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

Engineering protein translocation and unfolded protein response enhanced human PH-20 secretion in Pichia pastoris

Hyaluronidases catalyze the degradation of hyaluronan (HA), which is finding rising applications in medicine, cosmetic, and food industries. Recombinant expression of hyaluronidases in microbial hosts has been given special attention as a sustainable way to substitute animal tissue-derived hyaluronidases. In this study, we focused on optimizing the secretion of hyaluronidase from Homo sapiens in Pichia pastoris by secretion pathway engineering. The recombinant hyaluronidase was first expressed under the control of a constitutive promoter PGCW14. Then, two endoplasmic reticulum-related secretory pathways were engineered to improve the secretion capability of the recombinant strain. Signal peptide optimization suggested redirecting the protein into co-translational translocation using the ost1-proα signal sequence improved the secretion level by 20%. Enhancing the co-translational translocation by overexpressing signal recognition particle components further enhanced the secretory capability by 48%. Then, activating the unfolded protein response by overexpressing a transcriptional factor ScHac1p led to a secreted hyaluronidase activity of 4.06 U/mL, which was 2.1-fold higher than the original strain. Finally, fed-batch fermentation elevated the production to 19.82 U/mL. The combined engineering strategy described here could be applied to enhance the secretion capability of other proteins in yeast hosts. KEY POINTS: • Improving protein secretion by enhancing co-translational translocation in P. pastoris was reported for the first time. • Overexpressing Hac1p homologous from different origins improved the rhPH-20 secretion. • A 4.9-fold increase in rhPH-20 secretion was achieved after fermentation optimization and fed-batch fermentation.

Advances in tumor stroma-based targeted delivery

The tumor stroma plays a crucial role in tumor progression, and the interactions between the extracellular matrix, tumor cells, and stromal cells collectively influence tumor progression and the efficacy of therapeutic agents. Currently, utilizing components of the tumor stroma for drug delivery is a noteworthy strategy. A number of targeted drug delivery systems designed based on tumor stromal components are entering clinical trials. Therefore, this paper provides a thorough examination of the function of tumor stroma in the advancement of targeted drug delivery systems. One approach is to use tumor stromal components for targeted drug delivery, which includes certain stromal components possessing inherent targeting capabilities like HA, laminin, along with targeting stromal cells homologously. Another method entails directly focusing on tumor stromal components to reshape the tumor stroma and facilitate drug delivery. These drug delivery systems exhibit great potential in more effective cancer therapy strategies, such as precise targeting, enhanced penetration, improved safety profile, and biocompatibility. Ultimately, the deployment of these drug delivery systems can deepen our comprehension of tumor stroma and the advanced development of corresponding drug delivery systems.

Substitution of acidic residues near the catalytic Glu131 leads to human HYAL1 activity at neutral pH via charge-charge interactions

Human hyaluronidase 1 (HYAL1) and PH20 play vital roles in degrading hyaluronic acids through the substrate-assisted double displacement mechanism. While HYAL1, a lysosomal enzyme, functions optimally under acidic conditions, PH20, a sperm surface hyaluronidase, displays a broader pH range, from acidic to neutral. Our objective was to extend HYAL1's pH range towards neutral pH by introducing repulsive charge-charge interactions involving the catalytic Glu131, increasing its pKa as the proton donor. Substituting individual acidic residues in the β3-loop (S77D), β3'-β3″ hairpin (T86D and P87E), and at Ala132 (A132D and A132E) enabled HYAL1 to demonstrate enzyme activity at pH 7, with the mutants S77D, P87E, and A132E showing the highest activity in the substrate gel assay. However, double and triple substitutions, including S77D/T86D/A132E as found in the PH20 configuration, did not result in enhanced activity compared to single substitutions. Conversely, PH20 mutants with non-acidic substitutions, such as D94S in the β3-loop and D103T in the β3'-β3″ hairpin, significantly reduced activity within the pH range of 4 to 7. However, the PH20 mutant E149A, reciprocally substituted compared to A132E in HYAL1, exhibited activity similar to PH20 wild-type (WT) at pH 7. In a turbidimetric assay, HYAL1 mutants with single acidic substitutions exhibited activity similar to that of PH20 WT at pH 7. These results suggest that substituting acidic residues near Glu131 results in HYAL1 activity at neutral pH through electrostatic repulsion. This study highlights the significance of charge-charge interactions in both HYAL1 and PH20 in regulating the pH-dependent activity of hyaluronidases.

Deciphering Drug Resistance: Investigating the Emerging Role of Hyaluronan Metabolism and Signaling and Tumor Extracellular Matrix in Cancer Chemotherapy

Hyaluronan (HA) has gained significant attention in cancer research for its role in modulating chemoresistance. This review aims to elucidate the mechanisms by which HA contributes to chemoresistance, focusing on its interactions within the tumor microenvironment. HA is abundantly present in the extracellular matrix (ECM) and binds to cell-surface receptors such as CD44 and RHAMM. These interactions activate various signaling pathways, including PI3K/Akt, MAPK, and NF-κB, which are implicated in cell survival, proliferation, and drug resistance. HA also influences the physical properties of the tumor stroma, enhancing its density and reducing drug penetration. Additionally, HA-mediated signaling contributes to the epithelial-mesenchymal transition (EMT), a process associated with increased metastatic potential and resistance to apoptosis. Emerging therapeutic strategies aim to counteract HA-induced chemoresistance by targeting HA synthesis, degradation, metabolism, or its binding to CD44. This review underscores the complexity of HA's role in chemoresistance and highlights the potential for HA-targeted therapies to improve the efficacy of conventional chemotherapeutics.

Stability of Protein Pharmaceuticals: Recent Advances

There have been significant advances in the formulation and stabilization of proteins in the liquid state over the past years since our previous review. Our mechanistic understanding of protein-excipient interactions has increased, allowing one to develop formulations in a more rational fashion. The field has moved towards more complex and challenging formulations, such as high concentration formulations to allow for subcutaneous administration and co-formulation. While much of the published work has focused on mAbs, the principles appear to apply to any therapeutic protein, although mAbs clearly have some distinctive features. In this review, we first discuss chemical degradation reactions. This is followed by a section on physical instability issues. Then, more specific topics are addressed: instability induced by interactions with interfaces, predictive methods for physical stability and interplay between chemical and physical instability. The final parts are devoted to discussions how all the above impacts (co-)formulation strategies, in particular for high protein concentration solutions.'

Subcutaneous immunoglobulins (SCIG) for chronic inflammatory demyelinating polyneuropathy (CIDP): A comprehensive systematic review of clinical studies and meta-analysis

BACKGROUND

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) presents significant treatment challenges due to its chronic nature, varied clinical presentations, and rarity. Subcutaneous immunoglobulin (SCIG) has emerged as a maintenance therapy, offering potential advantages in administration and patient experience over the previously recognized intravenous immunoglobulin (IVIG).

METHODS

We included all clinical studies involving CIDP patients treated with SCIG from eleven databases up to March 2024.

RESULTS

50 clinical studies were included in the systematic review, with 22 involved in the meta-analysis. These studies offer clinical data on around 1400 CIDP patients. Almost all studies considered SCIG a maintenance therapy, with the majority of results suggesting it as a viable substitute that may offer comparable or enhanced advantages. Studies covered aspects such as efficacy, safety, quality of life, practicality, economic evaluation, and patient preference. Meta-analysis showed SCIG significantly improved muscle strength and sensory function, had fewer and milder side effects, reduced relapse rates, and received a strong preference.

