Overview of recombinant human hyaluronidase-facilitated subcutaneous infusion of IgG in primary immunodeficiencies

Facial cosmetic injection: A bibliometric analysis of research status and hotspots

BACKGROUND

The increasing popularity of cosmetic injections using various fillers and neuromodulators for facial rejuvenation has brought both new opportunities and challenges to this field.

AIM

Our study was designed to employ bibliometric and visual analysis for a qualitative and quantitative evaluation of facial cosmetic injections, as well as to identify research trends and hotspots in this field.

METHODS

All publications covering facial cosmetic injection during 2002-2023 were retrieved and extracted from the Web of Science database. The VOSviewer 1.6.18 software and the online tool (http://bibliometric.com/) were applied to analyze the publication trend.

RESULTS

A total of 3797 articles related to facial cosmetic injection were identified during the period 2002-2023. The United States had the largest volume of publications (1520, 40.0%), followed by China (333, 8.8%) and Germany (282, 7.3%). Among the institutions and journals, the University of California system and Plastic and Reconstructive Surgery accounted for the most papers related to facial cosmetic injection, respectively. Facial anatomy and injection techniques, prevention and management of complications, regenerative medicine, efficacy and safety of various soft-tissue fillers, as well as botulinum toxin injections for facial rejuvenation were identified as hotspots for facial cosmetic injections.

CONCLUSIONS

Facial cosmetic injections are showing an increasing trend in terms of both the number of published papers and operations performed. Despite the notable advancements in this field, numerous challenges persist, including safety concerns and the level of research evidence. With the emergence of novel technologies and materials, scholars from diverse countries and institutions should engage in more extensive collaboration, thereby directly expediting the progress of this field.

Predicting the clinical subcutaneous absorption rate constant of monoclonal antibodies using only the primary sequence: a machine learning approach

Subcutaneous injections are an increasingly prevalent route of administration for delivering biological therapies including monoclonal antibodies (mAbs). Compared with intravenous delivery, subcutaneous injections reduce administration costs, shorten the administration time, and are strongly preferred from a patient experience point of view. An understanding of the absorption process of a mAb from the injection site to the systemic circulation is critical to the process of subcutaneous mAb formulation development. In this study, we built a model to predict the absorption rate constant (ka), which denotes how fast a mAb is absorbed from the site of administration. Once trained, our model (enabled by the XGBoost algorithm in machine learning) can predict the ka of a mAb following a subcutaneous injection using in silico molecular properties alone (generated from the primary sequence). Our model does not need clinically observed plasma concentration-time data; this is a novel capability not previously achieved in predictive pharmacokinetic models. The model also showed improved performance when benchmarked against a recently reported mechanistic model that relied on clinical data to predict subcutaneous absorption of mAbs. We further interpreted the model to understand which molecular properties affect the absorption rate and showed that our findings are consistent with previous studies evaluating subcutaneous absorption through direct experimentation. Taken altogether, this study reports the development, validation, benchmarking, and interpretation of a model that can predict the clinical ka of a mAb using its primary sequence as the only input.

Identifying a predictive relationship between maximal flow rate and viscosity for subcutaneous administration of macromolecules with recombinant human hyaluronidase PH20 in a miniature pig model

Subcutaneous (SC) infusion of large volumes at rapid flow rates has historically been limited by the glycosaminoglycan hyaluronan (HA), which forms a barrier to bulk fluid flow in the SC space. Recombinant human hyaluronidase PH20 (rHuPH20) depolymerizes HA, temporarily eliminating this barrier to rapid SC delivery of large volume co-administered therapeutics. Using a miniature pig model, in-line pressure and applied force to the delivery hardware were measured when subcutaneously infusing a representative macromolecule (human polyclonal immunoglobulin [Ig]), at varying concentrations and viscosities (20-200 mg/mL), co-formulated with and without rHuPH20 (2000 U/mL and 5000 U/mL). Maximal flow rate (Qmax) was calculated as the flow rate producing a statistically significant difference in mean applied force between injections administered with or without rHuPH20. There was a significant reduction in mean applied force required for SC delivery of 100 mg/mL Ig solution with 5000 U/mL rHuPH20 versus Ig solution alone. Similar significant reductions in mean applied force were observed for most Ig solution concentrations, ranging from 25-200 mg/mL when administered with or without 2000 U/mL rHuPH20. Qmax was inversely proportional to Ig solution viscosity and Qmax for solutions co-formulated with 5000 U/mL rHuPH20 was approximately double that of 2000 U/mL rHuPH20 solutions. Mathematical simulation of a hypothetical 800 mg Ig dose co-formulated with rHuPH20 showed that delivery times <30 s could be achieved across a broad range of concentrations. Addition of rHuPH20 can help overcome volume and time constraints associated with SC administration across a range of concentrations in a dose-dependent manner.

Management of humoral secondary immunodeficiency in hematological malignancies and following hematopoietic stem cell transplantation: Regional perspectives

Secondary immunodeficiency (SID) can occur as a result of multiple factors, including hematological malignancies, hematopoietic stem cell transplantation (HSCT), immunosuppressive treatment, biologics, and anti-inflammatory drugs. SID includes disorders resulting from impairment of both cellular and humoral immunity. This review focuses on the current risk factors, implications, and challenges in managing SID patients with impaired humoral immunity, which includes quantitative (hypogammaglobulinemia) and/or functional antibody and B-cell deficiencies specifically related to hematological malignancies and post-HSCT. Increased physician awareness is needed surrounding the disease presentation and early risk factors, as SID may be caused by several etiologies. Careful clinical assessment is then required to optimize management, which encompasses close monitoring of clinical parameters, vaccination, antibiotic prophylaxis, and immunoglobulin replacement therapy (IGRT). Novel methods of IGRT administration are associated with enhanced pharmacokinetics, IgG trough level stability, no need for venous access, as well as fewer systemic adverse events and better administration flexibility compared with traditional methods. Published international guidelines supported by observations from clinical data are broadly followed; however, best practices within each country have nuances that underline the need to tailor treatment plans to the individual patient.

