Insufficient immunity led to virologic breakthrough in NAs-treated chronic hepatitis B patients switching to Peg-IFN-ɑ.

BACKGROUND: Virologic breakthrough (VBT) may occur in chronic hepatitis B (CHB) patients after switching from nucleos(t)ide analogues (NAs) to pegylated interferon alpha (Peg-IFN-ɑ). This study aimed to characterize the clinical and immunological features of VBT. METHODS: In NAs-treated patients switching to Peg-IFN-ɑ, innate and adaptive immune cell proportions were examined in peripheral blood and liver biopsy specimens. In vitro effect of IFN-ɑ on the expressions of toll-like receptors 2 (TLR2) and programmed cell death ligand 1 (PDL1) on monocytes, programmed cell death 1 (PD1) on CD8+T cells was examined. Peripheral blood mononuclear cells (PBMCs) were treated with TLR2 agonist and/or PDL1 blockade to evaluate their effect on HBV replication. RESULTS: 33 of 166 patients switching to Peg-IFN-ɑ experienced VBT after NA cessation, with majority being hepatitis B e antigen (HBeAg) positive or having higher hepatitis B core-related antigen (HBcrAg) levels. Patients with VBT exhibited lower proportions of TLR2+monocyte and increased PD1+HBV-specific CD8+T cell during the early phase of Peg-IFN-ɑ therapy after NA cessation in peripheral blood, as well as fewer TLR2+CD68+macrophages but more PDL1+CD68+macrophages and PD1+CD8+T cells in liver tissues. Simultaneous use of TLR2 agonist and PDL1 blockage ex vivo suppressed HBV replication by promoting cytokines production and CD8+T cells cytotoxicity. Upon in vitro IFN-ɑ stimulation, PDL1+monocytes and PD1+CD8+T cells were upregulated, whereas TLR2+monocytes were not increased in PBMC isolated from HBeAg-positive patients, or those with high HBcrAg titers. CONCLUSIONS: In NAs-treated patients, lower TLR2+monocyte and increased PD1+HBV-specific CD8+T cell proportions potentially contribute to VBT after switching to Peg-IFN-ɑ therapy. This insufficient immunity may be associated with the HBeAg status and HBcrAg levels.

Pharmacokinetics Versus In Vitro Antiproliferative Potency to Design a Novel Hyperglycosylated hIFN-α2 Biobetter.

PURPOSE: IFN4N is a glycoengineered version of recombinant human interferon alpha 2 (rhIFN-α2) that was modified to exhibit four N-glycosylation sites. It shows reduced in vitro specific biological activity (SBA) mainly due to R23 mutation by N23. However, it has improved pharmacokinetics and led to a high in vivo antitumor activity in mice. In order to prepare a new IFN-based biobetter, this work compares the influence of glycosylation (affecting pharmacokinetics) with the in vitro antiproliferative SBA on the in vivo efficacy. METHODS: Based on IFN4N, three groups of muteins were designed, produced, and characterized. Group A: variants with the same glycosylation degree (4N) but higher in vitro antiproliferative SBA (R23 restored); group B: muteins with higher glycosylation degree (5N) but similar in vitro antiproliferative activity; and group C: variants with improved glycosylation (5N and 6N) and in vitro antiproliferative bioactivity. RESULTS: Glycoengineering was successful for improving pharmacokinetics, and R23 restoration considerably increased in vitro antiproliferative activity of new muteins compared to IFN4N. Hyperglycosylation was able to improve the in vivo efficacy similarly to or even better than R23 restoration. Additionally, the highest glycosylated mutein exhibited the lowest immunogenicity. CONCLUSIONS: Hyperglycosylation constitutes a successful strategy to prepare a novel IFN biobetter.

A pharmacokinetic evaluation of ropeginterferon alfa-2b in the treatment of polycythemia vera.

