A Phase 3, multicenter, open-label, switchover trial to assess the safety and efficacy of taliglucerase alfa, a plant cell-expressed recombinant human glucocerebrosidase, in adult and pediatric patients with Gaucher disease previously treated with imiglucerase

A Critical Analysis of the FDA's Omics-Driven Pharmacodynamic Biomarkers to Establish Biosimilarity

Demonstrating biosimilarity entails comprehensive analytical assessment, clinical pharmacology profiling, and efficacy testing in patients for at least one medical indication, as required by the U.S. Biologics Price Competition and Innovation Act (BPCIA). The efficacy testing can be waived if the drug has known pharmacodynamic (PD) markers, leaving most therapeutic proteins out of this concession. To overcome this, the FDA suggests that biosimilar developers discover PD biomarkers using omics technologies such as proteomics, glycomics, transcriptomics, genomics, epigenomics, and metabolomics. This approach is redundant since the mode-action-action biomarkers of approved therapeutic proteins are already available, as compiled in this paper for the first time. Other potential biomarkers are receptor binding and pharmacokinetic profiling, which can be made more relevant to ensure biosimilarity without requiring biosimilar developers to conduct extensive research, for which they are rarely qualified.

Real-World Experiences with Taliglucerase Alfa Home Infusions for Patients with Gaucher Disease: A Global Cohort Study

Taliglucerase alfa is an enzyme replacement therapy approved for Gaucher disease. We assessed the duration/compliance/safety of such home infusions in commercial use in four countries where home infusion programs are available. The treatment duration/compliance study included 173 patients (Israel, 58; US, 61; Brazil, 48; Australia, 6) who received ≥1 taliglucerase alfa home infusion through 6/2021. The median age at home therapy initiation was 38 (range, 2-87) years; 58% were females. The median treatment duration (at home) was 2.7 (range, 0.04-9.0) years. The annual compliance rate was stable (≥95%) throughout the study period. A search of the Pfizer global safety database (through 6/2021), identified 19 adverse events (AEs) as related to "definite home use" and 14 to "possible home use" of taliglucerase alfa; 42.4% of these AEs were serious; none were fatal. Twelve serious AEs in five separate case reports were considered treatment related: one case of chest discomfort/pain and hypertension and one case of erythema associated with a toe blister, for which causality could not be excluded; pain in extremity; projectile vomiting and chills, alongside excessive eye blinking; and an infusion-related AE (pruritus). In conclusion, this real-life global study demonstrated that taliglucerase alfa home infusions are safe with high compliance rates.

Joint manifestations revealing inborn metabolic diseases in adults: a narrative review

Inborn metabolic diseases (IMD) are rare conditions that can be diagnosed during adulthood. Patients with IMD may have joint symptoms and the challenge is to establish an early diagnosis in order to institute appropriate treatment and prevent irreversible damage. This review describes the joint manifestations of IMD that may be encountered in adults. The clinical settings considered were arthralgia and joint stiffness as well as arthritis. Unspecific arthralgias are often the first symptoms of hereditary hemochromatosis, chronic low back pain may reveal an intervertebral disc calcification in relation with alkaptonuria, and progressive joint stiffness may correspond to a mucopolysaccharidosis or mucolipidosis. Gaucher disease is initially revealed by painful acute attacks mimicking joint pain described as "bone crises". Some IMD may induce microcrystalline arthropathy. Beyond classical gout, there are also gouts in connection with purine metabolism disorders known as "enzymopathic gouts". Pyrophosphate arthropathy can also be part of the clinical spectrum of Gitelman syndrome or hypophosphatasia. Oxalate crystals arthritis can reveal a primary hyperoxaluria. Destructive arthritis may be indicative of Wilson's disease. Non-destructive arthritis may be seen in mevalonate kinase deficiency and familial hypercholesterolemia.

A Systematic Review and Meta-analyses of Longitudinal Studies on Drug Treatments for Gaucher Disease

OBJECTIVE

Gaucher disease (GD) is a rare disorder linked to the absence/deficiency of glucocerebrosidase. GD can be treated by enzyme replacement therapy (ERT) and substrate reduction therapy (SRT). The aim of this systematic review (SR) is to assess the effectiveness of drugs used for GD treatment.

DATA SOURCES

Searches were conducted in PubMed and Scopus, in April 2021. The search strategies encompassed the name of the disease and of the drug treatments. Manual search was also conducted.

STUDY SELECTION AND DATA EXTRACTION

Observational and interventional longitudinal studies evaluating ERT and SRT for GD were included. Single mean meta-analyses were conducted for each drug using R.

DATA SYNTHESIS

The initial search retrieved 2246 articles after duplicates were removed. Following screening and eligibility assessment, 68 reports were included. The studies evaluated imiglucerase, velaglucerase alfa, taliglucerase alfa, miglustat, and eliglustat. The results showed that ERT is effective as a treatment in both naïve and experienced patients. Miglustat did not significantly improve blood outcomes in naïve patients and resulted in a decrease in the platelet levels of experienced patients. Eliglustat was mainly assessed for experienced patients and resulted in stable outcome values.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This extensive SR confirms the effectiveness of GD treatments in short- and long-term follow-ups.

CONCLUSIONS

The results were favorable for all ERTs and for eliglustat. Based on the assessed evidence, miglustat did not achieved expressive results. However, all evidence should be interpreted considering its limitations and does not replace well-conducted randomized trials.