Effectiveness of retrobulbar hyaluronidase in the treatment of visual loss caused by periocular hyaluronic acid injection. A systematic review

INTRODUCTION

Blindness after periocular cosmetic filler injection is a rare but devastating complication. Complication management protocols recommend injecting retrobulbar hyaluronidase if visual loss related to accidental intravascular injection of hyaluronic acid occurs. Given the dramatic increase in cosmetic filler injections and the variety of professionals that can deliver them, it is reasonable to assume that the incidence of complications will rise significantly.

OBJECTIVE

To evaluate if there is evidence-based efficacy of retrobulbar hyaluronidase injection in visual loss secondary to periocular cosmetic filler injection.

MATERIAL AND METHODS

The authors performed a search of English and Spanish language articles following the PRISMA statement published on the use of retrobulbar hyaluronidase to reverse vision loss precipitated by hyaluronic acid gel fillers. Articles reviewed included case reports/series and experimental investigations. We identified a total of 13 patients in this review following defined inclusion and exclusion criteria. Finally, we included 15 articles in the study, 12 of them were cases / case series. The 2 remaining articles are experimental studies in animals with a control group, in which after causing selective occlusion of the ophthalmic artery, serial injections of retroocular hyaluronidase are administered with control of visual function.

RESULTS

Of the 15 articles included in the study, we studied 17 patients treated with retrobulbar hyaluronidase for hyaluronic acid-induced blindness. Improvement was demonstrated in 3 cases. Animal studies demonstrate variable data are provided regarding the recovery of visual acuity.

CONCLUSIONS

There is no confirmed evidence of retrobulbar hyaluronidase injection effectiveness in treating visual loss due to accidental intravascular injection of hyaluronic acid. More studies are needed to show the efficacy of hyaluronidase as a treatment for blindness caused by hyaluronic acid.

Cost-minimization analysis of immunoglobulin treatment of primary immunodeficiency diseases in Spain

Primary immunodeficiency diseases (PID), which are comprised of over 400 genetic disorders, occur when a component of the immune system is diminished or dysfunctional. Patients with PID who require immunoglobulin (IG) replacement therapy receive intravenous IG (IVIG) or subcutaneous IG (SCIG), each of which provides equivalent efficacy. We developed a cost-minimization model to evaluate costs of IVIG versus SCIG from the Spanish National Healthcare System perspective. The base case modeled the annual cost per patient of IVIG and SCIG for the mean doses (per current expert clinical practice) over 1 year in terms of direct (drug and administration) and indirect (lost productivity for adults and parents/guardians of pediatric patients) costs. It was assumed that all IVIG infusions were administered in a day hospital, and 95% of SCIG infusions were administered at home. Drug costs were calculated from ex-factory prices obtained from local databases minus the mandatory deduction. Costs were valued on 2018 euros. The annual modeled costs were €4,266 lower for patients with PID who received SCIG (total €14,466) compared with those who received IVIG (total €18,732). The two largest contributors were differences in annual IG costs as a function of dosage (- €1,927) and hospital administration costs (- €2,688). However, SCIG incurred training costs for home administration (€695). Sensitivity analyses for two dose-rounding scenarios were consistent with the base case. Our model suggests that SCIG may be a cost-saving alternative to IVIG for patients with PID in Spain.

Safety of recombinant human hyaluronidase PH20 for subcutaneous drug delivery

INTRODUCTION

The glycosaminoglycan hyaluronan forms a gel-like substance, which presents a barrier to bulk fluid flow in the subcutaneous (SC) space, limiting SC drug delivery volume and administration rates. Recombinant human hyaluronidase PH20 (rHuPH20) acts locally to temporarily remove this barrier, facilitating rapid SC delivery of large volumes and/or high doses of sequentially or co-administered therapeutics.

AREAS COVERED

An extensive clinical and post-marketing dataset of safety and immunogenicity of rHuPH20 in its current applications with approved therapeutics demonstrates that rHuPH20 acts locally, without measurable systemic absorption at the SC doses used in the approved products, and is well tolerated in combination with several co-administered therapeutic agents across diverse patient groups. The immunogenicity profile demonstrates no adverse effects associated with treatment-emergent rHuPH20 antibody responses. Immunogenicity to monoclonal antibodies co-formulated with rHuPH20 shows no clinical difference between SC and intravenous administration. Safety assessments of patient subsets for special populations, including children, elderly patients, and pregnant women, raise no additional safety concerns.

EXPERT OPINION

The benefits of SC administration for patients and healthcare systems often outweigh those of intravenous administration, driving future initiation of SC-only drug development programs. Injection devices allowing large-volume SC administration could be facilitated by incorporating co-formulated biologics containing rHuPH20.

Process analytical technology for on-line monitoring of quality attributes during single-use ultrafiltration/diafiltration

Process analytical technology (PAT) is a fast-growing field within bioprocessing that enables innovation in biological drug manufacturing. This study demonstrates novel PAT methods for monitoring multiple quality attributes simultaneously during the ultrafiltration and diafiltration (UF/DF) process operation, the final step of monoclonal antibody (mAb) purification. Size exclusion chromatography (SEC) methods were developed to measure excipients arginine, histidine, and high molecular weight (HMW) species using a liquid chromatography (LC) system with autosampler for both on-line and at-line PAT modes. The methods were applied in UF/DF studies for the comparison of single-use tangential flow filtration (TFF) cassettes to standard reusable cassettes to achieve very high concentration mAb drug substance (DS) in the order of 100-200 g/L. These case studies demonstrated that single-use TFF cassettes are a functionally equivalent, low-cost alternative to standard reusable cassettes, and that the on-line PAT measurement of purity and excipient concentration was comparable to orthogonal offline methods. These PAT applications using an on-line LC system equipped with onboard sample dilution can become a platform system for monitoring of multiple attributes over a wide dynamic range, a potentially valuable tool for biological drug development and manufacturing.

