Low Bioavailability and High Immunogenicity of a New Brand of E. colil-Asparaginase with Active Host Contaminating Proteins

Targeted Polymeric Micelles System, Designed to Carry a Combined Cargo of L-Asparaginase and Doxorubicin, Shows Vast Improvement in Cytotoxic Efficacy

L-asparaginases (ASP) and Doxorubicin (Dox) are both used in the treatment of leukemia, including in combination. We have attempted to investigate if their combination within the same targeted delivery vehicle can make such therapy more efficacious. We assembled a micellar system, where the inner hydrophobic core was loaded with Dox, while ASP would absorb at the surface due to electrostatic interactions. To make such absorption stronger, we conjugated the ASP with oligoamines, such as spermine, and the lipid components of the micelle-lipoic and oleic acids-with heparin. When loaded with Dox alone, the system yielded about a 10-fold improvement in cytotoxicity, as compared to free Dox. ASP alone showed about a 2.5-fold increase in cytotoxicity, so, assuming additivity of the effect, one could expect a 25-fold improvement when the two agents are applied in combination. But in reality, a combination of ASP + Dox loaded into the delivery system produced a synergy, with a whopping 50× improvement vs. free individual component. Pharmacokinetic studies have shown prolonged circulation of micellar formulations in the bloodstream as well as an increase in the effective concentration of Dox in micellar form and a reduction in Dox accumulation to the liver and heart (which reduces hepatotoxicity and cardiotoxicity). For the same reason, Dox's liposomal formulation has been in use in the treatment of multiple types of cancer, almost replacing the free drug. We believe that an opportunity to deliver a combination of two types of drugs to the same target cell may represent a further step towards improvement in the risk-benefit ratio in cancer treatment.

Production of highly cytotoxic and low immunogenic L-asparaginase from Stenotrophomonas maltophilia EMCC2297

L-asparaginase is an important therapeutic enzyme that is frequently utilized in the chemotherapy regimens of adults as well as pediatric patients with acute lymphoblastic leukemia. However, a high rate of hypersensitivity with prolonged use has limited its utilization. Stenotrophomonas maltophilia (S. maltophilia) EMCC2297 isolate was reported as a novel and promising source for L- asparaginase. The present study aimed at the production, purification, and characterization of L- asparaginase from S. maltophilia EMCC2297 isolate. The microbial production of L-asparaginase by the test isolate could be increased by pre-exposure to chloramphenicol at 200 µg/ml concentration. S. maltophilia EMCC2297 L-asparaginase could be purified to homogeneity by ammonium sulphate precipitation and the purified form obtained by gel exclusion chromatography showed total activity of 96.4375 IU/ml and specific activity of 36.251 IU/mg protein. SDS-PAGE analysis revealed that the purified form of the enzyme is separated at an apparent molecular weight of 17 KDa. Michaelis-Menten constant analysis showed a Km value of 4.16 × 10- 2 M with L-asparagine as substrate and Vmax of 10.67 IU/ml. The antitumor activity of the purified enzyme was evaluated on different cell lines and revealed low IC50 of 2.2 IU/ml and 2.83 IU/ml for Hepatocellular cancer cell line (HepG-2), human leukemia cancer cell line (K-562), respectively whereas no cytotoxic effect could be detected on normal human lung fibroblast cells (MRC-5). However, mice treated with native L-asparaginase showed lower IgG titre compared to commercial L-asparaginase. This study highlights the promising characteristics of this enzyme making it a valuable candidate for further research and development to be an adduct in cancer chemotherapy.

Mutations in asparaginase II from E. coli and implications for inactivation and PEGylation

All clinically-used asparaginases convert L-asparagine (L-Asn) to l-aspartate (L-Asp) and l-glutamine (L-Gln) to L-glutamate (L-Glu), which has been useful in reducing bioavailable asparagine and glutamine in patients under treatment for acute lymphoblastic leukemia. The E. coli type 2 L-asparaginase (EcA2) can present different sequences among varying bacterial strains, which we hypothesized that might affect their biological function, stability and interchangeability. Here we report the analysis of two EcA2 provided by the public health system of a middle-income country. These enzymes were reported to have similar specific activity in vitro, whereas they differ in vivo. Protein sequencing by LC-MS-MS and peptide mapping by MALDI-ToF-MS of their tryptic digests revealed that Aginasa™ share similar sequence to EcA2 from E. coli strain BL21(DE3), while Leuginase™ has sequence equivalent to EcA2 from E. coli strain AS1.357. The two amino acid differences between Aginasa™ (64D and 252 T) and Leuginase™ (64 N and 252S) resulted in structural divergences in solution as accessed by small-angle X-ray scattering and molecular dynamics simulation trajectories. The conformational variability further results in dissimilar surface accessibility with major consequences for PEGylation, as well as different susceptibility to degradation by limited proteolysis. The present results reveal that the sequence variations between these two EcA2 variants results in conformational changes associated with differential conformational plasticity, potentially affecting physico-chemical and biological properties, including proteolytic and immunogenic silent inactivation.