CONCLUSIONS

Findings suggest that SCIG for CIDP maintenance not only provides a more feasible alternative, with economic evaluations showing considerable cost reductions over time, and patient preference for SCIG being pronounced, but may also deliver comparable or superior health outcomes. Ongoing research lines on formulations, techniques, and direct comparative studies are critical to further illuminate, enhance, and expand SCIG's role in treatment.

Broadly neutralizing antibodies for HIV prevention: a comprehensive review and future perspectives

SUMMARYThe human immunodeficiency virus (HIV) epidemic remains a formidable global health concern, with 39 million people living with the virus and 1.3 million new infections reported in 2022. Despite anti-retroviral therapy's effectiveness in pre-exposure prophylaxis, its global adoption is limited. Broadly neutralizing antibodies (bNAbs) offer an alternative strategy for HIV prevention through passive immunization. Historically, passive immunization has been efficacious in the treatment of various diseases ranging from oncology to infectious diseases. Early clinical trials suggest bNAbs are safe, tolerable, and capable of reducing HIV RNA levels. Although challenges such as bNAb resistance have been noted in phase I trials, ongoing research aims to assess the additive or synergistic benefits of combining multiple bNAbs. Researchers are exploring bispecific and trispecific antibodies, and fragment crystallizable region modifications to augment antibody efficacy and half-life. Moreover, the potential of other antibody isotypes like IgG3 and IgA is under investigation. While promising, the application of bNAbs faces economic and logistical barriers. High manufacturing costs, particularly in resource-limited settings, and logistical challenges like cold-chain requirements pose obstacles. Preliminary studies suggest cost-effectiveness, although this is contingent on various factors like efficacy and distribution. Technological advancements and strategic partnerships may mitigate some challenges, but issues like molecular aggregation remain. The World Health Organization has provided preferred product characteristics for bNAbs, focusing on optimizing their efficacy, safety, and accessibility. The integration of bNAbs in HIV prophylaxis necessitates a multi-faceted approach, considering economic, logistical, and scientific variables. This review comprehensively covers the historical context, current advancements, and future avenues of bNAbs in HIV prevention.

Towards more tolerable subcutaneous administration: Review of contributing factors for improving combination product design

Subcutaneous (SC) injections can be associated with local pain and discomfort that is subjective and may affect treatment adherence and overall patient experience. With innovations increasingly focused on finding ways to deliver higher doses and volumes (≥2 mL), there is a need to better understand the multiple intertwined factors that influence pain upon SC injection. As a priority for the SC Drug Development & Delivery Consortium, this manuscript provides a comprehensive review of known attributes from published literature that contribute to pain/discomfort upon SC injection from three perspectives: (1) device and delivery factors that cause physical pain, (2) formulation factors that trigger pain responses, and (3) human factors impacting pain perception. Leveraging the Consortium's collective expertise, we provide an assessment of the comparative and interdependent factors likely to impact SC injection pain. In addition, we offer expert insights and future perspectives to fill identified gaps in knowledge to help advance the development of patient-centric and well tolerated high-dose/high-volume SC drug delivery solutions.

Modeling the subcutaneous pharmacokinetics of antibodies co-administered with rHuPH20

Predicting the subcutaneous (SC) pharmacokinetics (PK) of antibodies in humans is challenging, with clinical data currently being the only reliable data source for modeling SC absorption and bioavailability. Recombinant human hyaluronidase PH20 (rHuPH20) is an enzyme that facilitates SC delivery of high-dose, high-volume therapeutics. Numerous monoclonal antibodies have been co-administered SC with rHuPH20 in a clinical setting, establishing an extensive PK database. The goal of this work is to demonstrate how aggregated clinical data can be leveraged in a universal modeling framework for characterizing SC antibody PK, resulting in parameterization that can be used in predictive simulations of new antibodies. Data for 10 individual antibodies co-administered SC with rHuPH20 were obtained from publicly available sources. PK modeling of each antibody was conducted using the same model structure, but uniquely parameterized. The model structure consisted of a two-compartment model to capture linear kinetics, plus a target-binding mechanism to accommodate nonlinear kinetics driven by antibody-target complex formation and elimination. The clinical PK profiles for all antibodies were accurately described using the universal modeling framework. The SC PK parameters of absorption and bioavailability were consistent across the range of antibody and target properties evaluated. SC administration with rHuPH20 yielded a 30% increase in absorption rate on average and similar or better bioavailability. These parameter values can serve as initial conditions for model-based PK predictions for new antibodies co-administered SC with rHuPH20 to enable evaluation of optimal SC dose and schedule regimens prior to and during clinical development.

Marine polysaccharides: Biological activities and applications in drug delivery systems

The ocean is the common home of a large number of marine organisms, including plants, animals, and microorganisms. Researchers can extract thousands of important bioactive components from the oceans and use them extensively to treat and prevent diseases. In contrast, marine polysaccharide macromolecules such as alginate, carrageenan, Laminarin, fucoidan, chitosan, and hyaluronic acid have excellent physicochemical properties, good biocompatibility, and high bioactivity, which ensures their wide applications and strong therapeutic potentials in drug delivery. Drug delivery systems (DDS) based on marine polysaccharides and modified marine polysaccharide molecules have emerged as an innovative technology for controlling drug distribution on temporal, spatial, and dosage scales. They can detect and respond to external stimuli such as pH, temperature, and electric fields. These properties have led to their wide application in the design of novel drug delivery systems such as hydrogels, polymeric micelles, liposomes, microneedles, microspheres, etc. In addition, marine polysaccharide-based DDS not only have smart response properties but also can combine with the unique biological properties of the marine polysaccharide base to exert synergistic therapeutic effects. The biological activities of marine polysaccharides and the design of marine polysaccharide-based DDS are reviewed. Marine polysaccharide-based responsive DDS are expected to provide new strategies and solutions for disease treatment.

Clinical Investigation of Large Volume Subcutaneous Delivery up to 25 mL for Lean and Non-Lean Subjects

PURPOSE

To evaluate the clinical feasibility and tolerability of large volume subcutaneous delivery at different injection depths for lean and non-lean subjects.

METHODS

A single-center, randomized, subject-blinded, crossover study in 62 healthy subjects was conducted to evaluate delivery of a 10-cP solution containing hyaluronic acid. Subjects were separated into lean and non-lean cohort by SC thickness. A syringe pump was used to study the effect of different volumes (5, 12, 25 mL) of a viscous placebo solution and needle lengths (6, 9 and 12 mm) delivered at 0.5 mL/min.

RESULTS

Across all treatments, injection sites were observed to have negligible leakage, ~34 kPa of back pressure, and VAS of mild pain with higher pain from needle insertion than during injection. While mild to moderate erythema was the most frequently reported ISR and edema was most prominent for 25 mL injections, all ISRs were resolved within 4 hours post injection. Subjects were unbothered by ISRs across all treatments and rated them as low distress scores (average 1.0-1.5 out of 6).

CONCLUSION

SC injection of 25 mL is feasible and tolerable using a low-pain formulation for abdomen injection irrespective of subcutaneous thickness and injection depths at a delivery rate of 0.5 mL/min.