Examining the Role of Retrobulbar Hyaluronidase in Reversing Filler-Induced Blindness: A Systematic Review

PURPOSE

To provide a systematic review of the literature concerning retrobulbar hyaluronidase injections as a treatment for hyaluronic acid gel filler-induced blindness and evaluate the level of evidence for this proposed therapy.

METHODS

The authors performed a search of English language articles published on the use of retrobulbar hyaluronidase to reverse vision loss precipitated by hyaluronic acid gel fillers. Articles reviewed included case reports/series, experimental investigations, expert opinion commentaries, and major reviews. To date, there have been no case-control, cohort, or randomized control studies to evaluate this treatment. Five anecdotal descriptions of hyaluronic acid gel filler blindness treated specifically with retrobulbar hyaluronidase were identified, for a total of 9 patients. One hundred twelve articles in total on this treatment and related topics, including filler-induced blindness and alternative treatments, were identified and reviewed.

RESULTS

Of the 9 documented cases of patients treated with retrobulbar hyaluronidase for hyaluronic acid-induced blindness, visual improvement was demonstrated in 2 cases. The successes, however, are undermined by inconsistent pretreatment ophthalmic assessment and documentation. Animal studies demonstrate mixed results. Laboratory studies document the inability of hyaluronidase to cross the optic nerve sheath.

CONCLUSIONS

There is not currently enough evidence to support retrobulbar hyaluronidase as a treatment for filler-induced blindness. Additional studies are needed to further evaluate its efficacy and explore alternative treatments.

Endovascular Hyaluronidase Application Through Superselective Angiography to Rescue Blindness Caused by Hyaluronic Acid Injection

BACKGROUND

Blindness is a rare but catastrophic complication of facial hyaluronic acid (HA) injection. Although various means to rescue visual impairment have been employed, no consensus regarding effective treatment has yet been reached. We organized a multidisciplinary team to address this emergency situation by means of endovascular hyaluronidase application.

OBJECTIVES

The aim of this study was to investigate the direct delivery of hyaluronidase to ophthalmic artery occlusion through endovascular cannulation to resolve HA-induced blindness.

METHODS

Four patients with visual impairments caused by HA filler embolization were subjected to sequential treatments. Through superselective angiography, a microcatheter was introduced along a guidewire from the femoral artery to the ophthalmic artery to directly deliver hyaluronidase to the HA embolism. The safety and efficiency of this treatment were systematically analyzed.

RESULTS

Selective cerebral angiography demonstrated that the endovascular application of hyaluronidase significantly alleviated occlusion in 3 patients. One patient showed slight visual improvement, whereas the other patients showed no improvement in their visual function during a follow-up period of more than 3 months. One patient suffered from cerebral infarction in the left middle cerebral artery during the intervention surgery. Moreover, 2 patients showed multiple lacunar cerebral infarctions after the operation, whereas none exhibited symptoms of hemiplegia during follow-up.

CONCLUSIONS

Although the endovascular application of hyaluronidase could partially recanalize the occluded branches of the ophthalmic artery, it had limited effects on restoring vision. Considering the risks of vascular intervention surgery, this approach should be considered with caution.

LEVEL OF EVIDENCE: 5

Clinical Evaluation of an Investigational 5 mL Wearable Injector in Healthy Human Subjects

An investigational wearable injector (WI), the BD Libertas Wearable Injector (BD Libertas is a trademark of Becton, Dickinson and Company), was evaluated in an early feasibility clinical study for functional performance, tissue effects, subject tolerability, and acceptability of 5 mL, non‐Newtonian ~ 8 cP subcutaneous placebo injections in 52 healthy adult subjects of 2 age groups (18–64 years and ≥ 65 years). Randomized WI subcutaneous injections (n = 208, 4/subject) were delivered to the right and left abdomen and thigh of each subject, 50% (1 thigh and 1 abdomen) with a defined movement sequence during injection. Injector functional performance was documented. Deposition was qualified and quantified with ultrasound. Tissue effects and tolerability (pain) were monitored through 24 hours with corresponding acceptability questionnaires administered through 72 hours. WI (n = 205) automatically inserted the needle, delivered 5 mL ± 5% in 5.42 minutes (SD 0.74) and retracted. Depots were entirely (93.2%) or predominantly (5.4%) localized within the target subcutaneous tissue. Slight to moderate wheals (63.9%) and erythema (75.1%) were observed with ≥ 50% resolution within 30–60 minutes. Subject pain (100 mm Visual Analog Scale) peaked mid‐injection (mean 9.1 mm, SD 13.4) and rapidly resolved within 30 minutes (mean 0.4 mm, SD 2.6). Subjects’ peak pain (≥ 90.2%), injection site appearance (≥ 92.2%) and injector wear, size, and removal (≥ 92.1%) were acceptable (Likert responses) with 100% likely to use the injector if prescribed. Injection site preference was divided between none (46%), abdomen (25%), or thigh (26.9%). The investigational WI successfully delivered 5 mL viscous subcutaneous injections. Tissue effects and pain were transient, well‐tolerated and acceptable. Neither injection site, movement or subject age affected injector functional performance or subject pain and acceptability.

Secondary immunodeficiencies with predominant antibody deficiency: multidisciplinary perspectives of Polish experts

At present, secondary immune deficiencies have become a clinical problem, recognized in different specialties. The aim of this paper was to increase awareness and support the need for screening at-risk populations. Secondary immune deficiencies result in variety of conditions, but not all of them require immunoglobulin replacement therapy, as specific antibody response might be preserved. Moreover, the management of secondary immune deficiencies vary between countries and different medical disciplines. This literature review presents the most common causes and clinical presentation of secondary immunodeficiencies with predominant impaired antibody production. We present diagnostic guidelines for patients at-risk, with an emphasis on the role of prophylactic vaccination as a treatment and diagnostic tool. This review considers the specificity and disparities of the Polish healthcare system and ultimately, suggests that management teams should include a clinical immunologist experienced in the treatment of humoral immunodeficiencies.