Quality comparison of a state-of-the-art preparation of a recombinant L-asparaginase derived from Escherichia coli with an alternative asparaginase product

L-asparaginase (ASNase) is a protein that is essential for the treatment of acute lymphoblastic leukemia (ALL). The main types of ASNase that are clinically used involve native and pegylated Escherichia coli (E. coli)-derived ASNase as well as Erwinia chrysanthemi-derived ASNase. Additionally, a new recombinant E. coli-derived ASNase formulation has received EMA market approval in 2016. In recent years, pegylated ASNase has been preferentially used in high-income countries, which decreased the demand for non-pegylated ASNase. Nevertheless, due to the high cost of pegylated ASNase, non-pegylated ASNase is still widely used in ALL treatment in low- and middle-income countries. As a consequence, the production of ASNase products from low- and middle-income countries increased in order to satisfy the demand worldwide. However, concerns over the quality and efficacy of these products were raised due to less stringent regulatory requirements. In the present study, we compared a recombinant E. coli-derived ASNase marketed in Europe (Spectrila®) with an E. coli-derived ASNase preparation from India (Onconase) marketed in Eastern European countries. To assess the quality attributes of both ASNases, an in-depth characterization was conducted. Enzymatic activity testing revealed a nominal enzymatic activity of almost 100% for Spectrila®, whereas the enzymatic activity for Onconase was only 70%. Spectrila® also showed excellent purity as analyzed by reversed-phase high-pressure liquid chromatography, size exclusion chromatography and capillary zone electrophoresis. Furthermore, levels of process-related impurities were very low for Spectrila®. In comparison, the E. coli DNA content in the Onconase samples was almost 12-fold higher and the content of host cell protein was more than 300-fold higher in the Onconase samples. Our results reveal that Spectrila® met all of the testing parameters, stood out for its excellent quality and, thus, represents a safe treatment option in ALL. These findings are particularly important for low- and middle-income countries, where access to ASNase formulations is limited.

Variations in global prices of chemotherapy for childhood cancer: a descriptive analysis

Background

The stark disparity in survival for children with cancer across the world has inspired a global call to expand chemotherapy access in low and middle income countries. Among the numerous barriers to success, a paucity of reliable information regarding chemotherapy pricing hinders the ability of governments and other key stakeholders to make informed budget decisions or negotiate lower medication prices. The aim of this study was to generate comparative price information on both individual chemotherapy agents and comprehensive treatment regimens for common childhood cancers using real-world data.

Methods

Chemotherapy agents were selected based on their inclusion in the World Health Organization (WHO) Essential Medicines List for Children (EMLc) and their use in frontline regimens for the tracer cancer types prioritized by the WHO's Global Initiative for Childhood Cancer (GICC). Sources included IQVIA MIDAS data, obtained under license from IQVIA, and publicly available data from Management Sciences for Health (MSH). Data on chemotherapy prices and purchase volumes spanning 2012-2019 were aggregated according to WHO region and World Bank (WB) income classification. Cumulative chemotherapy prices for treatment regimens were compared across WB income classification.

Findings

Data representing an estimated 1.1 billion doses of chemotherapy were obtained for 97 countries: 43 high income countries (HICs), 28 upper middle income countries (UMICs), and 26 low and lower middle income countries (LLMICs). Median drug prices in HICs were 0.9-20.4 times those of UMICs and 0.9-15.5 times those of LMICs. Regimen prices were generally higher for HICs, hematologic malignancies, non-adapted protocols, and higher risk stratification or stage, albeit with notable exceptions.

Interpretation

This study represents the largest price analysis to date of chemotherapy agents used globally in childhood cancer therapy. The findings of this study form a basis for future cost-effectiveness analysis in pediatric cancer and should inform efforts of governments and stakeholders to negotiate drug prices and develop pooled purchasing strategies.