Structural identification and quantification of unreported sialylated N-glycans in bovine testicular hyaluronidase by LC-ESI-HCD-MS/MS

Bovine testicular hyaluronidase (BTH), which accelerates the absorption and dispersion of drugs by decomposing hyaluronan in subcutaneous tissues, has been used in medical applications, including local anesthesia, ophthalmology, and dermatosurgery. The requirement of N-glycans for the activity of human hyaluronidase has been reported, and BTH has greater activity than human hyaluronidase. However, the N-glycan characteristics of BTH are unclear. From a commercial BTH source containing additional proteins, purified BTH (pBTH) was obtained using size exclusion chromatography, and the structures and quantities of its N-glycans were analyzed using liquid chromatography (LC)-electrospray ionization-higher energy collisional dissociation (HCD)-tandem mass spectrometry (MS/MS). In pBTH, 32 N-glycans were identified, with 12 sialylations (39.0% of total N-glycan content), nine core-fucosylations (31.5%), six terminal galactosylations (14.6%), five high-mannosylations (13.7%), and four bisecting N-acetylglucosamine structures (7.8%). The presence of sialylated glycopeptides in pBTH was confirmed by nano-LC-HCD-MS/MS analysis. The absolute quantity of all N-glycans was calculated as 1.4 pmol (0.6 pmol for sialylation) in pBTH (1.0 pmol). The sialylation level (related to half-life, thermal stability, resistance to proteolysis, and solubility) was 24.4 times higher than that of human hyaluronidase. The hyaluronan degradation activity of de-sialylated pBTH decreased to 41.2 ± 4.2%, showing that sialylated N-glycans were required for pBTH activity as well. This is the first study to identify and quantify 32 N-glycans of pBTH and investigate their structural roles in its activity. The presence of larger amounts of sialylated N-glycans in pBTH than in human hyaluronidase suggests a greater utilization of pBTH.

Antibody desolvation with sodium chloride and acetonitrile generates bioactive protein nanoparticles

About 30% of the FDA approved drugs in 2021 were protein-based therapeutics. However, therapeutic proteins can be unstable and rapidly eliminated from the blood, compared to conventional drugs. Furthermore, on-target but off-tumor protein binding can lead to off-tumor toxicity, lowering the maximum tolerated dose. Thus, for effective treatment therapeutic proteins often require continuous or frequent administration. To improve protein stability, delivery and release, proteins can be encapsulated inside drug delivery systems. These drug delivery systems protect the protein from degradation during (targeted) transport, prevent premature release and allow for long-term, sustained release. However, thus far achieving high protein loading in drug delivery systems remains challenging. Here, the use of protein desolvation with acetonitrile as an intermediate step to concentrate monoclonal antibodies for use in drug delivery systems is reported. Specifically, trastuzumab, daratumumab and atezolizumab were desolvated with high yield (∼90%) into protein nanoparticles below 100 nm with a low polydispersity index (<0.2). Their size could be controlled by the addition of low concentrations of sodium chloride between 0.5 and 2 mM. Protein particles could be redissolved in aqueous solutions and redissolved antibodies retained their binding activity as evaluated in cell binding assays and exemplified for trastuzumab in an ELISA.

Hyaluronidase impacts exposures of long-acting injectable paliperidone palmitate in rodent models

A significant challenge in the development of long-acting injectable drug formulations, especially for anti-infective agents, is delivering an efficacious dose within a tolerable injection volume. Co-administration of the extracellular matrix-degrading enzyme hyaluronidase can increase maximum tolerable injection volumes but is untested for this benefit with long-acting injectable formulations. One concern is that hyaluronidase could potentially alter the tissue response surrounding an injection depot, a response known to be important for drug release kinetics of long-acting injectable formulations. The objective of this pilot study was to evaluate the impact of co-administration of hyaluronidase on the drug release kinetics, pharmacokinetic profiles, and injection site histopathology of the long-acting injectable paliperidone palmitate for up to four weeks following intramuscular injection in mouse and rat models. In both species, co-administration of hyaluronidase increased paliperidone plasma exposures the first week after injection but did not negate the overall long-acting release nature of the formulation. Hyaluronidase-associated modification of the injection site depot was observed in mice but not in rats. These findings suggest that further investigation of hyaluronidase with long-acting injectable agents is warranted.

Model-Based Dose Selection of Subcutaneous Nivolumab in Patients with Advanced Solid Tumors

The pharmacokinetics (PK) of intravenous (i.v.) nivolumab is well characterized. A subcutaneous (s.c.) nivolumab formulation with and without recombinant human hyaluronidase PH20 enzyme is being evaluated in CheckMate 8KX (NCT03656718). A model-based analysis was conducted to characterize the PK of nivolumab s.c. and predict systemic exposures after i.v. and s.c. administration to guide dosing regimen selection for nivolumab s.c. A prior i.v. model was modified to incorporate an s.c. extravascular compartment and estimate the absorption rate constant and bioavailability of nivolumab s.c. Serum concentration-time data from 82 patients treated with nivolumab s.c. 720, 960, or 1,200 mg were pooled with existing i.v. data from multiple studies for model development. Prediction-corrected visual predictive check (pcVPC) plots assessed the model's performance. Stochastic simulations were conducted to predict exposures for i.v. and s.c. administration. The data were described by a two-compartment model with time-varying clearance, zero-order infusion into the central compartment after i.v. dosing, and first-order absorption from the extravascular compartment after s.c. dosing. The pcVPC suggested that the model adequately described the observed nivolumab s.c. data. Predicted nivolumab exposures at 1,200 mg s.c. every 4 weeks (q4w) were higher than those at the approved dose of 3 mg/kg i.v. q2w and lower than those at the highest tested safe dose of 10 mg/kg i.v. q2w. Nivolumab PK is well-characterized using the combined s.c./i.v. population PK model. The model-based analysis facilitated a comprehensive benefit-risk assessment of nivolumab s.c. and informed selection of 1,200 mg s.c. q4w for phase III evaluation.

Reversible protein complexes as a promising avenue for the development of high concentration formulations of biologics

High concentration formulations have become an important pre-requisite in the development of biological drugs, particularly in the case of subcutaneous administration where limited injection volume negatively affects the administered dose. In this study, we propose to develop high concentration formulations of biologics using a reversible protein-polyelectrolyte complex (RPC) approach. First, the versatility of RPC was assessed using different complexing agents and formats of therapeutic proteins, to define the optimal conditions for complexation and dissociation of the complex. The stability of the protein was investigated before and after complexation, as well as upon a 4-week storage period at various temperatures. Subsequently, two approaches were selected to develop high concentration RPC formulations: first, using up-concentrated RPC suspensions in aqueous buffers, and second, by generating spray-dried RPC and further resuspension in non-aqueous solvents. Results showed that the RPC concept is applicable to a wide range of therapeutic protein formats and the complexation-dissociation process did not affect the stability of the proteins. High concentration formulations up to 200 mg/mL could be achieved by up-concentrating RPC suspensions in aqueous buffers and RPC suspensions in non-aqueous solvents were concentrated up to 250 mg/mL. Although optimization is needed, our data suggests that RPC may be a promising avenue to achieve high concentration formulations of biologics for subcutaneous administration.

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.

Comparison of efficacy between subcutaneous and intravenous application of moss-aGal in the mouse model of Fabry disease

Fabry disease (FD, OMIM 301500) is a rare X-linked inherited lysosomal storage disorder associated with reduced activities of α-galactosidase A (aGal, EC 3.2.1.22). The current standard of care for FD is based on enzyme replacement therapy (ERT), in which a recombinantly produced version of αGal is intravenously (iv) applied to Fabry patients in biweekly intervals. Though the iv application is clinically efficacious, periodical infusions are inconvenient, time- and resource-consuming and they negatively impact the patients' quality of life. Subcutaneous (sc) injection, in contrast, is an established route of administration for treatment of chronic conditions. It opens the beneficial option of self-administration, thereby improving patients' quality of life and at the same time reducing treatment costs. We have previously shown that Moss-α-Galactosidase (moss-aGal), recombinantly produced in the moss Physcomitrium patens, is efficient in degrading accumulated Gb3 in target organs of murine model of FD and in the phase I clinical study, we obtained first efficacy evidence in human patients following single iv infusion. Here, we tested the efficacy of subcutaneous administration of moss-aGal and compared it with the results observed following iv infusion in Fabry mice. The obtained findings demonstrate that subcutaneously applied moss-aGal is correctly transported to target organs and efficacious in degrading Gb3 deposits there and thus suggest the possibility of using this route of administration for therapy of Fabry disease.