Hyaluronidase: An overview of its properties, applications, and side effects

Hyaluronidase, an enzyme that breaks down hyaluronic acid, has long been used to increase the absorption of drugs into tissue and to reduce tissue damage in cases of extravasation of a drug. With the increasing popularity of hyaluronic acid filler, hyaluronidase has become an essential drug for the correction of complications and unsatisfactory results after filler injection. For this reason, when performing procedures using hyaluronic acid filler, a sufficient knowledge of hyaluronidase is required. In order for hyaluronidase to dissolve a hyaluronic acid filler, it must interact with its binding sites within the hyaluronic acid. The reaction of a filler to hyaluronidase depends on the hyaluronic acid concentration, the number of crosslinks, and the form of the filler. Hyaluronidase is rapidly degraded and deactivated in the body. Therefore, in order to dissolve a hyaluronic acid filler, a sufficient amount of hyaluronidase must be injected close to the filler. If the filler is placed subcutaneously, injection of hyaluronidase into the filler itself may help, but if the filler is placed within a blood vessel, it is sufficient to inject hyaluronidase in the vicinity of the vessel, instead of into the filler itself. Allergic reactions are a common side effect of hyaluronidase. Most allergic reactions to hyaluronidase are local, but systemic reactions may occur in infrequent cases. Since most allergic responses to hyaluronidase are immediate hypersensitivity reactions, skin tests are recommended before use. However, some patients experience delayed allergic reactions, which skin tests may not predict.

Facilitated Subcutaneous Immunoglobulin Replacement Therapy in Clinical Practice: A Two Center, Long-Term Retrospective Observation in Adults With Primary Immunodeficiencies

Facilitated subcutaneous immunoglobulin (fSCIG) replacement therapy is the latest method of IgG administration; however, real-life data are limited. We retrospectively analyzed the everyday experience of fSCIG administration, particularly, the method used to switch from intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG) to fSCIG and the dosing modifications required. Of the 39 adult patients with primary immunodeficiency (PID) who received fSCIG, 34 remained on the therapy at the end of the study. The median observation time was 18 (range, 3–24) months. Two patients were IgG-treatment-naïve; 23 had previously received IVIG and 14 had received SCIG. In 25 cases, a non-ramp-up dosing mode was used to switch to fSCIG (including two half-monthly doses given biweekly in 14 cases, and full monthly doses given in 11 cases), a ramp-up mode was used in six cases; other methods were used in eight cases. The median IgG trough level at baseline was 7.9 g/L (n = 38), 7.9 g/L (n = 32) at Month 6, 9.0 g/L (n = 30) at Month 12, 8.6 g/L (n = 22) at Month 18, and 9.0 g/L (n = 11) at Month 24. No serious bacterial infections or hospitalizations due to PID complications occurred. At the end of the study, 24 patients (71%) received fSCIG every 4 weeks, six (18%) received fSCIG every 3 weeks, and four (12%) received fSCIG biweekly. In conclusion, our study provides real-life evidence of clinical efficacy of personalized fSCIG treatment when switching from prior immunoglobulin replacement using various switching modes and dosing frequencies.

Clinical Practice Experience with HyQvia in Adults Using Alternative Dosing Regimens and Pediatric Patients: A Retrospective Study

Introduction

HyQvia (Immune Globulin Infusion 10% [Human] with Recombinant Human Hyaluronidase) was developed to combine the advantages of intravenous and subcutaneous immune globulin (SCIG), allowing administration of larger volumes at a single subcutaneous site with less frequent dosing when compared to other SCIG products. Current US prescribing guidelines for HyQvia are limited to adults and do not encompass the flexibility required to achieve success in all patients with primary immunodeficiency (PID).

Methods

This retrospective study was designed to evaluate the clinical experience of treating patients with PID with HyQvia regimens outside of package insert recommendations as well as in pediatric patients. Data were abstracted from 38 patient records (317 HyQvia infusions), including five patients less than 16 years of age, from seven US immunology clinics.

Results

Among 37 patients receiving HyQvia regimens differing from prescribing guidelines, the most notable variations included shorter ramp-up periods, use of two rather than one infusion site, and slower than maximal infusion rates to mitigate local adverse events (AEs). The medication volume infused for single site doses ranged from 75 to 200 mL and doses split between two sites ranged from 100 to 750 mL. The most common type of regimen variation was a condensed ramp-up phase (shorter schedule, higher doses), and 96% (24/25) of patients managed in this way completed ramp-up. The most common ramp-up schedule was three infusions (one at 25–45%, another at 50–75%, and the final at 100% of target dose) spread over 2–4 weeks.

Conclusions

A shorter ramp-up schedule did not appear to increase the number of AEs compared to standard ramp-up schedules. For patients with AEs, slower infusion rates and the use of two sites may improve medication tolerability. Four of five pediatric patients reported no AEs, and only one discontinued, stating a fear of needles. HyQvia may be tailored to adults requiring alternative rates, ramp-up, and/or dosing regimens and may be especially well-suited to children.

Electronic supplementary material

The online version of this article (10.1007/s12325-020-01264-7) contains supplementary material, which is available to authorized users.