Funding

NB received funding support from the American Lebanese Syrian Associated Charities and Cancer Center Support grant (CA21765) from the National Cancer Institute through the National Institutes of Health. TA received funding through the University of North Carolina Oncology K12 (K12CA120780) and the University Cancer Research Fund from the UNC Lineberger Comprehensive Cancer Center.

A scoping review to compare and contrast quality assurance aspects of l-asparaginase biosimilars

l-asparaginase is a first-line medicine used for the treatment of acute lymphoblastic leukemia. Differing quality of marketed l-asparaginase biosimilars has been reported to adversely influence treatment outcomes. Herein, the quality of l-asparaginase biosimilars intended for clinical use was reviewed in sight of quality assurance parameters using English and Chinese language database searching, which provided information for possible improvements to the manufacture of this medicine. Ten articles met inclusion criteria, and quality attributes that measured potency, specific activity, purity and host cell proteins (HCPs) were identified. Biosimilars manufactured in high-income countries represented good quality in all aspects. Biosimilars manufactured in high-middle/middle-income countries, however, suggested poorer quality control particularly over removal of HCPs. Future work should now focus on establishing pharmacopeia monographs to establish equivalent quality assurance for l-asparaginase biosimilars manufactured between countries. Standardization of the quality profile, analytical methods and the limits of critical quality parameters, are essential to ensure appropriated efficacy and safety of clinical grade l-asparaginase.

A prospective, open-label, randomised, parallel design study of 4 generic formulations of intramuscular L-asparaginase in childhood precursor B-cell acute lymphoblastic leukaemia (ALL)

AIMS

L-asparaginase is an essential medicine for childhood ALL. The quality of generic L-asparaginase available in India is a matter of concern. We compared four commonly used generic formulations of L-asparaginase in India.

MATERIALS AND METHODS

We conducted a prospective, open-label, randomised trial of four generic formulations of asparaginase for the treatment of patients with newly diagnosed intermediate-risk B-ALL. Patients were randomly assigned in a 1:1:1:1 ratio to receive generic asparaginase at a dose of at 10,000 IU/m 2 on days 9, 12, 15, and 18 of a 35-day cycle (Induction treatment). The primary end points were to determine the difference in the asparaginase activity and asparagine depletion. Historical patients who received L-asparaginase Medac (innovator) served as controls.

RESULTS

A total of 48 patients underwent randomization; 12 patients each in the four arms. Failure to achieve predefined activity threshold of 100 IU/L was observed in 9/40 samples of Generic A (22·5%), 23/40 of Generic B (57·5%), and 43/44 (98%) each of Generic C and D. All 27 samples from seven historical patients who were administered Medac had activity > 100 IU/L. The average activity was significantly higher for Genericm A, 154 (70·3, 285·4) IU/L followed by Generic B 84·5(44·2, 289·1) IU/L, Generic C 45(14·4, 58·4) IU/L, and Generic D 20·4(13, 35) IU/L. Only 6 patients had asparaginase activity > 100 IU/L on each of the four occasions (Generic A = 5; Generic B = 1), and none of them developed Anti-Asparaginase Antibodies (AAA). On the other hand, AAA was observed in 12/36 patients who had at least one level < 100 IU/L (P < 0·05): Generic A 3/5, Generic B = 3/9, Generic D (4/11), and Generic C (5/11).

CONCLUSION

Generic A and B had better trough asparaginase activity compared to Generic D and C. Overall, generic formulations had lower asparaginase activity which raises serious clinical concerns regarding their quality. Until strict regulatory enforcement improves the quality of these generics, dose adaptive approaches coupled with therapeutic drug monitoring need to be considered.

Pharmacological and clinical monitoring in children with acute lymphoblastic leukemia treated with a biogeneric PEG-l-asparaginase product

BACKGROUND

l-Asparaginase (ASP) plays a crucial role in the treatment of childhood acute lymphoblastic leukemia (ALL). Currently, different ASP products are available in the market, including both native and pegylated drugs. Several biogeneric Escherichia coli ASP (GEN-ASP) products have been developed in response to shortages and expensiveness of the native E. coli ASP innovator compounds, but some concerns have been raised about their quality. Recently, a number of generic pegylated ASP products (GEN-PEG-ASP) have been marketed to substitute for the innovator product (PEG-ASP).

