regimen). We compared the 7 + 3 regimen in older secondary/high-risk AML patients from a clinical trial with a matched population from the Swedish AML Registry treated with an increased cytarabine dose in induction and consolidation as recommended in the Swedish National Guidelines since 2005. After successful propensity score matching, 104 patients per group were included. The primary outcome was overall survival (OS), and standard dosed patients had a median OS of 6.4 versus 10.7 months with increased dose intensity (hazard ratio: 0.69, p = 0.012), with 5-year OS of 8.7% and 18.1%, and remission rates of 36% and 60%, respectively (p < 0.001). Median OS after allogeneic hematopoietic cell transplantation (in 27.9% per group) was 10.4 and 20.7 months, respectively. We conclude that the more intensive cytarabine schedule seems to provide improved outcomes inthe investigated AML patient group.

Updates in biology, classification, and management of acute myeloid leukemia with antecedent hematologic disorder and therapy related acute myeloid leukemia

Acute myeloid leukemia with antecedent hematologic disorder (AHD-AML) and therapy related AML (t-AML) constitute a heterogenous disease with inferior outcomes. It is often characterized by high-risk cytogenetic and molecular alterations associated with AHD or prior cancer therapy. Historically, the standard of care treatment has been intensive induction with "7 + 3", with an improved overall response rate and survival with CPX-351. Results from large registry-based studies suggested that allogeneic hematopoietic stem cell transplant is preferable to consolidation chemotherapy alone for achieving long-term survival in patients with AHD-AML. Prevalence of high-risk genetic features and advanced age and comorbidities in patients make AHD-AML and t-AML clinically challenging subgroups to treat with intensive approaches. Recent reports on less intensive treatment options, particularly the hypomethylating agent-venetoclax combination, have shown encouraging response rates in these patients. However, emerging resistance mechanisms compromise duration of response and overall survival. Several novel agents targeting apoptotic machinery, signaling pathways, and immune checkpoints are under clinical investigation, with an aim to truly improve overall outcomes in this subgroup. We reviewed updates in biology, classification, and clinical data comparing safety and efficacy of intensive and less intensive treatment options, and summarized ongoing studies with promising novel therapies in AHD-AML and t-AML.

Synchronized Codelivery of Combination Chemotherapies Intratumorally Using a Lipidic Lyotropic Liquid Crystal System

In this work, an injectable in situ depot-forming lipidic lyotropic liquid crystal (L3C) system is developed to codeliver a precisely synchronized combination of chemotherapeutics intratumorally. The developed L3C system is composed of amphiphilic lipids and surfactants, including monoolein, phosphatidylcholine, tocopherol acetate, and d-α-tocopherol polyethylene glycol 1000 succinate. Owing to its amphiphilic nature, the developed formulation can coaccommodate both hydrophobic and hydrophilic chemotherapeutic moieties simultaneously. The study presents a proof of concept by designing a combination chemotherapy regimen in vitro and demonstrating its in vivo translation using doxorubicin and paclitaxel as model hydrophilic and hydrophobic drug moieties, respectively. The synchronized combination of the two chemotherapeutics with maximum synergistic activity was identified, coloaded in the developed L3C system at predefined stoichiometric ratios, and evaluated for antitumor efficacy in the 4T1 breast tumor model in BALB/c mice. The drug-loaded L3C formulation is a low-viscosity injectable fluid with a lamellar phase that transforms into a hexagonal mesophase depot system upon intratumoral injection. The drug-loaded depot system locally provides sustained intratumoral delivery of the chemotherapeutics combination at their precisely synchronized ratio for over a period of one month. Results demonstrate that the exposure of the tumor to the precisely synchronized intratumoral chemotherapeutics combination via the developed L3C system resulted in significantly higher antitumor activity and reduced cardiotoxicity compared to the unsynchronized combination chemotherapy or the synchronized but uncoordinated drug delivery administered by a conventional intravenous route. These findings demonstrate the potential of the developed L3C system for achieving synchronized codelivery of the chemotherapeutics combination intratumorally and improving the efficacy of combination chemotherapy.

Nanomedicine Tumor Targeting

Nanomedicines are extensively explored for cancer therapy. By delivering drug molecules more efficiently to pathological sites and by attenuating their accumulation in healthy organs and tissues, nanomedicine formulations aim to improve the balance between drug efficacy and toxicity. More than 20 cancer nanomedicines are approved for clinical use, and hundreds of formulations are in (pre)clinical development. Over the years, several key pitfalls have been identified as bottlenecks in nanomedicine tumor targeting and translation. These go beyond materials- and production-related issues, and particularly also encompass biological barriers and pathophysiological heterogeneity. In this manuscript, the author describes the most important principles, progress, and products in nanomedicine tumor targeting, delineates key current problems and challenges, and discusses the most promising future prospects to create clinical impact.

Nanomedicine as a multimodal therapeutic paradigm against cancer: on the way forward in advancing precision therapy

Recent years have witnessed dramatic improvements in nanotechnology-based cancer therapeutics, and it continues to evolve from the use of conventional therapies (chemotherapy, surgery, and radiotherapy) to increasingly multi-complex approaches incorporating thermal energy-based tumor ablation (e.g. magnetic hyperthermia and photothermal therapy), dynamic therapy (e.g. photodynamic therapy), gene therapy, sonodynamic therapy (e.g. ultrasound), immunotherapy, and more recently real-time treatment efficacy monitoring (e.g. theranostic MRI-sensitive nanoparticles). Unlike monotherapy, these multimodal therapies (bimodal, i.e., a combination of two therapies, and trimodal, i.e., a combination of more than two therapies) incorporating nanoplatforms have tremendous potential to improve the tumor tissue penetration and retention of therapeutic agents through selective active/passive targeting effects. These combinatorial therapies can correspondingly alleviate drug response against hypoxic/acidic and immunosuppressive tumor microenvironments and promote/induce tumor cell death through various multi-mechanisms such as apoptosis, autophagy, and reactive oxygen-based cytotoxicity, e.g., ferroptosis, etc. These multi-faced approaches such as targeting the tumor vasculature, neoangiogenic vessels, drug-resistant cancer stem cells (CSCs), preventing intra/extravasation to reduce metastatic growth, and modulation of antitumor immune responses work complementary to each other, enhancing treatment efficacy. In this review, we discuss recent advances in different nanotechnology-mediated synergistic/additive combination therapies, emphasizing their underlying mechanisms for improving cancer prognosis and survival outcomes. Additionally, significant challenges such as CSCs, hypoxia, immunosuppression, and distant/local metastasis associated with therapy resistance and tumor recurrences are reviewed. Furthermore, to improve the clinical precision of these multimodal nanoplatforms in cancer treatment, their successful bench-to-clinic translation with controlled and localized drug-release kinetics, maximizing the therapeutic window while addressing safety and regulatory concerns are discussed. As we advance further, exploiting these strategies in clinically more relevant models such as patient-derived xenografts and 3D organoids will pave the way for the application of precision therapy.

Rationale and design of the Children's Oncology Group study AAML1831 integrated cardiac substudies in pediatric acute myeloid leukemia therapy

Background

Pediatric acute myeloid leukemia (AML) therapy is associated with substantial short- and long-term treatment-related cardiotoxicity mainly due to high-dose anthracycline exposure. Early left ventricular systolic dysfunction (LVSD) compromises anthracycline delivery and is associated with inferior event-free and overall survival in de novo pediatric AML. Thus, effective cardioprotective strategies and cardiotoxicity risk predictors are critical to optimize cancer therapy delivery and enable early interventions to prevent progressive LVSD. While dexrazoxane-based cardioprotection reduces short-term cardiotoxicity without compromising cancer survival, liposomal anthracycline formulations have the potential to mitigate cardiotoxicity while improving antitumor efficacy. This overview summarizes the rationale and methodology of cardiac substudies within AAML1831, a randomized Children's Oncology Group Phase 3 study of CPX-351, a liposomal formulation of daunorubicin and cytarabine, in comparison with standard daunorubicin/cytarabine with dexrazoxane in the treatment of de novo pediatric AML.