ENHANZE® drug delivery technology: a novel approach to subcutaneous administration using recombinant human hyaluronidase PH20

ENHANZE^® drug delivery technology is based on the proprietary recombinant human hyaluronidase PH20 enzyme (rHuPH20; Halozyme Therapeutics, Inc.) that facilitates the subcutaneous (SC) delivery of co‐administered therapeutics. rHuPH20 works by degrading the glycosaminoglycan hyaluronan (HA), which plays a role in resistance to bulk fluid flow in the SC space, limiting large volume SC drug delivery, dispersion, and absorption. Co-administration of rHuPH20 with partner therapies can overcome administration time and volume barriers associated with existing SC therapeutic formulations, and has been shown to reduce the burden on patients and healthcare providers compared with intravenous formulations. rHuPH20 (as HYLENEX^® recombinant) is currently FDA-approved for subcutaneous fluid administration for achieving hydration, to increase the dispersion and absorption of other injected drugs, and in subcutaneous urography for improving resorption of radiopaque agents. rHuPH20 is also co-formulated with two anticancer therapies, trastuzumab (i.e. Herceptin^® SC) and rituximab (i.e. RITUXAN HYCELA^®/RITUXAN^® SC/MabThera^® SC) and dosed sequentially with human immunoglobin to treat primary immunodeficiency (i.e. HyQvia^®/HYQVIA^®). This article reviews pharmaceutical properties of rHuPH20, its current applications with approved therapeutics, and the potential for future developments.

Mechanisms Influencing the Pharmacokinetics and Disposition of Monoclonal Antibodies and Peptides

Monoclonal antibodies (mAbs) and peptides are an important class of therapeutic modalities that have brought improved health outcomes in areas with limited therapeutic optionality. Presently, there more than 90 mAb and peptide therapeutics on the United States market, with over 600 more in various clinical stages of development in a broad array of therapeutic areas, including diabetes, autoimmune disorders, oncology, neuroscience, and cardiovascular and infectious diseases. Notwithstanding this potential, there is high clinical rate of attrition, with approximately 10% reaching patients. A major contributor to the failure of the molecules is often times an incomplete or poor understanding of the pharmacokinetics (PK) and disposition profiles leading to limited or diminished efficacy. Increased and thorough characterization efforts directed at disseminating mechanisms influencing the PK and disposition of mAbs and peptides can aid in improving the design for their intended pharmacological activity, and thereby their clinical success. The PK and disposition factors for mAbs and peptides are broadly influenced by target-mediated drug disposition and nontarget-related clearance mechanisms related to the interplay between the relationship of the structure and physiochemical properties of mAbs and peptides with physiologic processes. This review focuses on nontarget-related factors influencing the disposition and PK of mAbs and peptides. Contemporary considerations around the increasing in silico approaches to identify nontarget-related molecule limitations and enhancing the druggability of mAbs and peptides, including parenteral and nonparenteral delivery strategies that are geared toward improving patient experience and compliance, are also discussed.

Tolerability of subcutaneous immunoglobulin 20%, Ig20Gly, in pediatric patients with primary immunodeficiencies

AIM

To assess Ig20Gly tolerability in pediatric patients with primary immunodeficiencies.

PATIENTS & METHODS

Infusion parameters and tolerability were analyzed in pediatric patients (aged 2-5 years [n = 6], 6-11 years [n = 22] and 12-17 years [n = 22]) receiving Ig20Gly in two Phase II/III trials.

RESULTS

Of 2624 Ig20Gly infusions, >99% did not require any rate reduction, interruption or discontinuation due to adverse events (AEs). Median maximum infusion rates and volumes/site were higher in patients 12-17 years of age (30 ml/h/site; 30 ml/site) versus 6-11 years (20 ml/h/site; 15 ml/site) and 2-5 years (18 ml/h/site; 14 ml/site). Rates of causally related systemic and local AEs (0.009 and 0.063 AEs/infusion) were low.

CONCLUSION

Ig20Gly infused at relatively high rates and volumes was well tolerated in children.

Primary immunodeficiency diseases in lung disease: warning signs, diagnosis and management

Background

Pulmonary complications are common in primary immunodeficiency diseases (PID) and contribute to morbidity and mortality in these patients. However, their varied presentation and a general lack of awareness of PID in this setting make early diagnosis and treatment difficult. The aim of this study was to define the warning signs of PID in patients with respiratory manifestations, the necessary diagnostic tests, and the therapeutic management of both children and adults.

Methods

A review of the literature was performed, and 43 PID interdisciplinary specialists were consulted.

Results

This document identifies the pulmonary and extrapulmonary manifestations that should prompt a suspicion of PID, the immunological and respiratory tests that should be included in the diagnostic process according to the level of care, recommendations regarding the use of immunoglobulin replacement therapy according to the specific immunodeficiency, and the minimum recommended immunological and pulmonary monitoring in these patients.

Conclusions

This document is the first to combine scientific evidence with the opinion of a broad panel of experts specializing in the treatment of patients with immunodeficiencies. It aims to provide a useful tool for all practitioners who are regularly involved in the management of these patients.

A case report of pregnancy in a patient with common variable immunodeficiency emphasizing the need for personalized immunoglobulin replacement

RATIONALE

Subcutaneous immunoglobulin administration facilitated by recombinant human hyaluronidase is a new mode of immunoglobulin replacement. It has been approved for treatment in primary and secondary antibody immunodeficiency. To date, it has not been reported in the literature as therapy of choice during pregnancy.

PATIENT CONCERNS

We report a 31-year-old woman with common variable immunodeficiency (CVID) followed during her first pregnancy.

DIAGNOSES

The patient had a history of increased susceptibility to infections and autoimmune phenomena. From diagnosis at the age 29, she received IVIg replacement with partial response to treatment. Due to medical indications and lack of venous access, we had to search for another mode of application. The patient refused traditional, weekly conventional subcutaneous immunoglobulin (SCIg) administration.

INTERVENTIONS

Immunoglobulin replacement therapy was successfully continued during pregnancy after the IV route was replaced with subcutaneous administration facilitated by recombinant human hyaluronidase. The frequency of infusions was every 3-4 weeks.

OUTCOMES

The treatment was effective and well tolerated by the patient who continued it after delivery. Dosage and the schedule of infusions provided sufficient immunoglobulin G (IgG) levels for the newborn baby.