METHODS

Clinical courses and serum asparaginase activity (SAA) levels were monitored in 12 children with ALL, who were treated in our institution with two doses of a GEN-PEG-ASP product, given IV at 2500 IU/m² during the remission induction phase. Results were compared with those obtained in a reference cohort of 35 patients treated in our institution, who received the innovator PEG-ASP product at same dosage and within the same chemotherapy background.

RESULTS

Compared to the reference cohort treated with PEG-ASP, SAA levels were significantly lower in the 12 patients receiving GEN-PEG-ASP (p < .0001); a higher proportion of ASP-associated hypersensitivity reactions (2/12 vs. 0/35; p = .061) and silent inactivation (3/12 vs. 0/35; p = .014) were observed in comparison with the reference cohort.

CONCLUSIONS

Our results highlighted different pharmacological profiles and different rates of hypersensitivity reactions and silent inactivation in the GEN-PEG-ASP cohort compared to those treated with the innovator product. Our findings suggest that a rigorous clinical attention and a thorough pharmacological monitoring are advisable in patients treated with GEN-PEG-ASP products.

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.

Unsatisfactory quality of E. coli asparaginase biogenerics in India: Implications for clinical outcomes in acute lymphoblastic leukaemia

BACKGROUND

The biotherapeutic asparaginase is a cornerstone of therapy in acute lymphoblastic leukaemia (ALL). With limited access to the original native Escherichia coli-derived asparaginase (EcASNase), a variety of EcASNase biogenerics are used in low-middle-income countries (LMICs). The variable quality of these biogenerics potentially influences clinical outcomes.

PROCEDURE

Seven biogeneric EcASNases (P1-P7) marketed widely in India were evaluated, with P2 as an exemplar for in vivo monitoring. Therapeutic activity of P2 (10,000 IU/m² /dose, intramuscular, every 72 hours) was monitored during induction therapy, and drug-related toxicities recorded. Molecular identity, purity and in vitro drug activity of seven biogenerics were characterised using multimodal analyses, and findings compared with reference EcASNase (R).

RESULTS

In patients (N = 62) receiving P2, subtherapeutic asparaginase activity (<100 U/L) was observed in 66% (46/70) of trough timepoints (72 hours postdose) during induction. Twelve patients (19%), 11 with high-risk ALL, developed hypersensitivity. Isoforms of EcASNase were identified in all seven biogenerics. All generic products contained impurities with batch-to-batch variability. These included high levels of protein aggregates and host cell protein contamination. In vitro assays of EcASNase activity and leukaemia cell line cytotoxicity were not discriminatory.

CONCLUSIONS

Our findings confirm widespread concerns over the unsatisfactory quality and therapeutic activity of native EcASNase biogenerics marketed in LMICs. Appropriate use of these products requires monitored studies to identify clinical suitability and determine appropriate dosing and schedule. For large parts of the world, assured access to high-quality asparaginases remains an unmet therapeutic need.

Microbial production, molecular modification, and practical application of l-Asparaginase: A review

L-Asparaginase (L-ASNase, EC 3.5.1.1), an antitumor drug for acute lymphoblastic leukemia (ALL) therapy, is widely used in the clinical field. Similarly, L-ASNase is also a powerful and significant biological tool in the food industry to inhibit acrylamide (AA) formation. This review comprehensively summarizes the latest achievements and improvements in the production, modification, and application of microbial L-ASNase. To date, the expression levels and optimization of expression hosts such as Escherichia coli, Bacillus subtilis, and Pichia pastoris, have made significant progress. In addition, examples of successful modification of L-ASNase such as decreasing glutaminase activity, increasing the in vivo stability, and enhancing thermostability have been presented. Impressively, the application of L-ASNase as a food addition aid, as well as its commercialization in the pharmaceutical field, and cutting-edge biosensor application developments have been summarized. The presented results and proposed ideas could be a good guide for other L-ASNase researchers in both scientific and practical fields.