Real-Life Experience with Oral Eliglustat in Patients with Gaucher Disease Previously Treated with Enzyme Replacement Therapy

Three types of enzyme replacement therapies (ERTs) and two substrate reduction therapies (SRTs) are approved for symptomatic patients with type 1 Gaucher disease (GD1). Eliglustat is the second SRT approved, yet the first to be approved as first-line therapy for any adult patients with compatible CYP2D6 metabolizer genotype. Herein we report safety and efficacy data of the first 29 patients switched from ERT to eliglustat from the Gaucher Unit at Shaare Zedek Medical Center (SZMC) between 07/2017 and 06/2022; the median (range) time on ERT was 13 (0.66-30) years, and the median (range) time on eliglustat was 7 (1-52) months. Most patients switched due to oral preference or sub-optimal response to low-dose ERT. Twelve patients stopped eliglustat after a median (range) of 4 (1-18) months; 11 due to adverse events (AEs) and one due to personal request. There were no drug-related serious AEs and no drug-related cardiac events. Most AEs were mild and transient, mainly dyspepsia. Efficacy achievements were reflected by maintaining stability. We concluded that switching from ERT to eliglustat is safe if choosing the appropriate patients. Reassuring patients to tolerate early AEs may reduce discontinuation. Following the response and compliance to therapy is important to ensure long-term efficacy.

The diagnosis and management of Gaucher disease in pediatric patients: Where do we go from here?

Gaucher disease (GD) is an autosomal recessive inherited lysosomal storage disease that often presents in early childhood and is associated with damage to multiple organ systems. Many challenges associated with GD diagnosis and management arise from the considerable heterogeneity of disease presentations and natural history. Phenotypic classification has traditionally been based on the absence (in type 1 GD) or presence (in types 2 and 3 GD) of neurological involvement of varying severity. However, patient management and prediction of prognosis may be best served by a dynamic, evolving definition of individual phenotype rather than by a rigid system of classification. Patients may experience considerable delays in diagnosis, which can potentially be reduced by effective screening programs; however, program implementation can involve ethical and practical challenges. Variation in the clinical course of GD and an uncertain prognosis also complicate decisions concerning treatment initiation, with differing stakeholder perspectives around efficacy and acceptable cost/benefit ratio. We review the challenges faced by physicians in the diagnosis and management of GD in pediatric patients. We also consider future directions and goals, including acceleration of accurate diagnosis, improvements in the understanding of disease heterogeneity (natural history, response to treatment, and prognosis), the need for new treatments to address unmet needs for all forms of GD, and refinement of the tools for monitoring disease progression and treatment efficacy, such as specific biomarkers.

Safety and effectiveness of taliglucerase alfa in patients with Gaucher disease: an interim analysis of real-world data from a multinational drug registry (TALIAS)

Background

Limited real-world data from routine clinical care are available on the safety and effectiveness of treatment with taliglucerase alfa in patients with Gaucher disease (GD).

Methods

Taliglucerase Alfa Surveillance (TALIAS), a multinational prospective Drug Registry of patients with GD, was established to evaluate the long-term safety (primary objective) and effectiveness (secondary objective) of taliglucerase alfa. We present an interim analysis of the data from the Drug Registry collected over the 5-year period from September 2013 to January 2019.

Results

A total of 106 patients with GD (15.1% children aged < 18 years; 53.8% females) treated with taliglucerase alfa have been enrolled in the Drug Registry, as of January 7, 2019. The median duration of follow-up was 795 days with quartiles (Q1, Q3) of 567 and 994 days. Fifty-three patients (50.0%) were from Israel, 28 (26.4%) were from the United States, and 25 (23.6%) were from Albania. At the time of enrollment, most patients (87.7%) had received prior enzyme replacement therapy (ERT). Thirty-nine of the 106 patients had treatment-emergent adverse events (AEs). Twelve of the 106 patients experienced serious AEs; two patients experienced four treatment-related serious AEs. Four patients died, although none of the deaths was considered to be related to taliglucerase alfa treatment by the treating physicians. Nine patients discontinued from the study, including the four who died. At baseline, patients with prior ERT had a higher mean hemoglobin concentration and platelet counts than treatment-naïve patients, likely reflecting the therapeutic effects of prior treatments. During follow-up, the hemoglobin concentration and platelet counts increased in the treatment-naïve patients and remained relatively constant or increased slightly in patients with prior ERT. Spleen and liver volumes decreased in treatment-naïve patients.

Conclusions

The interim data showed no new or emergent safety signals. The overall interim data are consistent with the clinical program experience and known safety and effectiveness profile of taliglucerase alfa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02289-7.

Plant molecular farming for the production of valuable proteins - Critical evaluation of achievements and future challenges

Recombinant proteins play an important role in many areas of our lives. For example, recombinant enzymes are used in the food and chemical industries and as high-quality proteins for research, diagnostic and therapeutic applications. The production of recombinant proteins is still dominated by expression systems based on microbes and mammalian cells, although the manufacturing of recombinant proteins in plants - known as molecular farming - has been promoted as an alternative, cost-efficient strategy for three decades. Several molecular farming products have reached the market, but the number of success stories has been limited by industrial inertia driven by perceptions of low productivity, the high cost of downstream processing, and regulatory hurdles that create barriers to translation. Here, we discuss the technical and economic factors required for the successful commercialization of molecular farming, and consider potential future directions to enable the broader application of production platforms based on plants.

Hepatitis B core-based virus-like particles: A platform for vaccine development in plants

Virus-like particles (VLPs) are a class of structures formed by the self-assembly of viral capsid protein subunits and contain no infective viral genetic material. The Hepatitis B core (HBc) antigen is capable of assembling into VLPs that can elicit strong immune responses and has been licensed as a commercial vaccine against Hepatitis B. The HBc VLPs have also been employed as a platform for the presentation of foreign epitopes to the immune system and have been used to develop vaccines against, for example, influenza A and Foot-and-mouth disease. Plant expression systems are rapid, scalable and safe, and are capable of providing correct post-translational modifications and reducing upstream production costs. The production of HBc-based virus-like particles in plants would thus greatly increase the efficiency of vaccine production. This review investigates the application of plant-based HBc VLP as a platform for vaccine production.