Methods/design

Children (age <22 years) with newly diagnosed AML were enrolled and randomized to CPX-351-containing induction 1 and 2 (Arm A) or standard daunorubicin and dexrazoxane-containing induction (Arm B). Embedded cardiac correlative studies aim to compare the efficacy of this liposomal anthracycline formulation to dexrazoxane for primary prevention of cardiotoxicity by detailed core lab analysis of standardized echocardiograms and serial cardiac biomarkers throughout AML therapy and in follow-up. In addition, AAML1831 will assess the ability of early changes in sensitive echo indices (e.g., global longitudinal strain) and cardiac biomarkers (e.g., troponin and natriuretic peptides) to predict subsequent LVSD. Finally, AAML1831 establishes expert consensus-based strategies in cardiac monitoring and anthracycline dose modification to balance the potentially competing priorities of cardiotoxicity reduction with optimal leukemia therapy.

Discussion

This study will inform diagnostic, prognostic, preventative, and treatment strategies regarding cardiotoxicity during pediatric AML therapy. Together, these measures have the potential to improve leukemia-free and overall survival and long-term cardiovascular health in children with AML. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT04293562.

Lipid-based nanoparticle-mediated combination therapy for breast cancer management: a comprehensive review

Breast cancer due to the unpredictable and complex etiopathology combined with the non-availability of any effective drug treatment has become the major root of concern for oncologists globally. The number of women affected by the said disease state is increasing at an alarming rate attributed to environmental and lifestyle changes indicating at the exploration of a novel treatment strategy that can eradicate this aggressive disease. So far, it is treated by promising nanomedicine monotherapy; however, according to the numerous studies conducted, the inadequacy of these nano monotherapies in terms of elevated toxicity and resistance has been reported. This review, therefore, puts forth a new multimodal strategic approach to lipid-based nanoparticle-mediated combination drug delivery in breast cancer, emphasizing the recent advancements. A basic overview about the combination therapy and its index is firstly given. Then, the various nano-based combinations of chemotherapeutics involving the combination delivery of synthetic and herbal agents are discussed along with their examples. Further, the recent exploration of chemotherapeutics co-delivery with small interfering RNA (siRNA) agents has also been explained herein. Finally, a section providing a brief description of the delivery of chemotherapeutic agents with monoclonal antibodies (mAbs) has been presented. From this review, we aim to provide the researchers with deep insight into the novel and much more effective combinational lipid-based nanoparticle-mediated nanomedicines tailored specifically for breast cancer treatment resulting in synergism, enhanced antitumor efficacy, and low toxic effects, subsequently overcoming the hurdles associated with conventional chemotherapy.

Pediatric acute myeloid leukemia: Insight into genetic landscape and novel targeted approaches

Acute myeloid leukemia (AML) is a very heterogeneous hematological malignancy that accounts for approximately 20% of all pediatric leukemia cases. The outcome of pediatric AML has improved over the last decades, with overall survival rates reaching up to 70%. Still, AML is among the leading types of pediatric cancers by its high mortality rate. Modulation of standard therapy, like chemotherapy intensification, hematopoietic stem cell transplantation and optimized supportive care, could only get this far, but for the significant improvement of the outcome in pediatric AML, development of novel targeted therapy approaches is necessary. In recent years the advances in genomic techniques have greatly expanded our knowledge of the AML biology, revealing molecular landscape and complexity of the disease, which in turn have led to the identification of novel therapeutic targets. This review provides a brief overview of the genetic landscape of pediatric AML, and how it's used for precise molecular characterization and risk stratification of the patients, and also for the development of effective targeted therapy. Furthermore, this review presents recent advances in molecular targeted therapy and immunotherapy with an emphasis on the therapeutic approaches with significant clinical benefits for pediatric AML.

Development of constitutively synergistic nanoformulations to enhance chemosensitivity in T-cell leukemia

Advances in multiagent chemotherapy have led to recent improvements in survival for patients with acute lymphoblastic leukemia (ALL); however, a significant fraction do not respond to frontline chemotherapy or later relapse with recurrent disease, after which long-term survival rates remain low. To develop new, effective treatment options for these patients, we conducted a series of high-throughput combination drug screens to identify chemotherapies that synergize in a lineage-specific manner with MRX-2843, a small molecule dual MERTK and FLT3 kinase inhibitor currently in clinical testing for treatment of relapsed/refractory leukemias and solid tumors. Using experimental and computational approaches, we found that MRX-2843 synergized strongly-and in a ratio-dependent manner-with vincristine to inhibit both B-ALL and T-ALL cell line expansion. Based on these findings, we developed multiagent lipid nanoparticle formulations of these drugs that not only delivered defined drug ratios intracellularly in T-ALL, but also improved anti-leukemia activity following drug encapsulation. Synergistic and additive interactions were recapitulated in primary T-ALL patient samples treated with MRX-2843 and vincristine nanoparticle formulations, suggesting their clinical relevance. Moreover, the nanoparticle formulations reduced disease burden and prolonged survival in an orthotopic murine xenograft model of early thymic precursor T-ALL (ETP-ALL), with both agents contributing to therapeutic activity in a dose-dependent manner. In contrast, nanoparticles containing MRX-2843 alone were ineffective in this model. Thus, MRX-2843 increased the sensitivity of ETP-ALL cells to vincristine in vivo. In this context, the additive particles, containing a higher dose of MRX-2843, provided more effective disease control than the synergistic particles. In contrast, particles containing an even higher, antagonistic ratio of MRX-2843 and vincristine were less effective. Thus, both the drug dose and the ratio-dependent interaction between MRX-2843 and vincristine significantly impacted therapeutic activity in vivo. Together, these findings present a systematic approach to high-throughput combination drug screening and multiagent drug delivery that maximizes the therapeutic potential of combined MRX-2843 and vincristine in T-ALL and describe a novel translational agent that could be used to enhance therapeutic responses to vincristine in patients with T-ALL. This broadly generalizable approach could also be applied to develop other constitutively synergistic combination products for the treatment of cancer and other diseases.

Nanoparticle-Based Combination Therapy Enhances Fulvestrant Efficacy and Overcomes Tumor Resistance in ER-Positive Breast Cancer

Nanoparticles (NP) spanning diverse materials and properties have the potential to encapsulate and to protect a wide range of therapeutic cargos to increase bioavailability, to prevent undesired degradation, and to mitigate toxicity. Fulvestrant, a selective estrogen receptor degrader, is commonly used for treating patients with estrogen receptor (ER)-positive breast cancer, but its broad and continual application is limited by poor solubility, invasive muscle administration, and drug resistance. Here, we developed an active targeting motif-modified, intravenously injectable, hydrophilic NP that encapsulates fulvestrant to facilitate its delivery via the bloodstream to tumors, improving bioavailability and systemic tolerability. In addition, the NP was coloaded with abemaciclib, an inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), to prevent the development of drug resistance associated with long-term fulvestrant treatment. Targeting peptide modifications on the NP surface assisted in the site-specific release of the drugs to ensure specific toxicity in the tumor tissues and to spare normal tissue. The NP formulation (PPFA-cRGD) exhibited efficient tumor cell killing in both in vitro organoid models and in vivo orthotopic ER-positive breast cancer models without apparent adverse effects, as verified in mouse and Bama miniature pig models. This NP-based therapeutic provides an opportunity for continual and extensive clinical application of fulvestrant, thus indicating its promise as a treatment option for patients with ER-positive breast cancer.

SIGNIFICANCE

A smart nanomedicine encapsulating fulvestrant to improve its half-life, bioavailability, and tumor-targeting and coloaded with CDK4/6 inhibitor abemaciclib to block resistance is a safe and effective therapy for ER-positive breast cancer.

Induced Vascular Normalization-Can One Force Tumors to Surrender to a Better Microenvironment?