Influence of different asparaginase formulations in the prognosis of children with acute lymphocytic leukaemia in Brazil: a multicentre, retrospective controlled study

Our group recently showed that the (ASNase) formulation available in Brazil from 2017 to 2018 when used at the same dose and frequency as the formulation provided previously did not reach the activity considered therapeutic. Based on these, our goal was to assess the impact of these facts on the prognosis of children with ALL at different oncology centers. A multicentre retrospective observational study followed by a prospective follow-up. Patients aged >1 and <18 years in first-line treatment followed up at 10 referral centres, between 2014 and 2018 who received the formulation Leuginase^® were identified (Group B). For each patient, the centre registered 2 patients who received ASNase in the presentation of Aginasa^® exclusively (Group A). Data collection was registered using (Redcap^® ). A total of 419 patients were included; 282 in Group A and 137 in B. Group A had a 3-year OS and EFS of 91·8% and 84·8% respectively, while Group B had a 3-year OS of 83·8% (P = 0·003) and EFS of 76·1% (P = 0·008). There was an impact on 3-year OS and EFS of children who received a formulation. This result highlights the importance of evaluating ASNase and monitoring its activity.

Biophysical characterization of two commercially available preparations of the drug containing Escherichia coli L-Asparaginase 2

The hydrolysis of asparagine and glutamine by L-asparaginase has been used to treat acute lymphoblastic leukemia for over four decades. Each L-asparaginase monomer has a long loop that closes over the active site upon substrate binding, acting as a lid. Here we present a comparative study of two commercially available preparations of the drug containing Escherichia coli L-Asparaginase 2 (EcA2), performed by a comprehensive array of biophysical and biochemical approaches. We report the oligomeric landscape and conformational and dynamic plasticity of E. coli type 2 L-asparaginase present in two different formulations, and its relationship with L-aspartic acid, which is present in Aginasa, but not in Leuginase. The L-Asp present in Aginasa formulation was found to provide to EcA2 a resistance to in vitro proteolysis. EcA2 shows a composition of monomers and oligomers up to tetramers, which is mostly not altered in the presence of L-Asp. Ion-mobility spectrometry-mass spectrometry reveals two conformers for the monomeric EcA2, and that monomeric species has sufficient capacity for selective binding to L-Asp and L-Glu. The N-terminal loop of the EcA2 present in Leuginase, which is part of the active site is disordered, but it gets ordered in the presence of L-Asp, while L-Glu only does so to a limited extent. These data provide new insights on the mechanistic of ligand recognition by EcA2, and the impact of formulation in its conformational diversity landscape.

Shortages and price variability of essential cytotoxic medicines for treating children with cancers

Introduction

Low-income and middle-income countries (LMICs) face the largest burden of mortality from childhood cancers with limited access to curative therapies. Few comparative analyses across all income groups and world regions have examined the availability and acquisition costs of essential medicines for treating cancers in children.

Methods

A cross-sectional survey involved countries in five income groups—low-income (LIC), lower-middle-income (LMC), upper-middle-income (UMC), two high-income country groups (HIC1, HIC2). Physicians and pharmacists reported institutional use, availability, stock outs and prices (brand and generic products) of 34 essential medicines. Price comparisons used US$, applying foreign exchange rates (XR) and purchasing power parity (PPP) adjustments. Medicine costs for treating acute lymphoblastic leukaemia (ALL), Burkitt lymphoma (BL) and Wilms tumour (WT) were calculated (child 29 kg, body surface area 1 m²). Comparisons were conducted using non-parametric Kruskal-Wallis tests.

Results

Fifty-eight respondents (50 countries) provided information on medicine use, availability and stock outs, with usable price data from 42 facilities (37 countries). The extent of use of International Society of Paediatric Oncology core and ancillary medicines varied across income groups (p<0.0001 and p=0.0002 respectively). LMC and LIC facilities used fewer medicines than UMC and HIC facilities. UMC and LMC facilities were more likely to report medicines not available or stockouts.

Medicine prices varied widely within and between income bands; generic products were not always cheaper than brand equivalents. PPP adjustment showed relatively higher prices in UMC and LMC facilities for some medicines. Medicine costs were highest in HICs for ALL (p=0.0075 XR; p=0.0178 PPP-adjusted analyses) and WT (p =<0.0001 XR; p=0.0007 PPP-adjusted). Medicine costs for BL were not significantly different.

Conclusion

Problems with the availability of essential medicines, dependable supply chains, confidential medicine prices and wide variability in treatment costs contribute to persistent challenges in the care of children with treatable cancers, especially in LMICs.