INTRODUCTION: Polycythemia vera (PV) is a Philadelphia chromosome-negative chronic myeloproliferative neoplasm (MPN). A newly developed PV treatment option, ropeginterferon alfa-2b, contains recombinant human alfa monoisomer as an active ingredient, resulting in a novel pharmacologic profile and improved tolerability. Efficacy studies conclude remarkable long-term hematological response and sustained JAK2V617F allele burden reduction. Ropeginterferon alfa-2b compound has been approved for the treatment of polycythemia vera without symptomatic splenomegaly. AREAS COVERED: Current clinical trials are investigating the role of ropeginterferon alfa-2b in the first-line setting of treatment for PV. The safety and efficacy results of completed trials are summarized in this review. Metabolic, pharmacokinetic issues are also discussed of ropeginterferon alfa-2b. EXPERT OPINION: Ropeginterferon alfa-2b is a targeted therapeutic option in the treatment of PV, representing a significant improvement compared to conventional cytoreductive therapies. The single isomer entity of the recombinant human interferon alfa-2b and the mono-pegylation method imparts favorable properties to the compound. The use of ropeginterferon alfa-2b allows extended dosing interval, reduces side effects, and may increase the overall survival of PV patients by reducing the risk of progression to myelofibrosis or acute leukemia. Clinical data suggests that the compound may provide a disease-modifying option for PV patients with asymptomatic splenomegaly.

Effect of ANITVNITV peptide fusion on the bioactivity and pharmacokinetics of human IFN-α2b and a hyper-N-glycosylated variant.

Different strategies have been developed and successfully applied to biotherapeutics in order to improve their in vivo efficacy. The genetic fusion to natural or synthetic glycosylated peptides constitutes a promising strategy since it conserves the protein sequence and results in the improvement of the pharmacokinetic properties. The ANITVNITV peptide described by Perlmann and coworkers presents 9 amino acids and 2 potential N-glycosylation sites. Its fusion to FSH resulted in the increase of the molecular mass and negative charge of the protein. Consequently, the pharmacokinetics was considerably improved. The aim of the present study was to compare the influence of ANITVNITV peptide fusion on the physicochemical, biological and pharmacokinetic properties of native hIFN-α2b (IFNwt), which contains a single O-glycosylation site, and a hyperglycosylated variant (IFN4N), that bears, in addition, 4 N-linked glycans. The resulting molecules, IFNwtNter and IFN4NNter, evidenced a higher molecular mass and negative charge compared to IFNwt and IFN4N, respectively. Therefore, the pharmacokinetic properties of the new molecules were significantly improved. The molecules obtained by the synthetic peptide fusion strategy evidenced a decrease in their in vitro antiviral specific biological activities (SBA). However, in vitro antiproliferative SBA was differentially modified for IFNwtNter and IFN4NNter in comparison with the parental molecules. For IFNwtNter, a reduction in the antiproliferative SBA was also observed. Remarkably, the addition of the ANITVNITV peptide to the N-terminus of IFN4N had a positive impact on its growth-inhibitory activity. This feature together with its improved pharmacokinetics encourages the development of IFN4NNter as an IFN-α based biobetter.

Half-life extension of porcine interferon-α by fusion to the IgG-binding domain of streptococcal G protein.