Damage and Fracture Mechanics of Porcine Subcutaneous Tissue Under Tensile Loading

Subcutaneous injection, which is a preferred delivery method for many drugs, causes deformation, damage, and fracture of the subcutaneous tissue. Yet, experimental data and constitutive modeling of these dissipation mechanisms in subcutaneous tissue remain limited. Here we show that subcutaneous tissue from the belly and breast anatomical regions in the swine show nonlinear stress-strain response with the characteristic J-shaped behavior of collagenous tissue. Additionally, subcutaneous tissue experiences damage, defined as a decrease in the strain energy capacity, as a function of the previously experienced maximum deformation. The elastic and damage response of the tissue are accurately described by a microstructure-driven constitutive model that relies on the convolution of a neo-Hookean material of individual fibers with a fiber orientation distribution and a fiber recruitment distribution. The model fit revealed that subcutaneous tissue can be treated as initially isotropic, and that changes in the fiber recruitment distribution with loading are enough to explain the dissipation of energy due to damage. When tested until failure, subcutaneous tissue that has undergone damage fails at the same peak stress as virgin samples, but at a much larger stretch, overall increasing the tissue toughness. Together with a finite element implementation, these data and constitutive model may enable improved drug delivery strategies and other applications for which subcutaneous tissue biomechanics are relevant.

Cancer-related post-treatment pain and its impact on treatment satisfaction with medication in women with breast cancer: a cross-sectional study from Palestine

BACKGROUND

Pain after therapy is an important clinical problem in patients with breast cancer. Unfortunately, cancer patients have a lower quality of life due to inadequate treatment of posttreatment pain; therefore, improving medication management plans and palliative care has become one of the most important targets of cancer therapy. Therefore, the current study aimed to examine the impact of posttreatment pain on medication satisfaction in patients with various stages of breast cancer in Palestine.

METHODS

A cross-sectional analytical study was conducted et al.-Watani Hospital and An-Najah National University Hospital in the Nablus area. Using the Brief Pain Inventory (BPI), the intensity and interference of pain were evaluated. In addition, patients' satisfaction with cancer management medications was measured using the Treatment Satisfaction Questionnaire for Medication (TSQM).

RESULTS

Two hundred fifty-four patients were included in this study. All were women, with a mean ± SD age of 53.1 ± 10.7 years. The median score for pain severity was 7.0. Pain in the lower extremities was the most reported location. There was a negative association between the global satisfaction domain and the presence of posttreatment pain (p < 0.001). Furthermore, significant differences and negative correlations were found between global satisfaction and posttreatment pain on the day of the interview (p = 0.001), pain medication (p < 0.001), paracetamol use (p < 0.001), and the presence of side effects (p = 0.003). There were significant negative correlations (p < 0.05) between pain severity and interference with effectiveness (r = -0.258, -0.319, respectively), side effects (r = -0.414, -0.514, respectively), convenience (r = -0.274, -0.307, respectively), and global satisfaction domain scores (r = -0.293, -0.287, respectively). Exposure to chemotherapy was the only significant positive correlation with global satisfaction (p = 0.007). The regression analysis results indicated an independent association between chemotherapy use and a higher global satisfaction score (p = 0.011).

CONCLUSIONS

Patients with posttreatment pain, side effects, and greater interference of pain with their functioning had lower satisfaction scores. Therefore, better management of their treatment medications, side effects, and pain medications is recommended to enhance their satisfaction and quality of life. Several aspects of palliative care should be organized to improve the patient's satisfaction and quality of life in addition to conducting longitudinal studies to evaluate the pain and satisfaction of different types of cancers.

Effects of Intradermal Administration Volume Using a Hollow Microneedle on the Pharmacokinetics of Fluorescein Isothiocyanate Dextran (M.W. 4,000)

PURPOSE

Hollow microneedles (hMNs) have been gaining attention as a tool to enable the intradermal (i.d.) administration of pharmaceutical products. However, few reports have examined the effect of administration volume on distribution in the skin and pharmacokinetics parameters after i.d. injection. In the present study, a model middle molecular weight compound, fluorescein isothiocyanate dextran (M.W. 4,000, FD-4), was selected, and blood concentration-time profiles after i.d. and subcutaneous (s.c.) injections with different administration volumes were compared.

METHODS

FD-4 solution was injected i.d. using a hMN or injected s.c. with a 27 G needle. Pharmacokinetics and dermatokinetics of FD-4 were analyzed using a compartment model. The skin distribution of iodine, as an X ray tracer, was used to evaluate drug disposition.

RESULTS

With the administered drug assumed to be absorbed from the broad injection site into blood vessels in the upper and lower dermis by rapid (krapid) and slow (kslow) first-order absorption rate constants, respectively, better agreement of observed and theoretical values was obtained. Furthermore, the fraction, F, of the administered dose absorbed with krapid decreased with the increase in injection volume after i.d. injection, although the pharmacokinetics parameters were almost the same regardless of administration volume after s.c. injection.

CONCLUSION

The drug distribution in the skin may be related to the obtained pharmacokinetics parameters suggested that the number of needles in the MN system and the total administration volume should be considered in designing hMN systems. The present results provide useful information that may support effective drug delivery with hMNs.

Application of Allometric Scaling to Nanochelator Pharmacokinetics

Deferoxamine (DFO) is an effective FDA-approved iron chelator; however, its use is considerably limited by off-target toxicities and an extremely cumbersome dose regimen involving daily infusions. The recent development of a deferoxamine-based nanochelator (DFO-NP) with selective renal excretion has shown promise in ameliorating iron overload and associated physiological complications in rodent models with a substantially improved safety profile. While the dose- and administration route-dependent pharmacokinetics (PK) of DFO-NPs have been recently characterized, the optimized PK model was not validated, and the prior studies did not directly address the clinical translatability of DFO-NPs into humans. In the present work, these gaps were addressed by applying allometric scaling of DFO-NP PK in rats to predict those in mice and humans. First, this approach predicted serum concentration-time profiles of DFO-NPs, which were similar to those experimentally measured in mice, validating the nonlinear disposition and absorption models for DFO-NPs across the species. Subsequently, we explored the utility of allometric scaling by predicting the PK profile of DFO-NPs in humans under clinically relevant dosing schemes. These in silico efforts demonstrated that the novel nanochelator is expected to improve the PK of DFO when compared to standard infusion regimens of native DFO. Moreover, reasonable formulation strategies were identified and discussed for both early clinical development and more sophisticated formulation development.

IMscin001 Part 2: a randomised phase III, open-label, multicentre study examining the pharmacokinetics, efficacy, immunogenicity, and safety of atezolizumab subcutaneous versus intravenous administration in previously treated locally advanced or metastatic non-small-cell lung cancer and pharmacokinetics comparison with other approved indications

BACKGROUND

Atezolizumab intravenous (IV) is approved for the treatment of various solid tumours. To improve treatment convenience and health care efficiencies, a coformulation of atezolizumab and recombinant human hyaluronidase PH20 was developed for subcutaneous (SC) use. Part 2 of IMscin001 (NCT03735121) was a randomised phase III, open-label, multicentre, noninferiority study comparing the drug exposure of atezolizumab SC with atezolizumab IV.