Influence of lysosomal protease sensitivity in the immunogenicity of the antitumor biopharmaceutical asparaginase

L-asparaginase (ASNase) from Escherichia coli (EcAII) is used in the treatment of acute lymphoblastic leukaemia (ALL). EcAII activity in vivo has been described to be influenced by the human lysosomal proteases asparaginyl endopeptidase (AEP) and cathepsin B (CTSB); these hydrolases cleave and could expose epitopes associated with the immune response against EcAII. In this work, we show that ASNase resistance to CTSB and/or AEP influences the formation of anti-ASNase antibodies, one of the main causes of hypersensitivity reactions in patients. Error-prone polymerase chain reaction was used to produce variants of EcAII more resistant to proteolytic cleavage by AEP and CTSB. The variants with enzymatic activity and cytotoxicity levels equivalent to or better than EcAII WT were submitted to in vivo assays. Only one of the mutants presented increased serum half-life, so resistance to these proteases is not the only feature involved in EcAII stability in vivo. Our results showed alteration of the phenotypic profile of B cells isolated after animal treatment with different protease-resistant proteoforms. Furthermore, mice that were exposed to the protease-resistant proteoforms presented lower anti-asparaginase antibodies production in vivo. Our data suggest that modulating resistance to lysosomal proteases can result in less immunogenic protein drugs.

Review of nutritional status, body composition, and effects of antineoplastic drug disposition

The overall survival for children with cancer in high income countries is excellent. However, there are many disparities that may negatively affect survival, which are particularly problematic in low income countries, such as nutritional status at diagnosis and throughout therapy. Nutritional status as well as concomitant foods, supplements, and medications may play a role in overall exposure and response to chemotherapy. Emerging science around the microbiome may also play a role and should be further explored as a contributor to disease progression and therapeutic response. This article highlights some of these issues and proposes additional areas of research relevant to nutritional status and pharmacology that are needed in pediatric oncology.

A comparison of asparaginase activity in generic formulations of E.coli derived L- asparaginase: In-vitro study and retrospective analysis of asparaginase monitoring in pediatric patients with leukemia

AIMS

L-asparaginase is an essential medicine in the treatment of pediatric acute lymphoblastic leukemia (ALL) and the quality of generic formulations is an area of concern. We compared nine generic formulations of L-asparaginase available in India with the innovator.

METHODS

The quality of formulations was assessed by measuring 72-hour trough asparaginase activity in children with ALL during induction following administration of 10,000 IU/m² of L-asparaginase. In-vitro analysis of the label claim was assessed by measuring activity of three generic formulations. Liquid chromatography-mass spectrometry (LC/MS) was used to determine the amount of host contaminant proteins (HCPs) in the formulations.

RESULTS

Between March 2015 to June 2018, 240 samples from 195 patients were analyzed. The number of samples analyzed ranged from 7-66 per generic brand (median: 18) and seven of the innovator. The proportion of generic formulations that failed to achieve a predefined clinical threshold activity of 50 IU/L ranged from 16.7% (2/12) to 84.9% (28/33) in the highest activity to lowest activity generic respectively. On other hand, all innovator samples had activity greater than 50 IU/L. In-vitro asparaginase activity in the three generic formulations tested ranged from 71.4-74.6% of the label claim (10,000 IU) compared to 93.5% for the innovator. LC/MS analysis of generic 5 identified 25 HCPs with a relative peptide count of 27.1% of the total peptides.

CONCLUSIONS

Generic formulations had lower asparaginase activity which raises serious clinical concerns regarding their quality. Until stringent regulatory enforcement improves the quality of these generics, dose adaptive strategies coupled with therapeutic drug monitoring need to be considered.

Allergic reactions to asparaginase: retrospective cohort study in pediatric patients with acute lymphoid leukemia

INTRODUCTION

To assess the frequency of allergic reactions to asparaginase (ASP) and possible risk factors for reactions in a cohort of pediatric patients.

METHOD

The study was performed based on retrospective data from patients under acute lymphoid leukemia treatment in a general university hospital located in southern Brazil. Information on patients who used ASP from 2010 to 2017 was collected. Allergic reactions were identified in electronic medical records.

RESULTS

Among the 98 patients included in the study, 16 (16.3 %) experienced an allergic reaction to native l-asparaginase (L-ASP). Of the 22 patients (22.4 %) that received only intravenous (IV) administration of l-ASP, 10 (62.5 %) had allergic reactions, while 48 patients (49 %) received intramuscular (IM) administration and 28 (28.6 %) received IV and IM administrations. The occurrence of allergic reactions differed between the groups (p <  0.001), and IV administration was associated with allergic reactions. Association was also observed between the severity of the reaction and the route of administration, with the IM route associated with grade 2 and IV route associated with grade 3. Occurrence of allergic reactions was higher when the commercial formulation of l-ASP, Leuginase®, was used (p =  0.0009 in the analysis per patient and p =  0.0003 in the analysis per administration).