LESSONS

The presented CVID case illustrates that the selection of the mode of immunoglobulin administration has to be a shared decision, which considers both patient preferences and medical needs. This approach is especially important for the pregnancy period. The case shows that the switch from IVIg to fSCIg can be a management option during pregnancy.

Challenges and Opportunities for the Subcutaneous Delivery of Therapeutic Proteins

Biotherapeutics is a rapidly growing drug class, and over 200 biotherapeutics have already obtained approval, with about 50 of these being approved in 2015 and 2016 alone. Several hundred protein therapeutic products are still in the pipeline, including interesting new approaches to treatment. Owing to patients' convenience of at home administration and reduced number of hospital visits as well as the reduction in treatment costs, subcutaneous (SC) administration of biologics is of increasing interest. Although several avenues for treatment using biotherapeutics are being explored, there is still a sufficient gap in knowledge regarding the interplay of formulation conditions, immunogenicity, and pharmacokinetics (PK) of the absorption of these compounds when they are given SC. This review seeks to highlight the major concerns and important factors governing this route of administration and suggest a holistic approach for effective SC delivery.

Ocular delivery of proteins and peptides: Challenges and novel formulation approaches

The impact of proteins and peptides on the treatment of various conditions including ocular diseases over the past few decades has been advanced by substantial breakthroughs in structural biochemistry, genetic engineering, formulation and delivery approaches. Formulation and delivery of proteins and peptides, such as monoclonal antibodies, aptamers, recombinant proteins and peptides to ocular tissues poses significant challenges owing to their large size, poor permeation and susceptibility to degradation. A wide range of advanced drug delivery systems including polymeric controlled release systems, cell-based delivery and nanowafers are being exploited to overcome the challenges of frequent administration to ocular tissues. The next generation systems integrated with new delivery technologies are anticipated to generate improved efficacy and safety through the expansion of the therapeutic target space. This review will highlight recent advances in formulation and delivery strategies of protein and peptide based biopharmaceuticals. We will also describe the current state of proteins and peptides based ocular therapy and future therapeutic opportunities.

Cost-effectiveness analysis of subcutaneous immunoglobulin replacement therapy in Iranian patients with primary immunodeficiencies

Background: Economic evaluation of subcutaneous immunoglobulin therapy (SCIG) is important, and it has recently been used for treatment of patients with primary immunodeficiency (PID) diseases, and can improve allocation of resources in health care systems. The present research aimed at providing an economic assessment of SCIG and IVIG (intravenous immunoglobulin therapy) administration in Iran. Methods: Data related to clinical effectiveness were obtained from a meta-analysis. Economic analysis was performed taking into account the perspective of health care providers. Incremental cost-effectiveness ratio (ICER) was applied for economic evaluation of the 2 methods, and GDP per capita was considered as a threshold. Results: The results of meta-analysis suggested a higher effectiveness of SCIG compared to IVIG in serum immunoglobulin (Ig) levels (SMD= 0.336) and adverse effects (OR= 0.497), while the cost of IVIG was higher than SCIG ($1370 vs. $121). The ICER obtained in this paper ($2939 for adverse effects and $4348 for serum Ig level) was less than the GDP per capita in Iran ($4,916.10), and thus SCIG is a more cost-effective therapy for PID patients. Conclusion: Switching from IVIG to SCIG is cost-effective for PID patients and is approved by the health care providers' points of view in this study.

Efficacy of Retrobulbar Hyaluronidase Injection for Vision Loss Resulting from Hyaluronic Acid Filler Embolization

BACKGROUND

Vision loss is a rare but serious complication of facial hyaluronic acid (HA) filler injection, for which there is no proven rescue therapy. Retrobulbar hyaluronidase injection is advocated by many plastic surgeons as an emergency treatment, but has not been carefully assessed for its efficacy.

OBJECTIVES

To evaluate the efficacy of retrobulbar hyaluronidase injection as a rescue treatment for vision loss caused by HA filler embolization.

METHODS

Patients with vision loss caused by HA filler embolization were treated with retrobulbar hyaluronidase injection. Their visual acuity and fundoscopic images before and after treatment were analyzed for efficacy assessment.

RESULTS

One patient with branch retinal artery occlusion (BRAO), one patient with posterior ischemic optic neuropathy (PION), one patient with ophthalmic artery occlusion, and one patient with both BRAO and PION were treated with one or two retrobulbar injections of 1500 or 3000 units hyaluronidase. No patients demonstrated substantial retinal artery recanalization or vision acuity improvement after treatment.

CONCLUSIONS

One or two retrobulbar injections of 1500 to 3000 IU hyaluronidase are unable to recanalize retinal artery occlusion or improve the visual outcome of patients who presented with vision loss caused by HA filler embolization at least four hours after onset.

LEVEL OF EVIDENCE

4.

Recombinant human hyaluronidase-facilitated subcutaneous immunoglobulin infusion in primary immunodeficiency diseases

Most primary immunodeficiency diseases (PIDDs) resulting in antibody deficiency require intravenous or subcutaneous immunoglobulin G (SCIG) replacement therapy. The flow and distribution of SCIG to the vasculature is impeded by the glycosaminoglycan hyaluronan in the extracellular matrix, which limits the infusion rate and volume per site, necessitating frequent infusions and multiple infusion sites. Hyaluronidase depolymerizes hyaluronan and is a spreading factor for injectable biologics. Recombinant human hyaluronidase (rHuPH20) increases SCIG absorption and dispersion. In patients with PIDD, SCIG facilitated with rHuPH20 (IGHy) has been shown to prevent infections, be well-tolerated and reduce infusion frequency and number of infusion sites as compared with conventional SCIG. This article reviews IGHy clinical studies and real-world practice data in patients with PIDD.