Immunotherapy has changed the way many cancers are being treated. Researchers in the field of immunotherapy and tumor immunology are investigating similar questions: How can the positive benefits achieved with immunotherapies be enhanced? Can this be achieved through combinations with other agents and if so, which ones? In our view, there is an urgent need to improve immunotherapy to make further gains in the overall survival for those patients that should benefit from immunotherapy. While numerous different approaches are being considered, our team believes that drug delivery methods along with appropriately selected small-molecule drugs and drug candidates could help reach the goal of doubling the overall survival rate that is seen in some patients that are given immunotherapeutics. This review article is prepared to address how immunotherapies should be combined with a second treatment using an approach that could realize therapeutic gains 10 years from now. For context, an overview of immunotherapy and cancer angiogenesis is provided. The major targets in angiogenesis that have modulatory effects on the tumor microenvironment and immune cells are highlighted. A combination approach that, for us, has the greatest potential for success involves treatments that will normalize the tumor's blood vessel structure and alter the immune microenvironment to support the action of immunotherapeutics. So, this is reviewed as well. Our focus is to provide an insight into some strategies that will engender vascular normalization that may be better than previously described approaches. The potential for drug delivery systems to promote tumor blood vessel normalization is considered.

A comparative safety review of targeted therapies for acute myeloid leukemia

INTRODUCTION

Acute myeloid leukemia (AML) treatment has primarily focused on 7 + 3 chemotherapy, but in the last decade there has been a significant increase in new therapies, mostly targeted agents, approved for the treatment of AML. We performed a comparative analysis of the unique safety profile of each of these new agents.

AREAS COVERED

We conducted a review of the current literature on public databases (PubMed, ClinicalTrials.gov, and U.S. Food and Drug Administration) regarding new AML drugs that were approved from 2017 to 2023.

EXPERT OPINION

The diagnosis of AML typically carries a poor prognosis but with an increase in the number of drugs that are now available, patients' outcomes are improving. With novel mechanisms of action, the use of these agents introduces different safety profiles, occasionally with adverse events not previously seen with standard chemotherapy or at different frequencies. An understanding of the drugs available and the safety concerns associated with each one is crucial to selecting the best available option for each patient, and early recognition and appropriate management of drug-related adverse effects.

Curcumin combining temozolomide formed localized nanogel for inhibition of postsurgical chemoresistant glioblastoma

Aim: To investigate the use of nanoparticle (NP)-encapsulated injectable thermosensitive hydrogel-formed nanogel for inhibition of postsurgical residual temozolomide (TMZ)-resistant glioblastoma (GBM) recurrence. Materials & methods: Curcumin (Cur) was coloaded with TMZ into PEG-PLGA NPs, then NPs were further encapsulated into a thermosensitive hydrogel to form a nanogel, which was injected into the resection cavity of the GBM postsurgery. Results: The prepared nanogel displayed excellent drug-loading capacity and long-term drug release. Estimated survival characteristics demonstrated that the nanogel could play a significant role in TMZ-resistant tumor inhibition with low drug-induced toxicity. The originally designed ratio of Cur/TMZ was sustained, making it an effective therapeutic outcome. Conclusion: Cur-combined TMZ-formed nanogels can be a promising candidate for the local inhibition of GBM recurrence.

Ratio-dependent effects of photoactivated hypericin and manumycin A on their genotoxic and mutagenic potential

Natural compounds originated from plants and microorganisms and their combinations are currently being investigated as a possible treatment for several diseases including cancer. Hypericin (photodynamically-active pigment from Hypericum perforatum L.) and manumycin A (inhibitor of farnesyltransferase from Streptomyces parvulus) belong to the chemicals potentially applicable in clinical practice. In this study we evaluated potential cytotoxic (via trypan blue exclusion test), genotoxic (via DNA-topology and comet assays), and mutagenic effects (via bacterial reverse mutation test) of these compounds and their combinations considering the molecular mechanism of their action in cell-free and cellular systems. Our results did not reveal neither cytotoxic nor mutagenic activities of tested compounds and their combinations. Regarding the genotoxic potential, no damage of plasmid DNA in cell-free system was detected. On the other hand, photoactivated hypericin and manumycin A were able to induce primary DNA damage in human lymphocytes analyzed by comet assay. The possible antagonistic interactions between these two metabolites were estimated using SynergyFinder software analysis and experimental data obtained from comet assay. Our findings indicate that not only the presence of substances, but also their ratio plays an important role in resulting effects of the combined treatment in cellular system.

Recent advances in targeted therapies in acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. While survival for younger patients over the last several decades has improved nearly sixfold with the optimization of intensive induction chemotherapy and allogeneic stem cell transplantation (alloHSCT), this effect has been largely mitigated in older and less fit patients as well as those with adverse-risk disease characteristics. However, the last 10 years has been marked by major advances in the molecular profiling of AML characterized by a deeper understanding of disease pathobiology and therapeutic vulnerabilities. In this regard, the classification of AML subtypes has recently evolved from a morphologic to a molecular and genetic basis, reflected by recent updates from the World Health Organization and the new International Consensus Classification system. After years of stagnation in new drug approvals for AML, there has been a rapid expansion of the armamentarium against this disease since 2017. Low-intensity induction therapy with hypomethylating agents and venetoclax has substantially improved outcomes, including in those previously considered to have a poor prognosis. Furthermore, targeted oral therapies against driver mutations in AML have been added to the repertoire. But with an accelerated increase in treatment options, several questions arise such as how to best sequence therapy, how to combine therapies, and if there is a role for maintenance therapy in those who achieve remission and cannot undergo alloHSCT. Moreover, certain subtypes of AML, such as those with TP53 mutations, still have dismal outcomes despite these recent advances, underscoring an ongoing unmet need and opportunity for translational advances. In this review, we will discuss recent updates in the classification and risk stratification of AML, explore the literature regarding low-intensity and novel oral combination therapies, and briefly highlight investigative agents currently in early clinical development for high-risk disease subtypes.

Self-Assembly of a Linear-Dendritic Polymer Containing Cisplatin and Norcantharidin into Raspberry-like Multimicelle Clusters for the Efficient Chemotherapy of Liver Cancer

Combination chemotherapy has been proved to be an effective strategy in the clinic, and nanoformulations have drawn much attention in the field of drug delivery. However, conventional nanocarriers suffer from shortcomings such as inefficient coloading and undesired molar ratios of the combined drugs, preleakage of cargos during systemic circulation, and lack of cancer-selective drug release. To achieve tumor-specific codelivery of cisplatin (CDDP) and norcantharidin (NCTD) for synergistic treatment of liver cancer, a novel linear-dendritic polymer, termed as G1(PPDC)x, was designed and synthesized, where a prodrug consisting of cisplatin (CDDP) and norcantharidin (NCTD) was conjugated to PEG2000 via ester bonds to fabricate linear polymer-drug conjugates, and the conjugates were subsequently grafted to the terminal hydroxyls of a dendritic polycarbonate core. Benefiting from the hydrogen bond interactions, G1(PPDC)x could spontaneously self-assemble into a unique type of raspberry-like multimicelle clusters in solution (G1(PPDC)x-PMs). G1(PPDC)x-PMs possessed an optimal synergistic ratio of CDDP and NCTD, without obvious premature release or disassembly in biological environments. Intriguingly, upon extravasation into the interstitial tumor tissues, G1(PPDC)x-PMs (132 nm in diameter) could disassemble and reassemble into smaller micelles (40 nm in diameter) in response to the mildly acidic tumor microenvironment, which would enhance the deep tumor penetration and cellular accumulation of drugs. In vivo delivery of G1(PPDC)x-PMs led to a significantly prolonged blood circulation half-life, which is beneficial to achieve sufficient tumor accumulation through the enhanced permeability and retention (EPR) effect. G1(PPDC)x-PMs displayed the best antitumor activity in H22 tumor-bearing mice with a tumor inhibition rate of 78.87%. Meanwhile, G1(PPDC)x-PMs alleviated both myelosuppression toxicities of CDDP and vascular irritation of NCTD. Our results demonstrated that G1(PPDC)x-PMs could serve as an effective drug delivery system for codelivery of CDDP and NCTD to treat liver cancer efficiently.