Recombinant interferon-α (rIFN-α) has been widely used for treating viral infections. However, the clinical efficacy of unmodified rIFN-α is limited due to small molecular size and rapid clearance from circulation. In this study we developed a novel strategy for half-life extension of porcine IFN-α (PoIFN-α) by fusion to the immunoglobulin (Ig)-binding C2 domain of streptococcal protein G (SPG). The coding sequences for PoIFN-α6 and SPG C2 domain, with a tobacco etch virus (TEV) protease recognition sequence introduced at the 5-end, were cloned into an elastin-like polypeptide (ELP) fusion expression vector and expressed as an ELP-PoIFNα-C2 fusion protein. After optimization of the conditions for soluble protein expression and purification, the fusion protein was purified to more than 90% purity by two rounds of inverse transition cycling (ITC) in the presence of 0.5% Triton X-100. After cleavage with self-aggregating peptide ELK-16-tagged tobacco etch virus protease, the protease was removed by quick centrifugation and PoIFNα-C2 protein was recovered by an additional round of ITC with 98% purity. Western blotting analysis showed that PoIFNα-C2 protein had the specific affinity for pig IgG binding. The antiviral assay showed that PoIFNα-C2 protein had potent antiviral activities against vesicular stomatitis virus and porcine pseudorabies virus. After single intravenous or subcutaneous injection into rats, PoIFNα-C2 protein showed 16- or 4-fold increase in serum half-life with significantly improved bioavailability.

Novel therapeutic approaches in polycythemia vera.

Polycythemia vera (PV) is the most common Philadelphia chromosome-negative myeloproliferative neoplasm. Whereas low-risk patients are treated with aspirin and phlebotomy, high-risk patients receive cytoreductive therapy, which most commonly consists of hydroxyurea in the United States. Concerns about the long-term safety of hydroxyurea, as well as a desire for more efficacious and targeted therapy, have led to the development of novel therapies for high-risk patients with PV. Pegylated interferon (IFN) has shown promise in phase 2 studies of PV, and preliminary data from ongoing phase 3 studies suggest noninferiority as a frontline therapy. Efficient count control, tolerability, and even molecular responses as a salvage therapy have been demonstrated. Ropeginterferon-α-2b, a monopegylated IFN with a longer half-life and less frequent dose interval compared with recombinant or pegylated IFN, is an impressive agent in development. Ruxolitinib has a proven role as second-line therapy for PV, but an ongoing trial combining ruxolitinib and IFN as salvage therapy is under way. Early-phase clinical trials have also suggested that MDM2 inhibitors such as idasanutlin and histone deacetylase inhibitors should continue in their development. If these novel agents are able to modify the natural history of PV, the treatment paradigm in newly diagnosed patients will evolve from risk-adapted or reactive treatment toward early interventions.

One-month zero-order sustained release and tumor eradication after a single subcutaneous injection of interferon alpha fused with a body-temperature-responsive polypeptide.

Most therapeutic proteins except antibodies necessitate frequent dosing at high concentrations due to their short circulation half-lives, leading to limited therapeutic efficacy, serious adverse side effects and poor patient compliance. Herein we report a strategy of thermoresponsive polypeptide fusion to genetically engineer a super-long-acting interferon alpha fused with a body-temperature-responsive polypeptide. After a single subcutaneous injection in a mouse model, this interferon alpha can in situ form a depot to show a one-month zero-order sustained release, which would enable a once-trimonthly dosing in humans. As a result, it exhibits greatly enhanced tumor accumulation and tumor eradication as well as substantially improved tolerability and biosafety. This strategy provides a promising solution to dramatically enhance the pharmacological performance of therapeutic proteins with short circulation half-lives while reducing the side effects.

HeberFERON, a new formulation of IFNs with improved pharmacodynamics: Perspective for cancer treatment.

The rational combination of recombinant IFN-α2b and IFN-γ resulted in a new formulation of interferons (HeberFERON) with improved pharmacodynamics. In basal cell carcinomas HeberFERON produces a more rapid antitumor effect and results in a larger number of complete responses. In patients with glioblastoma multiforme, the administration of HeberFERON after surgery and radiotherapy results in an estimated overall survival of 19 months. Patients with stage III or IV renal cell carcinoma also appear to benefit from the intravenous administration of HeberFERON, with prolongation of survival and good quality of live. HeberFERON offers a promising alternative formulation of interferons for the treatment of cancer with a very favorable safety profile.

Peginterferon alfa-2a for the treatment of chronic hepatitis C in the era of direct-acting antivirals.