Accuracy of chitotriosidase activity and CCL18 concentration in assessing type I Gaucher disease severity. A systematic review with meta-analysis of individual participant data

Chitotriosidase activity and CCL18 concentration are interchangeably used for monitoring Gaucher disease (GD) activity, together with clinical assessment. However, comparative studies of these two biomarkers are scarce and of limited sample size. The aim of this systematic review with meta-analysis of individual participant data (IPD) was to compare the accuracy of chitotriosidase activity and CCL18 concentration for assessing type I GD severity. We identified cross-sectional and prospective cohort studies by searching Medline, EMBASE, and CENTRAL from 1995 to June 2017, and by contacting research groups. The primary outcome was a composite of liver volume >1.25 multiple of normal (MN), spleen volume >5 MN, hemoglobin concentration <11 g/dL, and platelet count <100x109/L. Overall, IPD included 1109 observations from 334 patients enrolled in nine primary studies, after excluding 111 patients with undocumented values and 18 patients with deficient chitotriosidase activity. IPD were unavailable for 14 eligible primary studies. The primary outcome was associated with a 5.3-fold (95% confidence interval [CI], 4.2 to 6.6) and 3.0-fold (95% CI, 2.6 to 3.6) increase of the geometric mean for chitotriosidase activity and CCL18 concentration, respectively. The corresponding areas under the receiver operating characteristics curves were 0.82 and 0.84 (summary difference, 0.02, 95% CI, -0.02 to 0.05). The addition of chitotriosidase activity did not improve the accuracy of CCL18 concentration. Estimates remained robust in the sensitivity analysis and consistent across subgroups. Neither chitotriosidase activity nor CCL18 concentration varied significantly according to a recent history of bone events among 97 patients. In conclusion, CCL18 concentration is as accurate as chitotriosidase activity in assessing hematological and visceral parameters of GD severity and can be measured in all GD patients. This meta-analysis supports the use of CCL18 rather than chitotriosidase activity for monitoring GD activity in routine practice.

Evaluation of the efficacy and safety of the biosimilar drug Glurazyme (imiglucerase) in patients with Gaucher disease type 1

Background. Gaucher disease (GD) is a rare hereditary condition, which represents the most common form of lysosomal storage diseases. Enzyme replacement therapy (ERT) with recombinant glucocerebrosidase is used for the treatment of type 1 and type 3 GD. Imiglucerase (recombinant glucocerebrosidase) is the first biotechnological ERT medication possessing confirmed clinical efficacy and safety.

Aim. To compare the efficacy and safety of the biosimilar drug Glurazyme and the reference drug Cerezyme during ERT therapy in patients with type 1 GD.

Materials and methods. Thirty patients aged from 19 to 63 years (33 ± 9.7 years) with a stable course of type 1 GD were enrolled in the study. The patients were randomly divided into two equal treatment groups, one of which received Glurazyme and the other received the reference drug Cerezyme. In both groups, the drugs were used in doses of 15–40 U/kg intravenously once every 14 days for 52 weeks.

Results. At the end of the study, at week 52 (primary endpoint of efficacy), both groups demonstrated a similar increase in hemoglobin concentration compared to the baseline data. In both groups, the average increase in hemoglobin concentration was 4.8 g/l, with this parameter varying between the groups by 0.1 g/l. At week 52, the calculated 95% confidence interval for the difference in hemoglobin concentration did not cross the non-inferiority margin of 18 g/l, which had been specified as the lower level of drug efficacy. This led to the conclusion that the studied drug Glurazyme is not inferior to Cerezyme in terms of efficacy. A comparison of the treatment groups by secondary endpoints of efficacy revealed: no decrease in hemoglobin concentration by more than 20 % in both groups; no differences between the groups by the number of patients with a change in platelet concentration relative to the baseline values; no increase in the spleen and liver volume by more than 20 and 10 %, respectively, in both groups. The doses of the drug under study and the reference drug remained unchanged during the research. The concentration of chemokine CCL-18 decreased slightly in 10 patients (64.3 %) and 6 patients (40 %) in the Glurazyme group and the Cerezyme group, respectively. The proportion of patients with improved physical and mental health components was 57.1 and 57.1 %, respectively, in the Glurazyme group compared to 73.3 and 60 %, respectively, in the Cerezyme group. Changes in the state of the bone tissue and the reserves of accumulated metabolites in the bone marrow showed a similar decrease in the severity of bone marrow infiltration in both groups.

Conclusions. Glurazyme and Cerezyme showed comparable parameters of efficacy and safety in patients with GD type 1 during long-term enzyme replacement therapy.