CPX-351 Yields Similar Response and Survival Outcome in Younger and Older Patients With Secondary Acute Myeloid Leukemia

BACKGROUND

CPX-351 was approved by the FDA in 2017 as frontline induction chemotherapy for patients aged ≥18 years with newly diagnosed acute myeloid leukemia (AML) which includes myelodysplasia-related changes (AML-MRC) and therapy-related acute myeloid leukemia (t-AML). The efficacy of CPX-351 among younger patients (aged <60 years) is currently unclear, as the large, randomized phase 3 study that led to approval of CPX-351 only included patients between the ages of 60 and 75 years.

METHODS

We performed a retrospective study of clinical and molecular data from adult patients with newly diagnosed AML-MRC or t-AML treated with CPX-351. Patients were divided into 2 cohorts: aged <60 years (cohort A) and aged ≥60 years (cohort B). We compared overall response rate (ORR) and median overall survival (mOS) between the cohorts.

RESULTS

Of 169 evaluable patients, 21.3% were in cohort A and 78.7% were in cohort B. ORR of the entire cohort was 53.3%; ORR of cohort A was 47.2% compared with 54.9% for cohort B (P = .46). Overall, 54.4% of responding patients proceeded to allogenic stem cell transplant (allo-SCT), including 52.9% of patients in cohort A and 54.8% in cohort B (P = 1.00). At a median follow-up of 24 months, mOS of the entire cohort was 16 months and was similar between cohorts A and B (18 vs. 15 months, respectively; P = .29).

CONCLUSION

CPX-351 resulted in similar response rates and survival outcomes among both younger and older adult patients with newly diagnosed AML-MRC or t-AML.

Current Status of CPX-351 Therapy in Acute Myeloid Leukemia and Myelodysplastic Syndrome

Acute myeloid leukemia (AML) treatment landscape had evolved over the last decades with better understanding of the disease genomics and the use of the targeted therapy, despite this treatment evolution, 7 + 3 remains the mainstay treatment for most AML cases. Many attempts had been made to improve the treatment outcome with 7 + 3 like manipulating the doses or the duration, but with no significant change in the outcome. In 2017 FDA approved CPX-351,a liposomal formulation of cytarabine and daunorubicin at a fixed 5:1 molar ratio, for the treatment of adults with newly diagnosed AML with myelodysplasia-related changes and therapy-related AML (t-AML). Since the approval, many trials were conducted or still ongoing in assessing the role of CPX-351 in treating different patient populations, AML subcategories or when combined with different agents. In this review, we will summarize the current role of CPX-351 in treating this largely heterogeneous disease.

Codelivery of Gemcitabine and MUC1 Inhibitor Using PEG-PCL Nanoparticles for Breast Cancer Therapy

In breast cancer therapy, Gemcitabine (Gem) is an antineoplastic antimetabolite with greater anticancer efficacy and tolerability. However, effectiveness of Gem is limited by its off-target effects. The synergistic potential of MUC1 (mucin 1) inhibitors and Gem-loaded polymeric nanoparticles (NPs) was discussed in this work in order to reduce dose-related toxicities and enhance the therapeutic efficacy. The double emulsion solvent evaporation method was used to prepare poly(ethylene glycol) methyl ether-block-poly-caprolactone (PEG-PCL)-loaded Gem and MUC 1 inhibitor NPs. The average size of Gem and MUC 1 inhibitor-loaded NPs was 128 nm, with a spherical shape. Twin-loaded NPs containing Gem and the MUC1 inhibitor decreased IC₅₀ and behaved synergistically. Furthermore, in vitro mechanistic studies, that is, loss of MMP, clonogenic assay, Annexin V FITC assay, and Western blotting to confirm apoptosis with simultaneous induction of autophagy using acridine orange (AO) staining were performed in this study. Furthermore, the investigated NPs upon combination exhibited greater loss of MMP and decreased clonogenic potential with simultaneous induction of autophagy in MCF-7 cells. Annexin V FITC clearly showed the percentage of apoptosis while Western blotting protein expression analysis revealed an increase in caspase-3 activity with simultaneous decrease in Bcl-2 protein expression, a hallmark of apoptosis. The effectiveness of the Ehrlich ascites solid (EAT) mice treated with Gem-MUC1 inhibitor NPs was higher than that of the animals treated alone. Overall, the combined administration of Gem and MUC1 inhibitor-loaded NPs was found to be more efficacious than Gem and MUC1 inhibitor delivered separately.

The effects of intermolecular interactions on the stability and in vitro drug release of daunorubicin/cytarabine co-loaded liposome

Various studies were performed on the intermolecular interactions of daunorubicin (DNR) and cytarabine (Ara-C) co-loaded liposome to predict and elucidate its stability and in vitro drug release behavior. Langmuir monolayer and spectroscopy studies showed interactions between its components. The Langmuir monolayer study and blank liposomes stability study illustrated that interactions between lipids could affect their stability, and the DSPC/DSPG/Chol (7/2/1, mol%) mixed system tended to be thermodynamically and physicochemically stable. The interactions between daunorubicin and copper ions were then investigated by ultraviolet-visible (UV-vis) electronic absorption spectroscopy and circular dichroism (CD) spectroscopy, which revealed that the DNR-Cu complex was composed of daunorubicin and copper ions at a molar ratio of 1:1 or 1:2, and its solubility was related to the acidity of the solution. In vitro release experiment of liposomes with different copper gluconate contents illustrated that the interactions between drugs and copper ions were conducive to the retention and synergetic release of drugs. The stability and release studies of the DSPC/DSPG/Chol (7/2/1, mol%) co-loaded liposome illustrated that it had good storage and plasma stability, and the release behaviors of drugs were pH-related, i.e., drugs could be released faster under acidic condition. These studies indicated that intermolecular interactions could affect the stability and release behavior of the liposome, and a certain ratio of components could be conducive to its stability and synergistic release of drugs.

Co-encapsulation of flavonoids with anti-cancer drugs: a challenge ahead

Flavonoids have been considered as promising molecules for cancer treatment due to their pleiotropic properties such as anti-carcinogenic, anti-angiogenic or efflux proteins inhibition. However, due to their lipophilic properties and their chemical instability, vectorization seems compulsory to administer flavonoids. Flavonoids have been co-encapsulated with other anti-cancer agents in a broad range of nanocarriers aiming to i) achieve a synergistic/additive effect at the tumor site, ii) delay drug resistance apparition by combining agents with different action mechanisms or iii) administer a lower dose of the anti-cancer drug, reducing its toxicity. However, co-encapsulation could lead to a change in the nanoparticles' diameter and drug-loading, as well as a decrease in their stability during storage. The preparation process should also take into accounts the physico-chemical properties of both the flavonoid and the anti-cancer agent. Moreover, the co-encapsulation could affect the release and activity of each drug. This review aims to study the formulation, preparation and characterization strategies of these co-loaded nanomedicines, as well as their stability. The in vitro assays to predict the nanomedicines' behavior in biological fluids, as well as their in vivo efficacy, are also discussed. A special focus concerns the evaluation of their synergistic effect on tumor treatment.