CONCLUSIONS

The IV administration and commercial Leuginase® presentation were associated with more allergic reactions in the study population, which corroborates the findings in the literature. The IV route was also associated with higher severity of reactions in the present study.

Global Access to Essential Medicines for Childhood Cancer: A Cross-Sectional Survey

Purpose

Global data mapping access to essential chemotherapeutics for pediatric cancer are scarce. We report a survey of international pediatric cancer care providers’ access to these medicines.

Methods

A Web-based survey was sent to pediatric oncologists registered on the Cure4Kids Web portal. We queried chemotherapeutics in the WHO Essential Medicines List for Children, from which the average proportional availability was summarized as each country’s access score. In addition, we examined availability of drug packages defined by the WHO-sanctioned Expert Committee for eight pediatric cancers. We undertook a sensitivity analysis investigating how regimen access would change if the cytotoxics specified in recent agreements between the Clinton Health Access Initiative, American Cancer Society, and pharmaceutical companies were universally available.

Results

There were significant (P < .001) differences in the median access scores between World Bank income groups, and 42.9% of respondents from low-income and lower middle–income countries reported suboptimal access scores. Our disease-based analysis revealed that 42.1% of patients in low-income and lower middle–income countries lacked full access to chemotherapy packages. Guaranteed availability of the cytotoxics specified in the Clinton Health Access Initiative/American Cancer Society agreements was projected to increase this regimen-based access by 1.6%, although including four additional chemotherapeutics would further increase coverage by 13.9%.

Conclusion

This study is the first, to our knowledge, to assess worldwide variation in practical access to pediatric chemotherapy. Although mapping the proportion of available chemotherapeutics is informative, we also developed a meaningful estimate of access using disease-specific drug packages. These data provide an important baseline for continued monitoring and can aid in planning adaptive treatment guidelines that consider the trade-offs between access and outcomes.

Science and health for all children with cancer

Each year ~429,000 children and adolescents aged 0 to 19 years are expected to develop cancer. Five-year survival rates exceed 80% for the 45,000 children with cancer in high-income countries (HICs) but are less than 30% for the 384,000 children in lower-middle-income countries (LMICs). Improved survival rates in HICs have been achieved through multidisciplinary care and research, with treatment regimens using mostly generic medicines and optimized risk stratification. Children’s outcomes in LMICs can be improved through global collaborative partnerships that help local leaders adapt effective treatments to local resources and clinical needs, as well as address common problems such as delayed diagnosis and treatment abandonment. Together, these approaches may bring within reach the global survival target recently set by the World Health Organization: 60% survival for all children with cancer by 2030.

Development of L-Asparaginase Biobetters: Current Research Status and Review of the Desirable Quality Profiles

L-Asparaginase (ASNase) is a vital component of the first line treatment of acute lymphoblastic leukemia (ALL), an aggressive type of blood cancer expected to afflict over 53,000 people worldwide by 2020. More recently, ASNase has also been shown to have potential for preventing metastasis from solid tumors. The ASNase treatment is, however, characterized by a plethora of potential side effects, ranging from immune reactions to severe toxicity. Consequently, in accordance with Quality-by-Design (QbD) principles, ingenious new products tailored to minimize adverse reactions while increasing patient survival have been devised. In the following pages, the reader is invited for a brief discussion on the most recent developments in this field. Firstly, the review presents an outline of the recent improvements on the manufacturing and formulation processes, which can severely influence important aspects of the product quality profile, such as contamination, aggregation and enzymatic activity. Following, the most recent advances in protein engineering applied to the development of biobetter ASNases (i.e., with reduced glutaminase activity, proteolysis resistant and less immunogenic) using techniques such as site-directed mutagenesis, molecular dynamics, PEGylation, PASylation and bioconjugation are discussed. Afterwards, the attention is shifted toward nanomedicine including technologies such as encapsulation and immobilization, which aim at improving ASNase pharmacokinetics. Besides discussing the results of the most innovative and representative academic research, the review provides an overview of the products already available on the market or in the latest stages of development. With this, the review is intended to provide a solid background for the current product development and underpin the discussions on the target quality profile of future ASNase-based pharmaceuticals.