BACKGROUND: The availability of novel direct-acting antivirals (DAAs) represents a new era of curative hepatitis C virus (HCV) treatment, with over 95% of patients infected with HCV genotype 1 achieving sustained virological response (SVR). Nevertheless, the majority of patients globally are unable to access these treatments because of cost and infrastructure constraints and, thus, remain untreated and uncured. DATA SOURCE: Relevant articles of peginterferon (PegIFN)-based treatments in HCV and sofosbuvir-based treatments, simeprevir, daclatasvir/asunaprevir, ritonavir-boosted paritaprevir/ombitasvir/dasabuvir, and grazoprevir/elbasvir, were searched in PubMed database, including general population and special population. RESULTS: PegIFN in combination with ribavirin remains an important and relevant option for some patients, achieving SVR rates of up to 79% in genotype 1 and 89% in genotype 2 or 3 infections, which increases for patients with favorable IL28B genotypes. Triple therapy of DAA plus PegIFN/ribavirin is effective in treating difficult-to-cure patients infected with HCV genotype 3 or with resistance-associated variants. Owing to its long history in HCV management, the efficacy, tolerability and long-term outcomes associated with PegIFN alfa-2a are well established and have been validated in large-scale studies and in clinical practice for many populations. Furthermore, emerging data show that IFN-induced SVR is associated with lower incidences of hepatocellular carcinoma compared with DAAs. On the contrary, novel DAAs have yet to be studied in special populations, and long-term outcomes, particularly tumor development and recurrence in patients with cirrhosis and/or hepatocellular carcinoma, and reactivation of HBV in dually infected patients, are still unclear. CONCLUSION: In this interferon-free era, PegIFN-based regimens remain a safe and effective option for selected HCV patients.

An Evaluation of Optimal PEGylation Strategies for Maximizing the Lymphatic Exposure and Antiviral Activity of Interferon after Subcutaneous Administration.

Interferon α2 is an antiviral/antiproliferative protein that is currently used to treat hepatitis C infections and several forms of cancer. Two PEGylated variants of interferon α2 (containing 12 and 40 kDa PEGs) are currently marketed and display longer plasma circulation times than that of unmodified interferon. With increasing realization that the lymphatic system plays an important role in the extrahepatic replication of the hepatitis C virus and in the metastatic dissemination of cancers, this study sought to evaluate PEGylation strategies to optimally enhance the antiviral activity and plasma and lymphatic exposure of interferon after subcutaneous administration in rats. The results showed that conjugation with a linear 20 kDa PEG provided the most ideal balance between activity and plasma and lymph exposure. A linear 5 kDa PEG variant also exhibited excellent plasma and lymph exposure to interferon activity when compared to those of unmodified interferon and the clinically available linear 12 kDa PEGylated construct.

Tissue and time specific expression pattern of interferon regulated genes in the chicken.

BACKGROUND: Type I interferons are major players against viral infections and mediate their function by the induction of Interferon regulated genes (IRGs). Recently, it became obvious that these cytokines have a multitude of additional functions. Due to the unique features of the chickens' immune system, available data from mouse models are not easily transferable; hence we performed an extensive analysis of chicken IRGs. RESULTS: A broad database search for homologues to described mammalian IRGs (common IRGs, cIRGs) was combined with a transcriptome analysis of spleen and lung at different time points after application of IFNα. To apply physiological amounts of IFN, half-life of IFN in the chicken was determined. Interestingly, the calculated 36 min are considerably shorter than the ones obtained for human and mouse. Microarray analysis revealed many additional IRGs (newly identified IRGs; nIRGs) and network analysis for selected IRGs showed a broad interaction of nIRGs among each other and with cIRGs. We found that IRGs exhibit a highly tissue and time specific expression pattern as expression quality and quantity differed strongly between spleen and lung and over time. While in the spleen for many affected genes changes in RNA abundance peaked already after 3 h, an increasing or plateau-like regulation after 3, 6 and 9 h was observed in the lung. CONCLUSIONS: The induction or suppression of IRGs in chickens is both tissue and time specific and beside known antiviral mechanisms type I IFN induces many additional cellular functions. We confirmed many known IRGs and established a multitude of so far undescribed ones, thus providing a large database for future research on antiviral mechanisms and additional IFN functions in non-mammalian species.