Open-label, expanded access study of taliglucerase alfa in patients with Gaucher disease requiring enzyme replacement therapy

A multicenter, open-label, expanded-access study followed the safety of taliglucerase alfa, a plant cell-expressed recombinant enzyme replacement therapy (ERT), in adults with Gaucher disease previously treated with imiglucerase. Patients received taliglucerase alfa every 2 weeks for 9 months at a dose equivalent to their previous imiglucerase dose (Part A); patients were offered treatment for up to 33 months (Part B), and a later amendment allowed treatment-naïve patients. Fifty-eight patients received taliglucerase alfa (55.2% male; mean age, 46.1 years; mean bi-weekly dose, 35.2 U/kg; mean duration, 17.8 months); 51 patients previously received ERT, seven were treatment-naïve, and 36 completed the study. Most adverse events were mild or moderate; treatment-related adverse events were mild and transient. In previously treated patients, increases from baseline to last follow-up were observed for mean ± SE hemoglobin concentration (13.0 ± 0.3 g/dL to 13.4 ± 0.2 g/dL) and platelet count (179,242 ± 15,344/mm³ to 215,242 ± 17,867/mm³). Findings were similar in treatment-naïve patients (mean ± SE hemoglobin concentration and platelet count, 12.8 ± 0.3 g/dL to 13.5 ± 0.2 g/dL and 168,821 ± 14,368/mm³ to 204,641 ± 16,071/mm³, respectively). Taliglucerase alfa was well-tolerated for up to 33 months and demonstrated a durable therapeutic effect.

Improvement in bone marrow infiltration in patients with type I Gaucher disease treated with taliglucerase alfa

Preliminary data suggest a positive effect of taliglucerase alfa on the bone marrow infiltration of Gaucher cells. In this investigator-initiated study, we report the impact of taliglucerase alfa on the bone marrow fat fraction (FF) in 26 patients assessed by quantitative chemical shift imaging (QCSI). Of 15 treatment-naïve patients (median age 48 [range 24-68] years), eight had baseline FF ≤ 0.3, six of those with a FF ≤ 0.23 ('bone at risk'). All significantly improved from a median baseline FF of 0.24 (0.15-0.32) to 1st year FF of 0.37 (0.25-0.54) and 2nd year FF of 0.42 (0.27-0.59) (p = 0.01). Among the 11 'switch-over' patients (median age 42 [range 33-69] years; median imiglucerase exposure 8 [range 1-17] years), eight had baseline FF ≤ 0.3, five of those with FF < 0.23. All, but one, significantly improved from a median baseline FF of 0.17 (0.08-0.28) to 1st year FF of 0.3 (0.05-0.34) and 2nd year FF of 0.34 (0.08-0.44) (p = 0.03). Two elderly female patients (age 43 and 58 years, with 17 years imiglucerase exposure) who remained at the same enzyme replacement therapy dose, increased from baseline FF of 0.13 and 0.19 to 0.26 at 1 year. Although the number of observations is small, we hypothesize that switching to taliglucerase may result in an improved bone marrow response. A larger study is needed to assess the early benefit of taliglucerase alfa in adult patients with type 1 Gaucher disease on the bone marrow compartment.

Taliglucerase alfa: safety and efficacy across 6 clinical studies in adults and children with Gaucher disease

Taliglucerase alfa is an enzyme replacement therapy (ERT) approved for treatment of adult and paediatric patients with Type 1 Gaucher disease (GD) in several countries and the first plant cell-expressed recombinant therapeutic protein approved by the US Food and Drug Administration for humans. Here, we review the findings across six key taliglucerase alfa clinical studies. A total of 33 treatment-naïve adult patients were randomized to taliglucerase alfa 30 U/kg or 60 U/kg in a 9-month, multicentre, randomized, double-blind, parallel-group, dose-comparison pivotal study, after which eligible patients continued into two consecutive extension studies; 17 treatment-naïve adult patients completed 5 total years of treatment with taliglucerase alfa. In the only ERT study focused on exclusively paediatric patients with GD, 11 treatment-naïve children were randomized to taliglucerase alfa 30 U/kg or 60 U/kg in a 12-month, multicentre, double-blind study; nine completed 3 total years of treatment in a dedicated paediatric extension study. The effect of switching patients from imiglucerase to taliglucerase alfa was also investigated in a separate 9-month study that included 26 adults and five children; 10 adults completed a total of 3 years and two children completed a total of 2.75 years of taliglucerase alfa treatment in the extension studies. All studies evaluated safety and spleen volume, liver volume, platelet count, haemoglobin concentration, and biomarkers as measures of efficacy. Detailed results from baseline through the end of these studies are presented. Taliglucerase alfa was well tolerated, and adverse events were generally mild/moderate in severity and transient. Treatment with taliglucerase alfa resulted in improvements (treatment-naïve patients) or stability (patients switched from imiglucerase) in visceral, haematologic, and biomarker parameters. Together, this comprehensive data set supports the treatment of adult and paediatric patients with GD who are naïve to ERT or who have previously been treated with imiglucerase.

Immunogenicity of glycans on biotherapeutic drugs produced in plant expression systems-The taliglucerase alfa story

Plants are a promising alternative for the production of biotherapeutics. Manufacturing in-planta adds plant specific glycans. To understand immunogenic potential of these glycans, we developed a validated method to detect plant specific glycan antibodies in human serum. Using this assay, low prevalence of pre-existing anti-plant glycan antibodies was found in healthy humans (13.5%) and in glucocerebrosidase-deficient Gaucher disease (GD) patients (5%). A low incidence (9% in naïve patient and none in treatment experienced patients) of induced anti-plant glycan antibodies was observed in GD patients after up to 30 months replacement therapy treatment with taliglucerase alfa, a version of human glucocerebrosidase produced in plant cells. Detailed evaluation of clinical safety and efficacy endpoints indicated that anti-plant glycan antibodies did not affect the safety or efficacy of taliglucerase alfa in patients. This study shows the benefit of using large scale human trials to evaluate the immunogenicity risk of plant derived glycans, and indicates no apparent risk related to anti-plant glycan antibodies.