PATIENTS AND METHODS

Eligible patients with locally advanced/metastatic non-small-cell lung cancer were randomised 2 : 1 to receive atezolizumab SC (1875 mg; n = 247) or IV (1200 mg; n = 124) every 3 weeks. The co-primary endpoints were cycle 1 observed trough serum concentration (Ctrough) and model-predicted area under the curve from days 0 to 21 (AUC0-21 d). The secondary endpoints were steady-state exposure, efficacy, safety, and immunogenicity. Exposure following atezolizumab SC was then compared with historical atezolizumab IV values across approved indications.

RESULTS

The study met both of its co-primary endpoints: cycle 1 observed Ctrough {SC: 89 μg/ml [coefficient of variation (CV): 43%] versus IV: 85 μg/ml (CV: 33%); geometric mean ratio (GMR), 1.05 [90% confidence interval (CI) 0.88-1.24]} and model-predicted AUC0-21 d [SC: 2907 μg d/ml (CV: 32%) versus IV: 3328 μg d/ml (CV: 20%); GMR, 0.87 (90% CI 0.83-0.92)]. Progression-free survival [hazard ratio 1.08 (95% CI 0.82-1.41)], objective response rate (SC: 12% versus IV: 10%), and incidence of anti-atezolizumab antibodies (SC: 19.5% versus IV: 13.9%) were similar between arms. No new safety concerns were identified. Ctrough and AUC0-21 d for atezolizumab SC were consistent with the other approved atezolizumab IV indications.

CONCLUSIONS

Compared with IV, atezolizumab SC demonstrated noninferior drug exposure at cycle 1. Efficacy, safety, and immunogenicity were similar between arms and consistent with the known profile for atezolizumab IV. Similar drug exposure and clinical outcomes following SC and IV administration support the use of atezolizumab SC as an alternative to atezolizumab IV.

Role of nanotechnology in the prolonged release of drugs by the subcutaneous route

INTRODUCTION

Subcutaneous physiology is distinct from other parenteral routes that benefit the administration of prolonged-release formulations. A prolonged-release effect is particularly convenient for treating chronic diseases because it is associated with complex and often prolonged posologies. Therefore, drug-delivery systems focused on nanotechnology are proposed as alternatives that can overcome the limitations of current therapeutic regimens and improve therapeutic efficacy.

AREAS COVERED

This review presents an updated systematization of nanosystems, focusing on their applications in highly prevalent chronic diseases. Subcutaneous-delivered nanosystem-based therapies comprehensively summarize nanosystems, drugs, and diseases and their advantages, limitations, and strategies to increase their translation into clinical applications. An outline of the potential contribution of quality-by-design (QbD) and artificial intelligence (AI) to the pharmaceutical development of nanosystems is presented.

EXPERT OPINION

Although recent academic research and development (R&D) advances in the subcutaneous delivery of nanosystems have exhibited promising results, pharmaceutical industries and regulatory agencies need to catch up. The lack of standardized methodologies for analyzing in vitro data from nanosystems for subcutaneous administration and subsequent in vivo correlation limits their access to clinical trials. There is an urgent need for regulatory agencies to develop methods that faithfully mimic subcutaneous administration and specific guidelines for evaluating nanosystems.

Safety and pharmacokinetics of escalating doses of neutralising monoclonal antibody CAP256V2LS administered with and without VRC07-523LS in HIV-negative women in South Africa (CAPRISA 012B): a phase 1, dose-escalation, randomised controlled trial

BACKGROUND

Young women in sub-Saharan Africa continue to bear a high burden of HIV infection. Combination anti-HIV monoclonal antibodies are a potential HIV prevention technology that could overcome adherence challenges of daily oral pre-exposure prophylaxis. In this phase 1 clinical trial we aimed to determine the safety and pharmacokinetic profile of the broadly neutralising monoclonal antibody CAP256V2LS.

METHODS

CAPRISA 012B, a first-in-human dose-escalation phase 1 trial evaluated the safety, pharmacokinetics, and neutralisation activity of CAP256V2LS alone and in combination with VRC07-523LS in young HIV-negative women in Durban, South Africa. Groups 1 and 2 were open label with CAP256V2LS administered at 5 mg/kg and 10 mg/kg intravenously and 5 mg/kg, 10 mg/kg, and 20 mg/kg subcutaneously. In group 3, participants were randomly allocated to receive a combination of CAP256V2LS and VRC07-523LS at 10 mg/kg and 20 mg/kg subcutaneously comixed with ENHANZE, a recombinant human hyaluronidase. Once safety was established in the first three participants, dose escalation took place sequentially following review of safety data. Primary endpoints were the proportion of participants with mild, moderate, and severe reactogenicity or adverse events, graded as per the Division of AIDS toxicity grading. The trial is registered on the Pan African Clinical Trial Registry, PACTR202003767867253, and is recruiting.

FINDINGS

From July 13, 2020, to Jan 13, 2021, 42 HIV-negative women, aged 18-45 years, were enrolled. All 42 participants, eight with intravenous and 34 with subcutaneous administration, completed the trial. There were no serious adverse events or dose-limiting toxicities. Most commonly reported symptoms following intravenous administration were headaches in seven (88%) and nausea in four (50%) participants. Commonly reported symptoms following subcutaneous administration were headache in 31 (91%), chills in 25 (74%), and malaise or fatigue in 19 (56%) participants. Adverse events included transient lymphocytopenia in eight (19%), proteinuria in nine (21%), elevated aspartate aminotransferase in ten (24%), and alanine aminotransferase in five (12%) participants.

INTERPRETATION

CAP256V2LS administered alone and in combination with VRC07-523LS was safe with favourable pharmacokinetics and neutralisation activity, supporting further assessment in larger clinical studies.

FUNDING

European and Developing Countries Clinical Trials Partnership, South African Medical Research Council, and South African Department of Science and Innovation.

Pharmacokinetic characterization, benefits and barriers of subcutaneous administration of monoclonal antibodies in oncology

OBJECTIVE

Therapeutic monoclonal antibodies in oncology are slowly becoming the dominant treatment option for many different cancer types. The main route of administration, infusion, requires extensive product preparations, patient hospitalization and close monitoring. Patient comfort improvement, staff workload reduction and cost savings dictated the development of subcutaneous formulations. The aim of this review is to present pharmacokinetic characteristics of subcutaneous products, discuss the differences between intravenous and subcutaneous routes and to point out the advantages as well as challenges of administration route shift from the formulation development and pharmacometric angle.

DATA SOURCES

Food and Drug administration's Purple book database and electronic medicines compendium were used to identify monoclonal antibodies in oncology approved as subcutaneous forms. Using keywords subcutaneous, monoclonal antibodies, pharmacokinetics, model, as well as specific drugs previously identified, both PubMed and ScienceDirect databases were researched.

DATA SUMMARY

There are currently six approved subcutaneous onco-monoclonal antibodies on the market. For each of them, exposure to the drug was similar in relation to infusion, treatment effectiveness was the same, administration was well tolerated by the patients and costs of the medical service were reduced.

CONCLUSION

Development of subcutaneous forms for existing and emerging new monoclonal antibodies for cancer treatment as well as shifting from administration via infusion should be encouraged due to patient preference, lower costs and overall lack of substantial differences in efficacy and safety between the two routes.