Immune Gamma Globulin Therapeutic Indications in Immune Deficiency and Autoimmunity

Immune gamma globulin (IgG) has a long history in the treatment of both primary immune deficiency and autoimmune disorders. Disease indications continue to expand and new-generation products increase the versatility of delivery. This review encompasses a historical perspective as well as current and future implications of human immune globulin for the treatment of immune-mediated illness.

Self-administered hyaluronidase-facilitated subcutaneous immunoglobulin therapy in complicated primary antibody deficiencies

Hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIg) is a new immunoglobulin product for replacement therapy in patients with primary antibody deficiencies (PAD). The pre-administration of recombinant human hyaluronidase associated with 10% immunoglobulin allowed the infusion of larger (up to 600 ml) amounts of immunoglobulin at a single infusion site, enabling patients to receive the necessary treatment in a single monthly dose. Here, we report the effectiveness and the tolerability of fSCIg in patients with severe PAD-related comorbidities: refractory autoimmune thrombocytopenia; systemic granulomatous disease; severe enteropathy, and Type I diabetes. We conclude that fSCIg could be a feasible option to improve the adherence to replacement therapy also by patients with severe PAD.

Isolation and characterization of Conohyal-P1, a hyaluronidase from the injected venom of Conus purpurascens

Hyaluronidases are ubiquitous enzymes commonly found in venom and their main function is to degrade hyaluran, which is the major glycosaminoglycan of the extracellular matrix in animal tissues. Here we describe the purification and characterization of a 60kDa hyaluronidase found in the injected venom from Conus purpurascens, Conohyal-P1. Using a combined strategy based on transcriptomic and proteomic analysis, we determined the Conohyal-P1 sequence. Conohyal-P1 has conserved consensus catalytic and positioning domain residues characteristic of hyaluronidases and a C-terminus EGF-like domain. Additionally, the enzyme is expressed as a mixture of glycosylated isoforms at five asparagine sites. The activity of the native Conohyal-P1 was assess MS-based methods and confirmed by classical turbidimetric methods. The MS-based assay is particularly sensitive and provides the first detailed analysis of a venom hyaluronidase activity monitored with this method. The discovery of new hyaluronidases and the development of techniques to evaluate their performance can advance several therapeutic procedures, as these enzymes are widely used for enhanced drug delivery applications.

BIOLOGICAL SIGNIFICANCE

Cone snail venom is a remarkable source of therapeutically important molecules, as is the case of conotoxins, which have undergone extensive clinical trials for several applications. In addition to the conotoxins, a large array of proteins have been reported in the venom of several species of cone snails, including enzymes that were found in dissected and injected Conus venom. Here we describe the isolation and characterization of the hyaluronidase Conohyal-P1 from the injected venom of C. purpurascens. We employed a combined transcriptomic and proteomic analysis to obtain the full sequence of this hyaluronidase. The activity of Conohyal-P1 was assessed by a mass spectrometry-based method, which provide the first detailed venom hyaluronidase activity analysis monitored by mass spectrometry allowing the visualization of the substrate degradation by the enzyme.

Tmem2 Regulates Embryonic Vegf Signaling by Controlling Hyaluronic Acid Turnover

Angiogenesis is responsible for tissue vascularization during development, as well as in pathological contexts, including cancer and ischemia. Vascular endothelial growth factors (VEGFs) regulate angiogenesis by acting through VEGF receptors to induce endothelial cell signaling. VEGF is processed in the extracellular matrix (ECM), but the complexity of ECM control of VEGF signaling and angiogenesis remains far from understood. In a forward genetic screen, we identified angiogenesis defects in tmem2 zebrafish mutants that lack both arterial and venous Vegf/Vegfr/Erk signaling. Strikingly, tmem2 mutants display increased hyaluronic acid (HA) surrounding developing vessels. Angiogenesis in tmem2 mutants was rescued, or restored after failed sprouting, by degrading this increased HA. Furthermore, oligomerized HA or overexpression of Vegfc rescued angiogenesis in tmem2 mutants. Based on these data, and the known structure of Tmem2, we find that Tmem2 regulates HA turnover to promote normal Vegf signaling during developmental angiogenesis.

Mutations in HYAL2, Encoding Hyaluronidase 2, Cause a Syndrome of Orofacial Clefting and Cor Triatriatum Sinister in Humans and Mice

Orofacial clefting is amongst the most common of birth defects, with both genetic and environmental components. Although numerous studies have been undertaken to investigate the complexities of the genetic etiology of this heterogeneous condition, this factor remains incompletely understood. Here, we describe mutations in the HYAL2 gene as a cause of syndromic orofacial clefting. HYAL2, encoding hyaluronidase 2, degrades extracellular hyaluronan, a critical component of the developing heart and palatal shelf matrix. Transfection assays demonstrated that the gene mutations destabilize the molecule, dramatically reducing HYAL2 protein levels. Consistent with the clinical presentation in affected individuals, investigations of Hyal2-/- mice revealed craniofacial abnormalities, including submucosal cleft palate. In addition, cor triatriatum sinister and hearing loss, identified in a proportion of Hyal2-/- mice, were also found as incompletely penetrant features in affected humans. Taken together our findings identify a new genetic cause of orofacial clefting in humans and mice, and define the first molecular cause of human cor triatriatum sinister, illustrating the fundamental importance of HYAL2 and hyaluronan turnover for normal human and mouse development.

Practical Considerations for Self-Administration of Subcutaneous Immunoglobulin G Utilizing Recombinant Human Hyaluronidase, an Advanced Method of Subcutaneous Administration: A Nurse's Perspective

An approved subcutaneous infusion of immunoglobulin G using recombinant human hyaluronidase (IGHy) allows adult patients with primary immunodeficiency disease to self-administer every 3 to 4 weeks using 1 to 2 subcutaneous infusion site(s). This article reviews the practical considerations for nurses to simplify patient education and training. Key considerations include pump choice and parameters, ancillary supplies, and technique. Patient education includes infusion log upkeep and management of potential reactions. Educational initiatives should be designed to meet specific patient needs. Successful IGHy self-administration depends on proper patient training and continuing interaction between the health care team and the patient to optimize the patient experience.