The use of port-a-caths in adult patients with Lysosomal Storage Disorders receiving Enzyme Replacement Therapy-one centre experience

Port-a-cath is a widely used device in patients with long-term venous access demand such as frequent or continuous administration of medications such as Enzyme Replacement Therapy (ERT), chemotherapy delivery, blood transfusions, blood products, and fluids. Patients with Lysosomal Storage Diseases (LSDs) often require recurrent courses of ERT. We reviewed our experience of using port-a-caths in patients with LSDs with the focus on challenges and complications associated with these catheters. Among 245 adult patients who were treated with ERT, twenty patients (8.2%) had a port-a-cath inserted due to poor venous access. Six patients were using their first port whereas five other patients had their port-a-caths replaced at least once. The remaining six patients had inactive port-a-caths. The majority of patients with active port-a-caths never missed more than one consecutive infusion, although one patient missed 2 consecutive infusions whilst on holiday. We identified significant gaps in patients' and their families' understanding of the management of port-a-caths and risks associated with them. It resulted in producing a leaflet and designing an educational program for our LSD patients.

Spotlight on taliglucerase alfa in the treatment of pediatric patients with type 1 Gaucher disease

Gaucher disease (GD) is a heritable storage disorder caused by functional defects of the lysosomal acid β-glucosidase and the accumulation of glucosylceramide within macrophages, resulting in multiple organ dysfunction. There are three commercially available enzyme replacement therapy (ERT) products for the treatment of GD type 1 (GD1): imiglucerase, velaglucerase alfa, and taliglucerase alfa. Imiglucerase and velaglucerase alfa are produced in different mammalian cell systems; imiglucerase requires postproduction deglycosylation to expose terminal α-mannose residues, which are required for mannose receptor-mediated uptake by target macrophages. These steps are critical to the success of ERT for the treatment of visceral and hematologic manifestations of GD. Taliglucerase alfa is the first US Food and Drug Administration-approved plant-cell-expressed recombinant human protein, using carrot root cell cultures. Furthermore, it does not require postproduction glycosidic modifications. It is indicated for treatment of adults with GD1 in the US, Israel, Australia, Canada, Chile, Brazil, and other countries, and it is additionally approved for the treatment of pediatric patients in the US, Australia, and Canada and for the treatment of hematologic manifestations in pediatric patients with Type 3 GD in Canada and other countries. Our review focuses on the role of taliglucerase alfa in the pediatric population. A literature search through PubMed (from 1995 up till November 2016) of English language articles was performed with the following terms: Gaucher disease, lysosomal storage disease, taliglucerase. Secondary and tertiary references were obtained by reviewing related articles as well as the website www.Clinicaltrials.gov. It has been demonstrated that taliglucerase alfa is efficacious, with a well-established safety profile in pediatric, ERT-naïve patients with symptomatic GD1, as well as for those patients previously treated with imiglucerase.

A Perspective on the Development of Plant-Made Vaccines in the Fight against Ebola Virus

The Ebola virus (EBOV) epidemic indicated a great need for prophylactic and therapeutic strategies. The use of plants for the production of biopharmaceuticals is a concept being adopted by the pharmaceutical industry, with an enzyme for human use currently commercialized since 2012 and some plant-based vaccines close to being commercialized. Although plant-based antibodies against EBOV are under clinical evaluation, the development of plant-based vaccines against EBOV essentially remains an unexplored area. The current technologies for the production of plant-based vaccines include stable nuclear expression, transient expression mediated by viral vectors, and chloroplast expression. Specific perspectives on how these technologies can be applied for developing anti-EBOV vaccines are provided, including possibilities for the design of immunogens as well as the potential of the distinct expression modalities to produce the most relevant EBOV antigens in plants considering yields, posttranslational modifications, production time, and downstream processing.

Expression and functional evaluation of biopharmaceuticals made in plant chloroplasts

After approval of the first plant-made biopharmaceutical by FDA for human use, many protein drugs are now in clinical development. Within the last decade, significant advances have been made in expression of heterologous complex/large proteins in chloroplasts of edible plants using codon optimized human or viral genes. Furthermore, advances in quantification enable determination of in-planta drug dosage. Oral delivery of plastid-made biopharmaceuticals (PMB) is affordable because it eliminates prohibitively expensive fermentation, purification processes addressing major challenges of short shelf-life after cold storage. In this review, we discuss recent advances in PMBs against metabolic, inherited or infectious diseases, and also mechanisms of post-translational modifications (PTM) in order to increase our understanding of functional PMBs.

Taliglucerase alfa in Gaucher disease: Description of a Brazilian experience

We evaluated retrospectively, efficacy and safety of taliglucerase alfa for Gaucher disease in a Brazilian population. Thirteen patients were included for efficacy analysis only one of them naïve to enzyme replacement therapy. All the parameters evaluated remained stable throughout treatment (mean duration 3,5years). Only three patients (out of 35) had to discontinue treatment due to a serious adverse event. In conclusion, treatment with taliglucerase alfa was found to be safe and efficient.

Stability is maintained in adults with Gaucher disease type 1 switched from velaglucerase alfa to eliglustat or imiglucerase: A sub-analysis of the eliglustat ENCORE trial

Gaucher disease type 1 is an autosomal recessive disorder caused by deficient activity of the lysosomal enzyme acid β-glucosidase resulting in accumulation of glucosylceramide and clinical manifestations of anemia, thrombocytopenia, hepatosplenomegaly, and skeletal disease. The historic standard of care is intravenous recombinant enzyme therapy with imiglucerase. Eliglustat, an oral substrate reduction therapy, is a first-line treatment for adults with Gaucher disease type 1 who have a compatible CYP2D6-metabolizer phenotype (≈ 95% of patients). The 12-month ENCORE trial (NCT00943111) found eliglustat non-inferior to imiglucerase in maintaining stability in adult Gaucher patients previously stabilized after ≥ 3 years of enzyme therapy (imiglucerase or velaglucerase alfa). This post-hoc analysis examined safety and efficacy in the 30 ENCORE patients who were receiving velaglucerase alfa at study entry and were randomized to eliglustat (n = 22) or imiglucerase (n = 8). Efficacy and safety in velaglucerase alfa-transitioned patients were consistent with the full ENCORE trial population; 90% of patients switched to eliglustat and 88% of patients switched to imiglucerase met the composite endpoint (stable hemoglobin concentration, platelet count, spleen volume, and liver volume). Clinical stability was maintained for 12 months in Gaucher disease type 1 patients in the ENCORE trial who switched from velaglucerase alfa to either eliglustat or imiglucerase.