In Situ Micro-Nano Conversion Augmented Tumor-Localized Immunochemotherapy

The immune checkpoint blockade (ICB) therapy based on monoclonal antibodies still suffers from a lower immune response rate and severe immune-related side effects, which greatly compromise its therapeutic benefits. Herein, ultrasound (US) microbubbles (MBs) that locally delivered the camptothecin-floxuridine (CF) drug combination and anti-PD-L1 blocking antibody (αPD-L1) to tumors were developed to improve ICB therapy. The resulting αPCF MBs exhibited good stability, allowing their use as US imaging contrast agents to trace the drug delivery in vivo. Furthermore, the combination of αPCF MBs treatment and disrupted US irradiation triggered tumor in situ conversion of αPCF MBs to αPCF NPs while promoting higher tumor cell uptake and deeper tumor penetration as confirmed by the US/fluorescence bimodal imaging. Camptothecin (CPT) and floxuridine (FUDR) were further released at a fixed 1:1 molar ratio within the tumor microenvironment (TME) to synergistically elicit an immunogenic tumor phenotype and sensitize tumors to αPD-L1-mediated ICB therapy, while the local simultaneous delivery of immunotherapeutic αPD-L1 further reversed the immunosuppressive tumor microenvironment and promoted the infiltration of cytotoxic T lymphocytes (CTLs), thus achieving a synergistic therapeutic effect of chemotherapy and immunotherapy in the CT26 tumor-bearing mice. Thus, αPCF MBs + US mediated local co-delivering of the drug combination and αPD-L1 well augmented the ICB therapy while effectively minimizing the off-target side effects, providing a safe and universal therapeutic strategy for tumor immunotherapy.

Multifunctional Lipid Bilayer Nanocarriers for Cancer Immunotherapy in Heterogeneous Tumor Microenvironments, Combining Immunogenic Cell Death Stimuli with Immune Modulatory Drugs

In addition to the contribution of cancer cells, the solid tumor microenvironment (TME) has a critical role in determining tumor expansion, antitumor immunity, and the response to immunotherapy. Understanding the details of the complex interplay between cancer cells and components of the TME provides an unprecedented opportunity to explore combination therapy for intervening in the immune landscape to improve immunotherapy outcome. One approach is the introduction of multifunctional nanocarriers, capable of delivering drug combinations that provide immunogenic stimuli for improvement of tumor antigen presentation, contemporaneous with the delivery of coformulated drug or synthetic molecules that provide immune danger signals or interfere in immune-escape, immune-suppressive, and T-cell exclusion pathways. This forward-looking review will discuss the use of lipid-bilayer-encapsulated liposomes and mesoporous silica nanoparticles for combination immunotherapy of the heterogeneous immune landscapes in pancreatic ductal adenocarcinoma and triple-negative breast cancer. We describe how the combination of remote drug loading and lipid bilayer encapsulation is used for the synthesis of synergistic drug combinations that induce immunogenic cell death, interfere in the PD-1/PD-L1 axis, inhibit the indoleamine-pyrrole 2,3-dioxygenase (IDO-1) immune metabolic pathway, restore spatial access to activated T-cells to the cancer site, or reduce the impact of immunosuppressive stromal components. We show how an integration of current knowledge and future discovery can be used for a rational approach to nanoenabled cancer immunotherapy.

Dual Vinorelbine bitartrate and Resveratrol Loaded Polymeric Aqueous core Nanocapsules for Synergistic Efficacy in Breast Cancer

AIM

The current study focused on the development and evaluation of aqueous core nanocapsules (ACNs) as an effective carrier to deliver an optimal synergistic combination of a highly water soluble Vinorelbine bitartrate (VRL) and a poorly water-soluble Resveratrol (RES) for treatment of breast cancer.

METHODS

Various molar ratios of VRL to RES were screened against MCF-7 cell lines to determine the synergistic effects using Chou-Talalay method. Synergistic ratio of therapeutic agents was then incorporated into aqueous core nanocapsules utilizing a double emulsion solvent evaporation technique to yield dual drug loaded nanocapsules (dd-ACNs). The dd-ACNs were optimized using Box-Behnken design and characterized for physicochemical parameters such as particle size, zeta potential, polydispersity index, total drug content and encapsulation efficiency, surface morphology, drug excipient compatibility by FTIR and DSC, release kinetics, toxicity studies and anticancer efficacy (in-vitro and in-vivo).

RESULTS

Results demonstrated that the combination exhibited maximum synergy when higher doses of VRL were combined with smaller doses of RES (1:1, 5:1, and 10:1). The dual drug loaded ACNs were found to be stable and depicted a core-shell structure, narrow size range (150.2 ± 3.2 nm) with enhanced encapsulation (80% for VRL and 99% for RES). Moreover, the dd-ACNs were 5 times more efficacious in-vitro than a combination of free drugs, while reducing systemic toxicity. Also, pre-clinical evaluation of dd-ACNs also depicted drastic reduction of tumor volume as compared tp pristine VRL and physical combination of drugs.

CONCLUSION

The developed dd-ACNs can be applied as potential carrier for delivery of combination of chemotherapeutics at a synergistic ratio at tumor site.

Co-Delivery of Precisely Prescribed Multi-Prodrug Combination by an Engineered Nanocarrier enables Efficient Individualized Cancer Chemotherapy

The limited anticancer drug library and the frequent occurrence of drug resistance have driven monotherapy-based cancer therapy into a difficult situation. Considering the formidable process of new drug discovery, combination therapy using currently available drugs is a potential alternative. Nevertheless, the barrier between in vitro combination screening and precise in vivo delivery remains insurmountable in the current free-drug- or nanoparticle (NP)-based combination therapy, which substantially hinders the application of combination therapy. Herein, a novel, precise drug delivery strategy to realize efficient and individualized combination therapy is proposed. Nanomedicine (NM) is engineered using a microfluidics-based mixer by combining rationally designed polymeric prodrugs of three commercial chemotherapeutics and a cascade-responsive block copolymer; the NM possesses ratiometric drug loading and synchronized drug release. In addition to quantitative drug loading and precisely controlled drug combination, consistent nanoproperties of these NPs make their in vivo fate predictable. Consequently, tumor growth and metastasis can be effectively inhibited by precisely prescribed NPs derived from in vitro combination screening. This proof-of-concept study clearly reveals the feasibility of overcoming the current drug-library limitations through precise delivery of any predetermined drug combination, facilitating translational research of individualized combination therapy.

Targeted liposomal doxorubicin/ceramides combinations: the importance to assess the nature of drug interaction beyond bulk tumor cells

One of the major assets of anticancer nanomedicine is the ability to co-deliver drug combinations, as it enables targeting of different cellular populations and/or signaling pathways implicated in tumorigenesis and thus tackling tumor heterogeneity. Moreover, drug resistance can be circumvented, for example, upon co-encapsulation and delivery of doxorubicin and sphingolipids, as ceramides. Herein, the impact of short (C6) and long (C18) alkyl chain length ceramides on the nature of drug interaction, within the scope of combination with doxorubicin, was performed in bulk triple-negative breast cancer (TNBC) cells, as well as on the density of putative cancer stem cells and phenotype, including live single-cell tracking. C6- or C18-ceramide enabled a synergistic drug interaction in all conditions and (bulk) cell lines tested. However, differentiation among these two ceramides was reflected on the migratory potential of cancer cells, particularly significant against the highly motile MDA-MB-231 cells. This effect was supported by the downregulation of the PI3K/Akt pathway enabled by C6-ceramide and in contrast with C18-ceramide. The decrease of the migratory potential enabled by the targeted liposomal combinations is of high relevance in the context of TNBC, due to the underlying metastatic potential. Surprisingly, the nature of the drug interaction assessed at the level of bulk cancer cells revealed to be insufficient to predict whether a drug combination enables a decrease in the percentage of the master regulators of tumor relapse as ALDH^+/high putative TNBC cancer stem cells, suggesting, for the first time, that it should be extended further down to this level.