Prophylactic immunoglobulin therapy in secondary immune deficiency - an expert opinion

INTRODUCTION

In primary immunodeficiency (PID), immunoglobulin replacement therapy (IgRT) for infection prevention is well-established and supported by a wealth of clinical data. On the contrary, very little evidence-based data is available on the challenges surrounding the use of IgRT in secondary immune deficiencies (SID), and most published guidelines are mere extrapolations from the experience in PID.

AREAS COVERED

In this article, four European experts provide their consolidated opinion on open questions surrounding the prophylactic use of IgRT in SID, based on their clinical experience. The main topics are IgRT initiation, route of administration, dose optimization, and therapy discontinuation. The authors hope this discussion will be of assistance to practicing physicians in their daily decision-making. Expert commentary: Although growing experience indicates that IgRT could play an important role in the management of SID, very little robust evidence is available to guide clinical practice. The authors stress the urgent need for new studies in the field and discuss points they find of importance to design them adequately.

Quantitative Evidence of Wear-Off Effect at the End of the Intravenous IgG (IVIG) Dosing Cycle in Primary Immunodeficiency

PURPOSE

Intravenous IgG (IVIG) treatment wear-off is commonly experienced by patients, who report increased susceptibility to infection, and decreased quality of life towards the end of their 3- or 4-week dosing cycle, when serum IgG levels approach their trough. We quantified IVIG wear-off in terms of treatment efficacy and patient well-being.

METHODS

Data were collected from patients enrolled in three Phase III trials of Sandoglobulin NF Liquid or Privigen, treated every 3- or 4- weeks. Pooled analyses of raw patient data compared the rate of infection and other clinical outcomes during the course of the dosing cycle. Subjective symptoms of wear-off were quantified by comparing patient-reported overall well-being scores.

RESULTS

The probability of a first infection in the final week of the IVIG cycle was 1.26 (95% confidence intervals [CI]: 0.76-2.11; p = 0.3621) and 1.55 (95% CI: 1.04-2.32; p = 0.0314) times higher than in the first week, for patients on a 3-week cycle and 4-week dosing cycles, respectively. Wear-off, as manifested by a decrease in overall well-being, was experienced in 10% of all cycles and reported at least once by 61% of the patients on a 3-week cycle, and 43% of those on a 4-week cycle.

CONCLUSIONS

These findings confirm the existence of decreased efficacy (treatment wear-off) towards the end of a 3-4 week IVIG dosing cycle, and provide a quantifiable evaluation to a phenomenon typically reported anecdotally. For patients experiencing wear-off, increasing the IgG dose or shortening the dosing interval and/or a switch to SCIG may be beneficial.

Facilitated subcutaneous immunoglobulin (fSCIg) therapy--practical considerations

There is an increasing range of therapeutic options for primary antibody-deficient patients who require replacement immunoglobulin. These include intravenous immunoglobulin (IVIg), subcutaneous immunoglobulin (SCIg), rapid push SCIg and most recently recombinant human hyaluronidase-facilitated SCIg (fSCIg). Advantages of fSCIg include fewer needle punctures, longer infusion intervals and an improved adverse effect profile relative to IVIg. Limited real-life experience exists concerning the practical aspects of switching or starting patients on fSCIg. We describe the first 14 patients who have been treated with fSCIg at the Immunodeficiency Centre for Wales (ICW), representing more than 6 patient-years of experience. The regimen was well tolerated, with high levels of satisfaction and no increase in training requirement, including for a treatment-naive patient. Two patients discontinued fSCIg due to pain and swelling at the infusion site, and one paused therapy following post-infusion migraines. Ultrasound imaging of paired conventional and facilitated SCIg demonstrated clear differences in subcutaneous space distribution associated with a 10-fold increase in rate and volume delivery with fSCIg. Patient profiles for those choosing fSCIg fell into two main categories: those experiencing clinical problems with their current treatment and those seeking greater convenience and flexibility. When introducing fSCIg, consideration of the type and programming of infusion pump, needle gauge and length, infusion site, up-dosing schedule, home training and patient information are important, as these may differ from conventional SCIg. This paper provides guidance on practical aspects of the administration, training and outcomes to help inform decision-making for this new treatment modality.

Human immunoglobulin 10 % with recombinant human hyaluronidase: replacement therapy in patients with primary immunodeficiency disorders

Human immunoglobulin is an established replacement therapy for patients with primary immunodeficiency disorders (PIDs). Recombinant human hyaluronidase (rHuPH20) is a spreading factor that temporarily digests hyaluronan in the skin interstitium enabling large volumes of fluid or drug solutions to be infused and absorbed subcutaneously. HyQvia® (IGHy) is a new combination product whereby rHuPH20 is injected subcutaneously, followed by human immunoglobulin 10 % infused through the same needle. Thus, IGHy can be administered at a reduced frequency compared with non-facilitated subcutaneous injection of human immunoglobulin, and with a lower frequency of infusion reactions than with intravenous administration. Home-based administration of IGHy is also feasible for adequately trained patients. IGHy was compared with intravenous human immunoglobulin 10 % in a non-randomized, open-label, phase 3 study in patients aged ≥2 years with PIDs who were receiving human immunoglobulin replacement therapy (n = 87). In this study, trough IgG concentrations, acute serious bacterial infection rates (primary endpoint) and occurrences of adverse events during the IGHy treatment period were generally similar to those observed during an intravenous treatment period. IGHy was associated with a numerically lower rate of systemic adverse events and a numerically higher rate of localized adverse events than those observed with intravenous treatment. Compared with intravenous administration, IGHy was administered at a significantly higher maximum flow rate and at a similar frequency. Most patients preferred IGHy over intravenous administration. IGHy offers a new method for subcutaneous delivery of human immunoglobulin replacement therapy in patients with PIDs.