Enzyme Replacement or Substrate Reduction? A Review of Gaucher Disease Treatment Options

BACKGROUND

Gaucher disease is a rare lysosomal storage disease resulting from a deficiency or reduced activity in the acid β-glucocosidase enzyme. Only 1 treatment option was available for 15 years, but several new treatment options have come to market since 2003.

OBJECTIVE

The article will detail the pathophysiology and review current therapies in the literature for all 3 major clinical types of Gaucher disease, with a focus on considerations for selecting therapy in type 1 disease.

METHODS

Extracted and summarized applicable studies and reviews from Cochrane Review, ClinicalTrials.gov, CINAHL, IPA, and PubMed.

RESULTS

Enzyme replacement therapy is preferred for the management of Gaucher disease. Current literature does not favor any enzyme replacement product over another. However, velaglucerase alfa and taliglucerase alfa theoretically have a lower risk of immunogenicity reactions compared with imiglucerase. Alternative treatments for type 1 disease include substrate reduction therapy; however, these treatments require evaluation of patient-specific variables (eg, genotype evaluation, renal function) and consideration of adverse effect and dosing profiles. Evaluation of current literature found no substrate reduction therapy is preferred over another. There are no approved therapies for type 2 and type 3 disease, but enzyme replacement therapy may be used with limited efficacy for symptom management.

CONCLUSION

Enzyme replacement therapy is preferred for treating type 1 Gaucher disease and substrate replacement therapy may be considered in patients who do not tolerate or cannot receive enzyme replacement therapy.

Enzyme replacement therapy with taliglucerase alfa: 36-month safety and efficacy results in adult patients with Gaucher disease previously treated with imiglucerase

Taliglucerase alfa is the first available plant cell‐expressed human recombinant therapeutic protein. It is indicated for treatment of patients with type 1 Gaucher disease (GD) in adult and pediatric patients in several countries. Study PB‐06‐002 examined the safety and efficacy of taliglucerase alfa for 9 months in patients who previously received imiglucerase. The results of adult patients from Study PB‐06‐002 who continued receiving taliglucerase alfa in extension Study PB‐06‐003 for up to 36 months are reported here. Eighteen patients received at least one dose of taliglucerase alfa in Study PB‐06‐003; 10 patients completed 36 total months of therapy, and four patients who transitioned to commercial drug completed 30–33 months of treatment. In patients who completed 36 total months of treatment, mean percent (±standard error) changes from baseline/time of switch to taliglucerase alfa to 36 months were as follows: hemoglobin concentration, −1.0% (±1.9%; n = 10); platelet count, +9.3% (±9.8%; n = 10); spleen volume measured in multiples of normal (MN), −19.8% (±9.9%; n = 7); liver volume measured in MN, +0.9% (±5.4%; n = 8); chitotriosidase activity, −51.5% (±8.1%; n = 10); and CCL18 concentration, −36.5 (±8.0%; n = 10). Four patients developed antidrug antibodies, including one with evidence of neutralizing activity in vitro. All treatment‐related adverse events were mild or moderate and transient. The 36‐month results of switching from imiglucerase to taliglucerase alfa treatment in adults with GD provide further data on the clinical safety and efficacy of taliglucerase alfa beyond the initial 9 months of the original study. www.clinicaltrials.gov identifier NCT00705939. Am. J. Hematol. 91:661–665, 2016. © 2016 Wiley Periodicals, Inc.

Processing of complex N-glycans in IgG Fc-region is affected by core fucosylation

We investigated N-glycan processing of immunoglobulin G1 using the monoclonal antibody cetuximab (CxMab), which has a glycosite in the Fab domain in addition to the conserved Fc glycosylation, as a reporter. Three GlcNAc (Gn) terminating bi-antennary glycoforms of CxMab differing in core fucosylation (α1,3- and α1,6-linkage) were generated in a plant-based expression platform. These GnGn, GnGnF(3), and GnGnF(6) CxMab variants were subjected in vivo to further processing toward sialylation and GlcNAc diversification (bisected and branching structures). Mass spectrometry-based glycan analyses revealed efficient processing of Fab glycans toward envisaged structures. By contrast, Fc glycan processing largely depend on the presence of core fucose. A particularly strong support of glycan processing in the presence of plant-specific core α1,3-fucose was observed. Consistently, molecular modeling suggests changes in the interactions of the Fc carbohydrate chain depending on the presence of core fucose, possibly changing the accessibility. Here, we provide data that reveal molecular mechanisms of glycan processing of IgG antibodies, which may have implications for the generation of glycan-engineered therapeutic antibodies with improved efficacies.

Current Developments and Future Prospects for Plant-Made Biopharmaceuticals Against Rabies

Rabies is a prevalent health problem in developing countries. Although vaccines and immunoglobulin treatments are available, their cost and multiple-dose treatments restrict availability. During the last two decades, plants have served as a low-cost platform for biopharmaceuticals production and have been applied to fight against rabies during the last two decades. Herein, I provide a description of the state of the art in the development of plant-made pharmaceuticals against rabies and identify key prospects for the field in terms of novel strategies, immunogen design, and therapeutic antibodies production.