Advanced Nanoengineering Approach for Target-Specific, Spatiotemporal, and Ratiometric Delivery of Gemcitabine-Cisplatin Combination for Improved Therapeutic Outcome in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an intractable malignancy with a dismal survival rate. Recent combination therapies have had a major impact on the improvement of PDAC prognosis. Nevertheless, clinically used combination regimens such as FOLFIRINOX and gemcitabine (Gem)/nab-paclitaxel still face major challenges due to lack of the safe and ratiometric delivery of multiple drugs. Here, a rationally designed mesoporous silica nanoparticle (MSN)-based platform is reported for the target-specific, spatiotemporal, ratiometric, and safe co-delivery of Gem and cisplatin (cisPt). It is shown that systemic administration of the nanoparticles results in synergistic therapeutic outcome in a syngeneic and clinically relevant genetically engineered PDAC mouse model that has rarely been used for the therapeutic evaluation of nanomedicine. This synergism is associated with a strategic engineering approach, in which nanoparticles provide redox-responsive controlled delivery and in situ differential release of Gem/cisPt drugs with the goal of overcoming resistance to Pt-based drugs. The platform is also rendered with additional tumor-specificity via a novel tumor-associated mucin1 (tMUC1)-specific antibody, TAB004. Overall, the platform suppresses tumor growth and eliminates the off-target toxicities of a highly toxic chemotherapy combination.

Cellular stress response to extremely low-frequency electromagnetic fields (ELF-EMF): An explanation for controversial effects of ELF-EMF on apoptosis

Impaired apoptosis is one of the hallmarks of cancer, and almost all of the non‐surgical approaches of eradicating tumour cells somehow promote induction of apoptosis. Indeed, numerous studies have stated that non‐ionizing non‐thermal extremely low‐frequency magnetic fields (ELF‐MF) can modulate the induction of apoptosis in exposed cells; however, much controversy exists in observations. When cells are exposed to ELF‐EMF alone, very low or no statistically significant changes in apoptosis are observed. Contrarily, exposure to ELF‐EMF in the presence of a co‐stressor, including a chemotherapeutic agent or ionizing radiation, can either potentiate or inhibit apoptotic effects of the co‐stressor. In our idea, the main point neglected in interpreting these discrepancies is “the cellular stress responses” of cells following ELF‐EMF exposure and its interplay with apoptosis. The main purpose of the current review was to outline the triangle of ELF‐EMF, the cellular stress response of cells and apoptosis and to interpret and unify discrepancies in results based on it. Therefore, initially, we will describe studies performed on identifying the effect of ELF‐EMF on induction/inhibition of apoptosis and enumerate proposed pathways through which ELF‐EMF exposure may affect apoptosis; then, we will explain cellular stress response and cues for its induction in response to ELF‐EMF exposure; and finally, we will explain why such controversies have been observed by different investigators.

3+7 Combined Chemotherapy for Acute Myeloid Leukemia: Is It Time to Say Goodbye?

PURPOSE OF REVIEW

With the recent approval of multiple new drugs for the treatment of acute myeloid leukemia (AML), the relevance of conventional treatment approaches, such as daunorubicin and cytarabine ("3+7") induction chemotherapy, has been challenged. We review the AML risk stratification, the efficacy of the newly approved drugs, and the role of "3+7".

RECENT FINDINGS

Treatment of AML is becoming more niched with specific subtypes more appropriately treated with gemtuzumab, midostaurin, and CPX-351. Although lower intensity therapies can yield high response rates, they are less efficient at preventing relapses. The only curative potential for poor-risk AML is still an allogeneic stem cell transplant. The number of AML subtypes where 3+7 alone is an appropriate therapeutic option is shrinking. However, it remains the backbone for combination therapy with newer agents in patients suitable for intensive chemotherapy.

Triple negative breast cancer and non-small cell lung cancer: Clinical challenges and nano-formulation approaches

Triple negative breast cancer (TNBC) and non-small cell lung cancer (NSCLC) are amongst the most aggressive forms of solid tumors. TNBC is highlighted by absence of genetic components of progesterone receptor, HER2/neu and estrogen receptor in breast cancer. NSCLC is characterized by integration of malignant carcinoma into respiratory system. Both cancers are associated with poor median and overall survival rates with low progression free survival with high incidences of relapse. These cancers are characterized by tumor heterogeneity, genetic mutations, generation of cancer-stem cells, immune-resistance and chemoresistance. Further, these neoplasms have been reported for tumor cross-talk into second primary cancers for each other. Current chemotherapeutic regimens include usage of multiple agents in tandem to affect tumor cells through multiple mechanisms with various such combinations being clinically tested. However, lack of controlled delivery and effective temporospatial presence of chemotherapeutics has resulted in suboptimal therapeutic response. Consequently, passive targeted albumin bound paclitaxel and PEGylated liposomal doxorubicin have been clinically used and tested with newer drugs for improved therapeutic efficacy in these cancers. Active targeting of nanocarriers against surface overexpressed proteins in both neoplasms have been explored. However, use of single agent nanoparticulate formulations against both cancers have failed to elicit desired outcomes. This review aims to identify clinical unmet need in these cancers while establishing a correlation with tested nano-formulation approaches and issues with preclinical to clinical translation. Lipid and polymer-based drug-drug and drug-gene combinatorial nanocarriers delivering multiple chemotherapeutics simultaneously to desired site of action have been detailed. Finally, emerging opportunities such as pharmacological targets (immune check point and epigentic modulators) as well as gene-based modulation (siRNA/CRISPR/Cas9) and the nano-formulation challenges for effective treatment of both cancers have been explored.

SN38 loaded nanostructured lipid carriers (NLCs); preparation and in vitro evaluations against glioblastoma

SN38 is the active metabolite of irinotecan with 1000-fold greater cytotoxicity compared to the parent drug. Despite the potential, its application as a drug is still seriously limited due to its stability concerns and low solubility in acceptable pharmaceutical solvents. To address these drawbacks here nanostructured lipid carrier (NLC) containing SN38 was prepared and its cytotoxicity against U87MG glioblastoma cell line was investigated. The formulations were prepared using hot ultrasonication and solvent evaporation/emulsification methods. NLCs with a mean size of 140 nm and particle size distribution (PDI) of 0.25 were obtained. The average loading efficiency was 9.5% and its entrapment efficiency was 81%. In order to obtain an accurate determination of released amount of SN38 a novel medium and extraction method was designed, which lead to an appropriate in vitro release profile of the drug from the prepared NLCs. The MTT test results revealed the significant higher cytotoxicity of NLCs on U87MG human glioblastoma cell line compared with the free drug. The confocal microscopy images confirmed the proper penetration of the nanostructures into the cells within the first 4 h. Consequently, the results indicated promising potentials of the prepared NLCs as a novel treatment for glioblastoma.

The Enhanced Efficacy of Intracellular Delivery of Doxorubicin/C6-Ceramide Combination Mediated by the F3 Peptide/Nucleolin System Is Supported by the Downregulation of the PI3K/Akt Pathway

Simple Summary

Targeted nanomedicine-based approaches that aim at the simultaneous delivery of synergistic drug combinations to multiple cellular populations are of high relevance for tackling heterogeneity on solid tumors. Considering that cancer stem cells (CSC) may originate from non-stem cancer cells, single-drug regimens targeting only one of these cell populations could enable tumors to evade treatments. As such, the identification of a common marker, such as nucleolin, might result in a therapeutic advantage. The results herein generated suggested a transversal role of nucleolin in the internalization of F3 peptide-targeted pegylated pH-sensitive liposomes into bulk ovarian cancer cells, including putative CSC-enriched ovarian cells. The intracellular delivery of a drug combination such as the one tested herein was relevant in the context of cell lines with higher intrinsic resistances to doxorubicin. The enhanced efficacy of the F3 peptide-targeted liposomal combination of doxorubicin/C6-ceramide was supported by the downregulation of the Akt pathway, within a specific range of basal level of expression.