Anti-Inflammatory Effects of the 35kDa Hyaluronic Acid Fragment (B-HA/HA35)

Background

Hyaluronic acid (HA) and HA fragments interact with a variety of human body receptors and are involved in the regulation of various physiological functions and leukocyte trafficking in the body. Accordingly, the development of an injectable HA fragment with good tissue permeability, the identification of its indications, and molecular mechanisms are of great significance for its clinical application. The previous studies showed that the clinical effects of injectable 35kDa B-HA result from B-HA binding to multiple receptors in different cells, tissues, and organs. This study lays the foundation for further studies on the comprehensive clinical effects of injectable B-HA.

Methods

We elaborated on the production process, bioactivity assay, efficacy analyses, and safety evaluation of an injectable novel HA fragment with an average molecular weight of 35 kDa (35 kDa B-HA), produced by recombinant human hyaluronidase PH20 digestion.

Results

The results showed that 35 kDa B-HA induced human erythrocyte aggregation (rouleaux formation) and accelerated erythrocyte sedimentation rates through the CD44 receptor. B-HA application and injection treatment significantly promoted the removal of mononuclear cells from the site of inflammation and into the lymphatic circulation. At a low concentration, 35 kDa B-HA inhibited production of reactive oxygen species and tumor necrosis factor by neutrophils; at a higher concentration, 35 kDa B-HA promoted the migration of monocytes. Furthermore, 35 kDa B-HA significantly inhibited the migration of neutrophils with or without lipopolysaccharide treatment, suggesting that in local tissues, higher concentrations of 35 kDa B-HA have antiinflammatory effects. After 99mTc radiolabeled 35 kDa B-HA was intravenously injected into mice, it quickly entered into the spleen, liver, lungs, kidneys and other organs through the blood circulation.

Conclusion

This study demonstrated that the HA fragment B-HA has good tissue permeability and antiinflammatory effects, laying a theoretical foundation for further clinical studies.

Monoclonal antibody and protein therapeutic formulations for subcutaneous delivery: high-concentration, low-volume vs. low-concentration, high-volume

Biologic drugs are used to treat a variety of cancers and chronic diseases. While most of these treatments are administered intravenously by trained healthcare professionals, a noticeable trend has emerged favoring subcutaneous (SC) administration. SC administration of biologics poses several challenges. Biologic drugs often require higher doses for optimal efficacy, surpassing the low volume capacity of traditional SC delivery methods like autoinjectors. Consequently, high concentrations of active ingredients are needed, creating time-consuming formulation obstacles. Alternatives to traditional SC delivery systems are therefore needed to support higher-volume biologic formulations and to reduce development time and other risks associated with high-concentration biologic formulations. Here, we outline key considerations for SC biologic drug formulations and delivery and explore a paradigm shift: the flexibility afforded by low-to-moderate-concentration drugs in high-volume formulations as an alternative to the traditionally difficult approach of high-concentration, low-volume SC formulation delivery.

Hyaluronidase-powered microneedles for significantly enhanced transdermal delivery efficiency

Microneedles (MNs) with enhanced delivery efficiency have revolutionized the transdermal drug delivery system for treating systemic illness. However, the bioavailability of MNs was still far from the clinical requirements by only overcoming the stratum corneum barrier. Herein, hyaluronidase (HAase)-powered MNs were developed as a top-down permeation-enhancement strategy to hijack the sequential transdermal barriers for improved bioavailability. HAase MNs with robust mechanical strength showed excellent skin penetration ability and significantly enhanced the transdermal delivery efficacy of macromolecular drugs as compared to that of HAase-absent MNs, resulting in considerable effect to subcutaneous injection in terms of biodistribution, bioavailability, and therapeutical efficacy. As evidenced from the distribution of trypan blue and fluorescence underlying skin, the positive effects exerted by HAase MNs could be ascribed to the depolymerization of HA that would loosen the subcutaneous space and destruct the extracellular matrix barrier to promote drug diffusion and permeation in larger area and greater depth. Notably, the transient interconversion of keratin from α-helix to β-sheet that might assist the drug residues on the skin surface permeate across the stratum corneum during administration might be another reason not to be ignored. As a labor-saving strategy, HAase-powered MNs offers a promising and painless administration route for macromolecules.

A systematic review of commercial high concentration antibody drug products approved in the US: formulation composition, dosage form design and primary packaging considerations

Three critical aspects that define high concentration antibody products (HCAPs) are as follows: 1) formulation composition, 2) dosage form, and 3) primary packaging configuration. HCAPs have become successful in the therapeutic sector due to their unique advantage of allowing subcutaneous self-administration. Technical challenges, such as physical and chemical instability, viscosity, delivery volume limitations, and product immunogenicity, can hinder successful development and commercialization of HCAPs. Such challenges can be overcome by robust formulation and process development strategies, as well as rational selection of excipients and packaging components. We compiled and analyzed data from US Food and Drug Administration-approved and marketed HCAPs that are ≥100 mg/mL to identify trends in formulation composition and quality target product profile. This review presents our findings and discusses novel formulation and processing technologies that enable the development of improved HCAPs at ≥200 mg/mL. The observed trends can be used as a guide for further advancements in the development of HCAPs as more complex antibody-based modalities enter biologics product development.

A Polymer Prodrug Strategy to Switch from Intravenous to Subcutaneous Cancer Therapy for Irritant/Vesicant Drugs

Chemotherapy is almost exclusively administered via the intravenous (IV) route, which has serious limitations (e.g., patient discomfort, long hospital stays, need for trained staff, high cost, catheter failures, infections). Therefore, the development of effective and less costly chemotherapy that is more comfortable for the patient would revolutionize cancer therapy. While subcutaneous (SC) administration has the potential to meet these criteria, it is extremely restrictive as it cannot be applied to most anticancer drugs, such as irritant or vesicant ones, for local toxicity reasons. Herein, we report a facile, general, and scalable approach for the SC administration of anticancer drugs through the design of well-defined hydrophilic polymer prodrugs. This was applied to the anticancer drug paclitaxel (Ptx) as a worst-case scenario due to its high hydrophobicity and vesicant properties (two factors promoting necrosis at the injection site). After a preliminary screening of well-established polymers used in nanomedicine, polyacrylamide (PAAm) was chosen as a hydrophilic polymer owing to its greater physicochemical, pharmacokinetic, and tumor accumulation properties. A small library of Ptx-based polymer prodrugs was designed by adjusting the nature of the linker (ester, diglycolate, and carbonate) and then evaluated in terms of rheological/viscosity properties in aqueous solutions, drug release kinetics in PBS and in murine plasma, cytotoxicity on two different cancer cell lines, acute local and systemic toxicity, pharmacokinetics and biodistribution, and finally their anticancer efficacy. We demonstrated that Ptx-PAAm polymer prodrugs could be safely injected subcutaneously without inducing local toxicity while outperforming Taxol, the commercial formulation of Ptx, thus opening the door to the safe transposition from IV to SC chemotherapy.

A comprehensive review on methotrexate containing nanoparticles; an appropriate tool for cancer treatment

For more than seven decades, methotrexate has been used all over the world for treatment of different diseases such as: cancer, autoimmune diseases, and rheumatoid arthritis. Several studies have addressed its formula, efficacy, and delivery methods in recent years. These studies have been focused on the effectiveness of different nanoparticles on drug delivery, delivery of the drug to the target cells, and attenuation of harm to the host cell. Whereas, the main usages of methotrexate are in cancer treatment field, this review provided a brief perspective into using different nanoparticles and their role in the treatment of different cancers.