Procedure to Evaluate the Efficiency of Flocculants for the Removal of Dispersed Particles from Plant Extracts

Plants are important to humans not only because they provide commodities such as food, feed and raw materials, but increasingly because they can be used as manufacturing platforms for added-value products such as biopharmaceuticals. In both cases, liquid plant extracts may need to be clarified to remove particulates. Optimal clarification reduces the costs of filtration and centrifugation by increasing capacity and longevity. This can be achieved by introducing charged polymers known as flocculants, which cross-link dispersed particles to facilitate solid-liquid separation. There are no mechanistic flocculation models for complex mixtures such as plant extracts so empirical models are used instead. Here a design-of-experiments procedure is described that allows the rapid screening of different flocculants, optimizing the clarification of plant extracts and significantly reducing turbidity. The resulting predictive models allow the identification of robust process conditions and sets of polymers with complementary properties, e.g. effective flocculation in extracts with specific conductivities. The results presented for tobacco leaf extracts can easily be adapted to other plant species or tissues and will thus facilitate the development of more cost-effective downstream processes for commodities and plant-derived pharmaceuticals.

Profile of eliglustat tartrate in the management of Gaucher disease

Gaucher disease (GD) is a lysosomal storage disorder caused by the deficient activity of acid beta glucosidase, with consequent accumulation of glucosylceramide in the spleen, liver, bone marrow, and various organs and tissues. Currently, the gold standard for GD treatment is enzyme replacement therapy (ERT). The efficacy of ERT in improving or stabilizing the visceral and hematological symptoms of GD is well-proven. However, since ERT has to be administered by frequent intravenous infusions, this therapeutic approach has an important impact on the patient’s quality of life. Eliglustat tartrate is a new substrate reduction therapy for GD, which acts as a specific and potent inhibitor of glucosylceramide synthase and can be administered orally. This review summarizes the results of the preclinical and clinical trials, which experimented with eliglustat, and discusses its possible role in the management of GD, when compared to the currently available treatments and the new experimental approaches.

Optimized Blanching Reduces the Host Cell Protein Content and Substantially Enhances the Recovery and Stability of Two Plant-Derived Malaria Vaccine Candidates

Plants provide an advantageous expression platform for biopharmaceutical proteins because of their low pathogen burden and potential for inexpensive, large-scale production. However, the purification of target proteins can be challenging due to issues with extraction, the removal of host cell proteins (HCPs), and low expression levels. The heat treatment of crude extracts can reduce the quantity of HCPs by precipitation thus increasing the purity of the target protein and streamlining downstream purification. In the overall context of downstream process (DSP) development for plant-derived malaria vaccine candidates, we applied a design-of-experiments approach to enhance HCP precipitation from Nicotiana benthamiana extracts generated after transient expression, using temperatures in the 20-80°C range, pH values of 3.0-8.0 and incubation times of 0-60 min. We also investigated the recovery of two protein-based malaria vaccine candidates under these conditions and determined their stability in the heat-treated extract while it was maintained at room temperature for 24 h. The heat precipitation of HCPs was also carried out by blanching intact plants in water or buffer prior to extraction in a blender. Our data show that all the heat precipitation methods reduced the amount of HCP in the crude plant extracts by more than 80%, simplifying the subsequent DSP steps. Furthermore, when the heat treatment was performed at 80°C rather than 65°C, both malaria vaccine candidates were more stable after extraction and the recovery of both proteins increased by more than 30%.

N-Glycosylation of Cholera Toxin B Subunit: Serendipity for Novel Plant-Made Vaccines?

The non-toxic B subunit of cholera toxin (CTB) has attracted considerable interests from vaccinologists due to strong mucosal immunomodulatory effects and potential utility as a vaccine scaffold for heterologous antigens. Along with other conventional protein expression systems, various plant species have been used as production hosts for CTB and its fusion proteins. However, it has recently become clear that the protein is N-glycosylated within the endoplasmic reticulum of plant cells-a eukaryotic post-translational modification that is not present in native CTB. While functionally active aglycosylated variants have been successfully engineered to circumvent potential safety and regulatory issues related to glycosylation, this modification may actually provide advantageous characteristics to the protein as a vaccine platform. Based on data from our recent studies, I discuss the unique features of N-glycosylated CTB produced in plants for the development of novel vaccines.

Commercial-scale biotherapeutics manufacturing facility for plant-made pharmaceuticals

Rapid, large-scale manufacture of medical countermeasures can be uniquely met by the plant-made-pharmaceutical platform technology. As a participant in the Defense Advanced Research Projects Agency (DARPA) Blue Angel project, the Caliber Biotherapeutics facility was designed, constructed, commissioned and released a therapeutic target (H1N1 influenza subunit vaccine) in <18 months from groundbreaking. As of 2015, this facility was one of the world's largest plant-based manufacturing facilities, with the capacity to process over 3500 kg of plant biomass per week in an automated multilevel growing environment using proprietary LED lighting. The facility can commission additional plant grow rooms that are already built to double this capacity. In addition to the commercial-scale manufacturing facility, a pilot production facility was designed based on the large-scale manufacturing specifications as a way to integrate product development and technology transfer. The primary research, development and manufacturing system employs vacuum-infiltrated Nicotiana benthamiana plants grown in a fully contained, hydroponic system for transient expression of recombinant proteins. This expression platform has been linked to a downstream process system, analytical characterization, and assessment of biological activity. This integrated approach has demonstrated rapid, high-quality production of therapeutic monoclonal antibody targets, including a panel of rituximab biosimilar/biobetter molecules and antiviral antibodies against influenza and dengue fever.