Abstract

Targeting multiple cellular populations is of high therapeutic relevance for the tackling of solid tumors heterogeneity. Herein, the ability of pegylated and pH-sensitive liposomes, functionalized with the nucleolin-binding F3 peptide and containing doxorubicin (DXR)/C6-ceramide synergistic combination, to target, in vitro, ovarian cancer, including ovarian cancer stem cells (CSC), was assessed. The underlying molecular mechanism of action of the nucleolin-mediated intracellular delivery of C6-ceramide to cancer cells was also explored. The assessment of overexpression of surface nucleolin expression by flow cytometry was critical to dissipate differences identified by Western blot in membrane/cytoplasm of SKOV-3, OVCAR-3 and TOV-112D ovarian cancer cell lines. The former was in line with the significant extent of uptake into (bulk) ovarian cancer cells, relative to non-targeted and non-specific counterparts. This pattern of uptake was recapitulated with putative CSC-enriched ovarian SKOV-3 and OVCAR-3 sub-population (EpCAM^high/CD44^high). Co-encapsulation of DXR:C6-ceramide into F3 peptide-targeted liposomes improved cytotoxic activity relative to liposomes containing DXR alone, in an extent that depended on the intrinsic resistance to DXR and on the incubation time. The enhanced cytotoxicity of the targeted combination was mechanistically supported by the downregulation of PI3K/Akt pathway by C6-ceramide, only among the nucleolin-overexpressing cancer cells presenting a basal p-Akt/total Akt ratio lower than 1.

Combination of Niraparib, Cisplatin and Twist Knockdown in Cisplatin-Resistant Ovarian Cancer Cells Potentially Enhances Synthetic Lethality through ER-Stress Mediated Mitochondrial Apoptosis Pathway

Poly (ADP-ribose) polymerase 1 inhibitors (PARPi) are used to treat recurrent ovarian cancer (OC) patients due to greater survival benefits and minimal side effects, especially in those patients with complete or partial response to platinum-based chemotherapy. However, acquired resistance of platinum-based chemotherapy leads to the limited efficacy of PARPi monotherapy in most patients. Twist is recognized as a possible oncogene and contributes to acquired cisplatin resistance in OC cells. In this study, we show how Twist knockdown cisplatin-resistant (CisR) OC cells blocked DNA damage response (DDR) to sensitize these cells to a concurrent treatment of cisplatin as a platinum-based chemotherapy agent and niraparib as a PARPi on in vitro two-dimensional (2D) and three-dimensional (3D) cell culture. To investigate the lethality of PARPi and cisplatin on Twist knockdown CisR OC cells, two CisR cell lines (OV90 and SKOV3) were established using step-wise dose escalation method. In addition, in vitro 3D spheroidal cell model was generated using modified hanging drop and hydrogel scaffolds techniques on poly-2-hydroxylethly methacrylate (poly-HEMA) coated plates. Twist expression was strongly correlated with the expression of DDR proteins, PARP1 and XRCC1 and overexpression of both proteins was associated with cisplatin resistance in OC cells. Moreover, combination of cisplatin (Cis) and niraparib (Nira) produced lethality on Twist-knockdown CisR OC cells, according to combination index (CI). We found that Cis alone, Nira alone, or a combination of Cis+Nira therapy increased cell death by suppressing DDR proteins in 2D monolayer cell culture. Notably, the combination of Nira and Cis was considerably effective against 3D-cultures of Twist knockdown CisR OC cells in which Endoplasmic reticulum (ER) stress is upregulated, leading to initiation of mitochondrial-mediated cell death. In addition, immunohistochemically, Cis alone, Nira alone or Cis+Nira showed lower ki-67 (cell proliferative marker) expression and higher cleaved caspase-3 (apoptotic marker) immuno-reactivity. Hence, lethality of PARPi with the combination of Cis on Twist knockdown CisR OC cells may provide an effective way to expand the therapeutic potential to overcome platinum-based chemotherapy resistance and PARPi cross resistance in OC.

Incorporation of Novel therapies for the treatment of acute myeloid leukemia: a perspective

Acute myeloid leukemia (AML) is a heterogeneous group of diseases that poses an array of therapeutic challenges. For decades two chemotherapeutic agents, cytarabine and daunorubicin, remained the backbone of AML therapy protocols. However, since 2017 nine novel therapies have been approved for the management of AML. With the rapid expansion of therapeutic options, hematologists must adapt their practice to optimize the benefits of these novel therapy options and minimize treatment toxicity. Here, we discuss the novel therapies that have changed the standard of care in management of patients with AML. We summarize the pivotal clinical trials that lead to the approval of these agents, and ongoing trials evaluating additional potential indications. We discuss several promising therapy candidates and their corresponding clinical trials. We discuss therapeutic strategies to incorporate these therapies into practice and pose unanswered questions that have arisen along with the expansion of treatment options.

Artificial peptides for antitumoral siRNA delivery

Intracellular delivery has been critical for the success of siRNA and related therapeutic nucleic acids. Improvement of delivery carriers will positively influence the efficacy of future nanomedicines. Our strategy for optimizing siRNA nanocarriers focuses on a bioinspired sequence-defined process including (i) identification of artificial amino acids active in specific delivery steps, (ii) assembly into defined sequences by solid phase-assisted synthesis (SPS), and (iii) screening for siRNA delivery, selection of top candidates and understanding structure-activity relations, followed by (iv) sequence variation for the next round of carrier selection. In the current review, our experience with this artificial peptide evolution in tumor-directed siRNA delivery is addressed. The medium-sized oligoaminoamides show better biological compatibility and can be functionalized to meet the requirements of siRNA delivery, such as formation of stable nanoparticles, shielding against proteins in the bloodstream, targeting into tumor tissue, and intracellular siRNA release in bioactive form.

Macrocyclic-Amphiphile-Based Self-Assembled Nanoparticles for Ratiometric Delivery of Therapeutic Combinations to Tumors

Combination chemotherapy refers to the use of multiple drugs to treat cancer. In this therapy, the optimal ratio of the drugs is essential to achieve drug synergism and the desired therapeutic effects. However, most delivery strategies are unable to precisely control the ratio of the drugs during the drug loading and delivery processes, resulting in inefficient synergy and unpredictable efficacy. Herein, a macrocyclic-amphiphile-based self-assembled nanoparticle (MASN) that achieves precise loading and ratiometric delivery of therapeutic combinations is presented. By integrating multiple macrocyclic cavities within a single nanoparticle, the MASN can load multiple drug molecules via the host-guest interaction, and the ratio of the drugs loaded can be predicted with their initial concentrations and characteristic binding affinity. Moreover, MASNs are readily degraded under a hypoxic microenvironment, allowing spontaneous release of the drugs upon reaching tumor tissues. With precise drug loading and controlled release mechanisms, MASNs achieve ratiometric delivery of multiple commercial drugs to tumors, thereby achieving optimal anti-tumor effects. Since the optimal drug ratio of a therapeutic combination can be quickly determined in vitro, MASNs can translate this optimal ratio to the therapeutic benefits in vivo, providing a potential platform for the rapid development of effective combination cancer therapies involving multiple drugs.

A review of FDA-approved acute myeloid leukemia therapies beyond '7 + 3'

Introduction: The standard anthracycline and cytarabine-based chemotherapy for acute myeloid leukemia (AML) has changed relatively little since the 1970s and produces unsatisfactory outcomes in many patients. In the past two decades, a better understanding of the pathophysiology and heterogeneity of this disease has led to promising new therapies, resulting in a flurry of new drug approvals.Areas covered: The MEDLINE database, ClinicalTrials.gov and conference proceedings were reviewed for the most salient literature concerning FDA-approved drugs for AML beyond standard chemotherapy: gemtuzumab ozogamicin, hypomethylating agents, Fms-like tyrosine kinase 3 (FLT3) inhibitors, isocitrate dehydrogenase (IDH) inhibitors, venetoclax, liposomal cytarabine and daunorubicin (CPX-351), and hedgehog pathway inhibitors. Key evidence for their efficacy is discussed. For each drug category, indications, typical usage and responses, major toxicities, and future directions for research are highlighted.Expert opinion: The treatment paradigm for AML is rapidly evolving. Promising new drugs targeting driver mutations have improved outcomes in specific AML subgroups. In parallel, advances in low-intensity therapies have allowed patients unfit for standard induction chemotherapy to achieve meaningful disease control. Further work is ongoing to identify synergistic drug combinations as well as optimal treatment selection guided by individual patient and disease features.