Alternative Routes of Administration for Therapeutic Antibodies—State of the Art

Background: For the past two decades, there has been a huge expansion in the development of therapeutic antibodies, with 6 to 10 novel entities approved each year. Around 70% of these Abs are delivered through IV injection, a mode of administration allowing rapid and systemic delivery of the drug. However, according to the evidence presented in the literature, beyond the reduction of invasiveness, a better efficacy can be achieved with local delivery. Consequently, efforts have been made toward the development of innovative methods of administration, and in the formulation and engineering of novel Abs to improve their therapeutic index. Objective: This review presents an overview of the routes of administration used to deliver Abs, different from the IV route, whether approved or in the clinical evaluation stage. We provide a description of the physical and biological fundamentals for each route of administration, highlighting their relevance with examples of clinically-relevant Abs, and discussing their strengths and limitations. Methods: We reviewed and analyzed the current literature, published as of the 1 April 2022 using MEDLINE and EMBASE databases, as well as the FDA and EMA websites. Ongoing trials were identified using clinicaltrials.gov. Publications and data were identified using a list of general keywords. Conclusions: Apart from the most commonly used IV route, topical delivery of Abs has shown clinical successes, improving drug bioavailability and efficacy while reducing side-effects. However, additional research is necessary to understand the consequences of biological barriers associated with local delivery for Ab partitioning, in order to optimize delivery methods and devices, and to adapt Ab formulation to local delivery. Novel modes of administration for Abs might in fine allow a better support to patients, especially in the context of chronic diseases, as well as a reduction of the treatment cost.

Designing antibodies as therapeutics

Antibody therapeutics are a large and rapidly expanding drug class providing major health benefits. We provide a snapshot of current antibody therapeutics including their formats, common targets, therapeutic areas, and routes of administration. Our focus is on selected emerging directions in antibody design where progress may provide a broad benefit. These topics include enhancing antibodies for cancer, antibody delivery to organs such as the brain, gastrointestinal tract, and lungs, plus antibody developability challenges including immunogenicity risk assessment and mitigation and subcutaneous delivery. Machine learning has the potential, albeit as yet largely unrealized, for a transformative future impact on antibody discovery and engineering.

Characterization and impact of peptide physicochemical properties on oral and subcutaneous delivery

Peptides, an emerging modality within the biopharmaceutical industry, are often delivered subcutaneously with evolving prospects on oral delivery. Barrier biology within the subcutis or gastrointestinal tract is a significant challenge in limiting absorption or otherwise disrupting peptide disposition. Aspects of peptide pharmacokinetic performance and ADME can be mitigated with careful molecular design that tailors for properties such as effective size, hydrophobicity, net charge, proteolytic stability, and albumin binding. In this review, we endeavor to highlight effective techniques in qualifying physicochemical properties of peptides and discuss advancements of in vitro models of subcutaneous and oral delivery. Additionally, we will delineate empirical findings around the relationship of these physicochemical properties and in vivo (animal or human) impact. We conclude that robust peptide characterization methods and in vitro techniques with demonstrated correlations to in vivo data are key routines to incorporate in the drug discovery and development to improve the probability of technical and commercial success of peptide therapeutics.

Hyaluronidase Enhances Targeting of Hydrogel-Encapsulated Anti-CTLA-4 to Tumor Draining Lymph Nodes and Improves Anti-Tumor Efficacy

Immunotherapy targeting checkpoint inhibitors, such as CTLA-4 and/or PD-1, has emerged as a leading cancer therapy. While their combination produces superior efficacy compared to monotherapy, it also magnifies inflammatory and autoimmune toxicity that limits clinical utility. We previously reported that a peri-tumor injection of low-dose hydrogel-encapsulated anti-CTLA-4 produced anti-tumor responses that were equal to, or better than, systemic dosing despite a >80% reduction in total dose. Injection of hydrogel-encapsulated anti-CTLA-4 was associated with low serum exposure and limited autoimmune toxicity, but still synergized with anti-PD-1. In this report, we employ live and ex vivo imaging to examine whether peri-tumor administration specifically targets anti-CTLA-4 to tumor-draining lymph nodes (TDLN) and whether the incorporation of hyaluronidase enhances this effect. Tumor-free survival analysis was also used to measure the impact of hyaluronidase on tumor response. Compared to systemic dosing, peri-tumor injection of hydrogel-encapsulated anti-CTLA-4/DyLight 800 resulted in preferential labeling of TDLN. Incorporating hyaluronidase within the hydrogel improved the rapidity, intensity, and duration of TDLN labeling and significantly improved tumor-free survival. We conclude that hydrogel-encapsulated anti-CTLA acts as a localized antibody reservoir and that inclusion of hyaluronidase optimizes the blockade of CTLA-4 in TDLN and thereby imparts superior anti-tumor immunity.

Delivery strategies in treatments of leukemia

Leukemia is a hematological malignancy associated with the uncontrolled proliferation of mutant progenitors, suppressing the production of normal blood cells. Current treatments, including chemotherapy, radiotherapy, and immunotherapy, still lead to unsatisfactory results with a 5 year survival rate of only 30-50%. The poor prognosis is related to both disease relapse and treatment-associated toxicity. Delivery strategies can improve the in vivo pharmacokinetics of drugs, navigating the therapeutics to target cells or the tumor microenvironment and reversing drug resistance, which maximizes tumor elimination and alleviates systematic adverse effects. This review discusses available FDA-approved anti-leukemia drugs and therapies with a focus on the advances in the development of anti-leukemia drug delivery systems. Additionally, challenges in clinical translation of the delivery strategies and future research opportunities in leukemia treatment are also included.

Site-specific integration as an efficient method for production of recombinant human hyaluronidase PH20 in semi-adherent cells

PH20 is a hyaluronidase enzyme that can hydrolyze the glycosidic bond in hyaluronic acid as the major proteoglycan found in extracellular matrices. In the present study, we constructed and characterized two donor plasmids, one of them with one and the second with two PH20 expression cassettes. The expression vectors were site specifically integrated into the genome of HEK293T cells using PhiC31 integrase system to develop HEK293T stable cell lines secreting His-tagged recombinant human PH20 (rhPH20) in the culture supernatant. The produced rhPH20 was quantified using ELISA and turbidimetric assay tests, and its catalytic activity was also assessed by treating the mouse cumulus-oocyte complexes. Our results showed that the secreted rhPH20 in the culture supernatant had the specific activity of 16,660 IU/mg and the recombinant enzyme was able to remove the cumulus cells from oocytes. The results also indicated that phiC31 enzyme inserted the PH20-expressing donor vectors into the specific pseudo attP sites including 10q21.2 and 20q11.22 in the genome of the target cells with different copy numbers. Taken together, our findings demonstrate that PhiC31 integrase system is able to be applied as a robust tool for efficient production and secretion of soluble and active rhPH20 by HEK293T cells as a semi-adherent human cell line. KEY POINTS: • Efficient production of human recombinant PH20 in a semi-adherent human cell line • Successful application of PhiC31 integrase system for generation of stable recombinant clones • Use of a human cell line for expression of a recombinant human protein due to complex and efficient post-translational modifications and protein folding.