13,845 home therapy infusions with velaglucerase alfa exemplify safety of velaglucerase alfa and increased compliance to every-other-week intravenous enzyme replacement therapy for Gaucher disease

BACKGROUND

Lifelong intravenous (IV) enzyme replacement therapy (ERT) every other week for Gaucher disease is appreciated as decreasing quality of life in a palpable way.

OBJECTIVE

To review the Israeli experience with the home therapy option for IV velaglucerase alfa (Shire, Lexington MA USA) infusions every-other-week in the clinical trial context, in the early access program (EAP) during a shortage with the standard commercial ERT, and currently with the commercially available drug (VPRIV, Shire).

RESULTS

Among 24 patients participating in trials, 1654 infusions were at home; in the EAP and commercial setting, 12,191 infusions were performed at home for a total of 154 patients with 98.4% compliance. There were no incidents of serious adverse events.

CONCLUSION

This is the first review of experience of 174 patients and 13,845 intravenous infusions of velaglucerase alfa for Gaucher in the home setting, underscoring its safety.

Pharmacokinetics of Novel Plant Cell-Expressed Taliglucerase Alfa in Adult and Pediatric Patients with Gaucher Disease

Taliglucerase alfa is a beta-glucocerebrosidase enzyme replacement therapy approved in the United States, Israel, and other countries for treatment of Type 1 Gaucher disease in adults, and is the first approved plant cell--expressed recombinant protein. In this report, taliglucerase alfa pharmacokinetics were assessed in adult and pediatric patients with Gaucher disease from separate multicenter trials of 30 Units/kg and 60 Units/kg doses infused every 2 weeks. Serial blood samples were obtained from adult patients following single-dose administration on day 1 (n = 26) and multiple doses at week 38 (n = 29), and from pediatric patients following administration of multiple doses of taliglucerase alfa for 10-27 months (n = 10). In both adult and pediatric patients, maximum plasma concentration (Cmax), area under the plasma concentration-time curve from time zero to last measureable concentration (AUC0-t), and from time zero to infinity (AUC0-∞) were higher after 60 Units/kg dose than 30 Units/kg dose. No tendency for accumulation or change in taliglucerase alfa pharmacokinetic parameters over time from day 1 to week 38 was observed with repeated doses of 30 or 60 Units/kg in adults. After multiple doses, mean (range) dose-normalized pharmacokinetic parameters were similar for adult versus pediatric patients receiving 60 Units/kg: Cmax expressed in ng/mL/mg was 42.4 (14.5-95.4) in adults and 46.6 (34.4-68.4) in pediatric patients, AUC0 t expressed in ng • h/mL/mg was 63.4 (26.3-156) in adults and 63.9 (39.8-85.1) in pediatric patients, t1/2 expressed in minutes was 34.8 (11.3-104) in adults and 31.5 (18.0-42.9) in pediatric patients and total body clearance expressed in L/h was 19.9 (6.25-37.9) in adults and 17.0 (11.7-24.9) in pediatric patients. These pharmacokinetic data extend the findings of taliglucerase alfa in adult and pediatric patients.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT00376168 (in adults); NCT01411228 (in children).

Extraction and downstream processing of plant-derived recombinant proteins

Plants offer the tantalizing prospect of low-cost automated manufacturing processes for biopharmaceutical proteins, but several challenges must be addressed before such goals are realized and the most significant hurdles are found during downstream processing (DSP). In contrast to the standardized microbial and mammalian cell platforms embraced by the biopharmaceutical industry, there are many different plant-based expression systems vying for attention, and those with the greatest potential to provide inexpensive biopharmaceuticals are also the ones with the most significant drawbacks in terms of DSP. This is because the most scalable plant systems are based on the expression of intracellular proteins in whole plants. The plant tissue must therefore be disrupted to extract the product, challenging the initial DSP steps with an unusually high load of both particulate and soluble contaminants. DSP platform technologies can accelerate and simplify process development, including centrifugation, filtration, flocculation, and integrated methods that combine solid-liquid separation, purification and concentration, such as aqueous two-phase separation systems. Protein tags can also facilitate these DSP steps, but they are difficult to transfer to a commercial environment and more generic, flexible and scalable strategies to separate target and host cell proteins are preferable, such as membrane technologies and heat/pH precipitation. In this context, clarified plant extracts behave similarly to the feed stream from microbes or mammalian cells and the corresponding purification methods can be applied, as long as they are adapted for plant-specific soluble contaminants such as the superabundant protein RuBisCO. Plant-derived pharmaceutical proteins cannot yet compete directly with established platforms but they are beginning to penetrate niche markets that allow the beneficial properties of plants to be exploited, such as the ability to produce 'biobetters' with tailored glycans, the ability to scale up production rapidly for emergency responses and the ability to produce commodity recombinant proteins on an agricultural scale.

The increasing value of plant-made proteins

The production of high-value proteins in plants is maturing, as shown by the recent approval of innovative products and the latest studies that showcase plant-based production systems using technologies and approaches that are well established in other fields. These include host cell engineering, medium optimization, scalable unit operations for downstream processing (DSP), bioprocess optimization and detailed cost analysis. Product-specific benefits of plant-based systems have also been exploited, including bioencapsulation and the mucosal delivery of minimally processed topical and oral products with a lower entry barrier than pharmaceuticals for injection. Success stories spearheaded by the FDA approval of Elelyso developed by Protalix have revitalized the field and further interest has been fueled by the production of experimental Ebola treatments in plants.