Acute Myeloid Leukemia in Children: Emerging Paradigms in Genetics and New Approaches to Therapy

PURPOSE OF REVIEW

Acute myeloid leukemia (AML) in children remains a challenging disease to cure with suboptimal outcomes particularly when compared to the more common lymphoid leukemias. Recent advances in the genetic characterization of AML have enhanced understanding of individualized patient risk, which has also led to the development of new therapeutic strategies. Here, we review key cytogenetic and molecular features of pediatric AML and how new therapies are being used to improve outcomes.

RECENT FINDINGS

Recent studies have revealed an increasing number of mutations, including WT1, CBFA2T3-GLIS2, and KAT6A fusions, DEK-NUP214 and NUP98 fusions, and specific KMT2A rearrangements, which are associated with poor outcomes. However, outcomes are starting to improve with the addition of therapies such as gemtuzumab ozogamicin and FLT3 inhibitors, initially developed in adult AML. The combination of advanced risk stratification and ongoing improvements and innovations in treatment strategy will undoubtedly lead to better outcomes for children with AML.

Surface-engineered nanostructured lipid carrier systems for synergistic combination oncotherapy of non-small cell lung cancer

Nanoparticle-aided combination chemotherapy offers several advantages like ratiometric drug delivery, dose reduction, multi-targeted therapy, synergism, and overcoming multi-drug resistance. The current research was instigated to facilitate targeted and ratiometric co-delivery of docetaxel (DT) and curcumin (CR) through the development of folate (FA)-appended nanostructured lipid carriers (NLCs), i.e., FA-DTCR-NLCs to lung cancer cells. The FA-DTCR-NLCs were formulated by employing a scaleable and solvent-free high-pressure homogenization approach. The FA-DTCR-NLCs were evaluated for in vitro and in vivo characteristics using suitable analytical and statistical techniques. The FA-DTCR-NLCs demonstrated physicochemical properties and particokinetics suitable for targeted, ratiometric co-delivery of the anticancer agents. This was further affirmed by significantly better in vivo relative bioavailability of DT (24.85 fold) with FA-DTCR-NLCs as compared with Taxotere^® (p < 0.05) and cell line studies. A significant tumor regression was observed from the results of tumor staging in a murine model of lung carcinoma (p < 0.05). Immunostaining of the tumor sections with tumor differentiation biomarkers suggested considerably higher apoptotic, anti-proliferative, anti-angiogenic, and anti-metastatic potential of FA-DTCR-NLCs compared with Taxotere^®. In vivo toxicity assessment of the FA-DTCR-NLCs demonstrated a noteworthy reduction in DT associated side effects. The in vitro and in vivo pre-clinical findings prove the therapeutic and safety pre-eminence of FA-DTCR-NLCs for the treatment of NSCLC.

DNA-Controlled Encapsulation of Small Molecules in Protein Nanoparticles

A nanoparticle can hold multiple types of therapeutic and imaging agents for disease treatment and diagnosis. However, controlling the storage of molecules in nanoparticles is challenging, because nonspecific intermolecular interactions are used for encapsulation. Here, we used specific DNA interactions to store molecules in nanoparticles. We made nanoparticles containing DNA anchors to capture DNA-conjugated small molecules. By changing the sequences and stoichiometry of DNA anchors, we can control the amount and ratio of molecules with different chemical properties in the nanoparticles. We modified the cytotoxicity of our nanoparticles to cancer cells by changing the ratio of encapsulated drugs (mertansine and doxorubicin). Specifically controlling the storage of multiple types of molecules allows us to optimize the properties of combination drug and imaging nanoparticles.

Case Report: Allogeneic Stem Cell Transplantation Following Induction With CPX-351 in Patients With Acute Myeloid Leukemia Is Feasible

Acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) and treatment-related acute myeloid leukemia (tAML) after chemotherapy or radiation therapy for other neoplasms are associated with poor outcomes. CPX-351, a dual-drug liposomal encapsulation of daunorubicin and cytarabine, has been shown to improve outcomes in AML-MRC and tAML compared with standard 7+3 regimens. Here we report the cases of four consecutive patients with AML-MRC or tAML who received CPX-351 as outpatient induction therapy immediately followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT). Two patients received allo-HSCT in remission (one in complete remission and one in partial remission) and two patients received allo-HSCT in aplasia (one at 11 days and one at 52 days after the start of induction therapy with CPX-351). With a median follow-up of 188 days after allo-HSCT, all but one patient are alive and two are in remission. Further studies will help define and expand the role of CPX-351 in the treatment of AML-MRC and tAML, especially in patients expected to undergo allo-HSCT.

CPX-351 daunorubicin-cytarabine liposome: a novel formulation to treat patients with newly diagnosed secondary acute myeloid leukemia

Over the last few years, we assisted to an increasing knowledge about acute myeloid leukemia (AML) pathobiology. However, outcomes remain unsatisfactory particularly for adult patients over 60 years old. Not surprisingly several cases of therapy-related AML (tAML) and secondary AML, both characterized by poorer prognosis, are more common in older population. For several decades initial therapy for AML remained unchanged and typically treatment consisted of an anthracycline combined with continuous infusion of cytarabine for 7 days, the so-called "7+3" standard regimen. The efforts made by the researchers to improve this standard schedule, have led to only modest improvement in the response rate (RR) but no change in overall survival (OS), until the recent evolution seen with new target specific mutation therapies. In 2017, a new liposomal-encapsulated formulation with daunorubicin and cytarabine (CPX-351) was approved by the US Food and Drug Administration for the treatment of newly diagnosed tAML or AML with myelodysplasia-related changes (AML-MRCs). Based on the findings that ratiometric delivery may be more effective than administration of either drug at their maximum tolerated dose (MTD), CPX-351 was designed to deliver a fixed 5:1 molar ratio of the two molecules historically used in the standard "7+3" regimen, cytarabine and daunorubicin respectively. CPX-351 did show improvements of overall survival compared to traditional "7+3" in newly diagnosed secondary and therapy-related AML in adult patients. However, questions remain regarding how to select across AML patient subgroups to maximize the clinical benefit. Possible future directions include evaluating CPX-351 dose intensification, combining this liposomal formulation with targeted therapies and not least important a better understanding about the mechanism of improved responses in tAML and AML-MRC, two entities recognized to be less chemo-sensitive than other hematologic malignancies. In summary, CPX-351 offers finally something new in the landscape of AML therapy. Herein we will review the rationale behind this new drug product development, the main pharmacological characteristics, and discuss the results of clinical trials that led to its FDA approval at first and by EMA in 2018.

Nanomedicine and chemotherapeutics drug delivery: challenges and opportunities

Cancer is considered as one of the biggest threats to humans worldwide. Researchers suggest that tumour is not just a single mass, it comprises cancerous cells surrounded by noncancerous cells such as immune cells, adipocytes and cancer stem cells (CSCs) in the extracellular matrix (ECM) containing distinct components such as proteins, glycoproteins and enzymes; thus tumour microenvironment (TME) is partially complex. Multiple interactions happen in the dynamic microenvironment (ME) lead to an acidic, hypoxic and stiff ME that is considered as one of the major contributors to cancer progression and metastasis. Furthermore, TME involves in drug resistance mechanisms and affects enhanced permeability and retention (EPR) in tumours. In such a scenario, the first step to accomplish satisfying results is the identification and recognition of this ME. Then designing proper drug delivery systems can perform selectively towards cancerous cells. In this way, several targeting and stimuli/enzyme responsive drug delivery systems have been designed. More importantly, it is necessary to design a drug delivery system that can penetrate deeper into the tumours, efficiently and selectively. Various drug delivery systems such as exosomes and size-switchable nanocarriers (NCs) could decrease side effects and increase tumour treatment results by selective accumulation in tumours. In this review, TME features, current drug delivery approaches, challenges and promising strategies towards cancer treatment are discussed.