Assessing the transition from intravenous to subcutaneous delivery of rituximab: Benefits for payers, health care professionals, and patients with lymphoma

Subcutaneous (SC) administration of rituximab provides an opportunity for reduced patient treatment burden and increased healthcare efficiencies as an alternative to intravenous (IV) rituximab. There is minimal evidence comparing costs associated with SC and IV rituximab in a US setting. This research assessed the impact of transitioning patients from IV to SC rituximab for treatment of non-Hodgkin’s lymphoma (NHL) from the US payer, provider, and patient perspective. We developed a model to estimate cost differences for transitioning 20% of a patient cohort from IV to SC rituximab. We included patients with incident diffuse large B-cell lymphoma, incident and recurrent follicular lymphoma, and incident and recurrent chronic lymphocytic leukemia. In the model, each patient received the same number of doses and that there was no difference in discontinuation between cohorts due to non-inferior efficacy and a similar safety profile. Model inputs were collected from published literature and publicly available data. Scenario analyses tested the impact of availability of low-cost biosimilars. In the base case (1,000,000 covered lives), we estimated a total of 157 patients, with 769 total drug administrations. A transition of 20% of patients from IV to SC was projected to generate $153,000 in payer savings, increase provider capacity by 270 hours, and free 470 hours of patient time. Scenario analyses suggest SC administration will be cost saving for payers even with a market where biosimilars approach 50% market share. A 20% transition to SC rituximab in a single cohort of patients has the potential to generate significant US health system value in the form of payer savings, increased practice capacity, and patient time.

Patient Centricity Driving Formulation Innovation: Improvements in Patient Care Facilitated by Novel Therapeutics and Drug Delivery Technologies

Innovative formulation technologies can play a crucial role in transforming a novel molecule to a medicine that significantly enhances patients' lives. Improved mechanistic understanding of diseases has inspired researchers to expand the druggable space using new therapeutic modalities such as interfering RNA, protein degraders, and novel formats of monoclonal antibodies. Sophisticated formulation strategies are needed to deliver the drugs to their sites of action and to achieve patient centricity, exemplified by messenger RNA vaccines and oral peptides. Moreover, access to medical information via digital platforms has resulted in better-informed patient groups that are requesting consideration of their needs during drug development. This request is consistent with health authority efforts to upgrade their regulations to advance age-appropriate product development for patients. This review describes formulation innovations contributingto improvements in patient care: convenience of administration, preferred route of administration, reducing dosing burden, and achieving targeted delivery of new modalities.

OUP accepted manuscript

Background

Effective, long-acting prevention approaches are needed to reduce human immunodeficiency virus (HIV) incidence. We evaluated the safety and pharmacokinetics of VRC07-523LS and PGT121 administered subcutaneously alone and in combination as passive immunization for young women in South Africa.

Methods

CAPRISA 012A was a randomized, double-blinded, placebo-controlled, dose-escalation phase 1 trial. We enrolled 45 HIV-negative women into 9 groups and assessed safety, tolerability, pharmacokinetics, neutralization activity, and antidrug antibody levels. Pharmacokinetic modeling was conducted to predict steady-state concentrations for 12- and 24-weekly dosing intervals.

Results

VRC07-523LS and PGT121, administered subcutaneously, were safe and well tolerated. Most common reactogenicity events were injection site tenderness and headaches. Nine product-related adverse events were mild and transient. Median VRC07-523LS concentrations after 20 mg/kg doses were 9.65 μg/mL and 3.86 μg/mL at 16 and 24 weeks. The median week 8 concentration after the 10 mg/kg PGT121 dose was 8.26 μg/mL. Modeling of PGT121 at 20 mg/kg showed median concentrations of 1.37 μg/mL and 0.22 μg/mL at 16 and 24 weeks. Half-lives of VRC07-523LS and PGT121 were 29 and 20 days. Both antibodies retained neutralizing activity postadministration and no antidrug antibodies were detected.

Conclusions

Subcutaneous administration of VRC07-523LS in combination with optimized versions of PGT121 or other antibodies should be further assessed for HIV prevention.

The past, present, and future of enzyme-based therapies

Enzyme-based therapeutics (EBTs) have the potential to tap into an almost unmeasurable amount of enzyme biodiversity and treat myriad conditions. Although EBTs were some of the first biologics used clinically, the rate of development of newer EBTs has lagged behind that of other biologics. Here, we review the history of EBTs, and discuss the state of each class of EBT, their potential clinical advantages, and the unique challenges to their development. Additionally, we discuss key remaining technical barriers that, if addressed, could increase the diversity and rate of the development of EBTs.

US FDA-approved therapeutic antibodies with high-concentration formulation: summaries and perspectives

Thirty four (34) of the total US FDA approved 103 therapeutic antibody drugs, accounts for one third of the total approved mAbs, are formulated with high protein concentration (100 mg/mL or above) which are the focus of this article. The highest protein concentration of these approved mAbs is 200 mg/mL. The dominant administration route is subcutaneous (76%). Our analysis indicates that it may be rational to implement a platform formulation containing polysorbate, histidine and sucrose to accelerate high concentration formulation development for antibody drugs. Since 2015, the FDA approval numbers are significantly increased which account for 76% of the total approval numbers, i.e., 26 out of 34 highly concentrated antibodies. Thus, we believe that the high concentration formulations of antibody drugs will be the future trend of therapeutic antibody formulation development, regardless of the challenges of highly concentrated protein formulations.

Subcutaneous Administration: Evolution, Challenges, and the Role of Hyaluronidase

BACKGROUND

The subcutaneous (SC) route has evolved significantly. More than two dozen chemotherapy and supportive therapies have been approved for use in the oncology setting. Several IV therapies have been approved for the SC route and require a significantly higher volume than historical maximum limits. Differences exist in how these drugs are administered as compared to older chemotherapy agents.

OBJECTIVES

The purpose of this article is to provide a brief history of the SC route and describe its role in cancer treatment. The use of recombinant hyaluronidase is reviewed within the context of SC monoclonal antibodies. Proper administration techniques and interventions for reducing patient discomfort are discussed.

METHODS

Sentinel medical texts, pharmacokinetic studies, manufacturer's recommendations, and peer-reviewed articles were examined.

FINDINGS

The SC route offers several advantages over the oral and IV routes. A clear understanding of anatomical site selection and injection techniques is beneficial for providing requisite patient education.

Polyurethane foam dressings ameliorating local adverse effects of azacitidine: a randomized controlled trial

This study investigated the use of polyurethane foam dressings to prevent local adverse reactions of subcutaneous azacitidine injection. Patients receiving a subcutaneous azacitidine injection were randomly divided into experimental and control groups. A total of 55 patients were included in each group. A polyurethane foam dressing was used to cover the injection site of patients in the experimental group. Conventional treatment was used in the control group. Injection site pain and local skin reactions were assessed after the intervention in both groups. The score and duration of pain, the incidence and duration of local skin adverse reactions, and the incidence of severe reactions in the experimental group were significantly lower than in the control group (p < 0.05). Polyurethane foam dressing can effectively reduce local adverse reactions of subcutaneous injection of azacitidine, relieve pain, shorten the duration of local pain and adverse reactions, and improve the quality of nursing.

Ongoing Challenges to Develop High Concentration Monoclonal Antibody-based Formulations for Subcutaneous Administration: Quo Vadis?

Although many subcutaneously (s.c.) delivered, high-concentration antibody formulations (HCAF) have received regulatory approval and are widely used commercially, formulation scientists are still presented with many ongoing challenges during HCAF development with new mAb and mAb-based candidates. Depending on the specific physicochemical and biological properties of a particular mAb-based molecule, such challenges vary from pharmaceutical attributes e.g., stability, viscosity, manufacturability, to clinical performance e.g., bioavailability, immunogenicity, and finally to patient experience e.g., preference for s.c. vs. intravenous delivery and/or preferred interactions with health-care professionals. This commentary focuses on one key formulation obstacle encountered during HCAF development: how to maximize the dose of the drug? We examine methodologies for increasing the protein concentration, increasing the volume delivered, or combining both approaches together. We discuss commonly encountered hurdles, i.e., physical protein instability and solution volume limitations, and we provide recommendations to formulation scientists to facilitate their development of s.c. administered HCAF with new mAb-based product candidates.