Pharmacokinetic and pharmacodynamic characterization of a novel formulation containing co-formulated interferons alpha-2b and gamma in healthy male volunteers.

BACKGROUND: More potent antitumor activity is desired in Interferon (IFN)-treated cancer patients. This could be achieved by combining IFN alpha and IFN gamma. The aim of this work was to characterize the pharmacokinetics and pharmacodynamics of a novel formulation containing a co-formulated combination of IFNs alpha-2b and gamma (CIGB-128-A). METHODS: A group of nine healthy male subjects received intramuscularly 24.5 × 106 IU of CIGB-128-A. IFN concentrations were evaluated for 48 h. Serum neopterin, beta2-microglobulin (ß2M) and 2'-5' oligoadenylate synthetase (2'-5' OAS), classical IFN-inducible serum markers, were measured during 192 h by enzyme immunoassay and body temperature was used as pharmacodynamic variable as well. RESULTS: Concerning pharmacokinetics, serum IFNs' profiles were better fitted to a mono-compartmental model with consecutive zero order and first order absorption, one bioavailability value. No interferences by simultaneous administered IFNs were observed in their typical similar systemic profiles. Neopterin and ß2M time profiles showed a delay that was efficiently linked to pharmacokinetics by means of a zero order absorption rate constant. Neopterin level was nine-fold higher than initial values, 48 h post-administration, an increment not described before. At this time, mean serum ß2M peaked around the double from baseline. Serum concentrations of the enzyme 2'-5' OAS was still elevated on the 8 day post-injection. The formulation was well tolerated. Most frequent adverse reactions were fever, headache, arthralgia and lymphopenia, mostly mild. CONCLUSIONS: The administration of co-formulated IFN alpha-2b and IFN gamma likely provides improved pharmacodynamic properties that may be beneficial to treat several malignancies. TRIAL REGISTRATION: Cuban Public Registry of Clinical Trials RPCEC00000118 , May 24, 2011.

Site-Specific Transglutaminase-Mediated Conjugation of Interferon α-2b at Glutamine or Lysine Residues.

Interferon α (IFN α) subtypes are important protein drugs that have been used to treat infectious diseases and cancers. Here, we studied the reactivity of IFN α-2b to microbial transglutaminase (TGase) with the aim of obtaining a site-specific conjugation of this protein drug. Interestingly, TGase allowed the production of two monoderivatized isomers of IFN with high yields. Characterization by mass spectrometry of the two conjugates indicated that they are exclusively modified at the level of Gln101 if the protein is reacted in the presence of an amino-containing ligand (i.e., dansylcadaverine) or at the level of Lys164 if a glutamine-containing molecule is used (i.e., carbobenzoxy-l-glutaminyl-glycine, ZQG). We explained the extraordinary specificity of the TGase-mediated reaction on the basis of the conformational features of IFN. Indeed, among the 10 Lys and 12 Gln residues of the protein, only Gln101 and Lys164 are located in highly flexible protein regions. The TGase-mediated derivatization of IFN was then applied to the production of IFN derivatives conjugated to a 20 kDa polyethylene glycol (PEG), using PEG-NH2 for Gln101 derivatization and PEG modified with ZQG for Lys164 derivatization. The two mono-PEGylated isomers of IFN were obtained in good yields, purified, and characterized in terms of protein conformation, antiviral activity, and pharmacokinetics. Both conjugates maintained a native-like secondary structure, as indicated by far-UV circular dichroism spectra. Importantly, they disclosed good in vitro antiviral activity retention (about only 1.6- to 1.8-fold lower than that of IFN) and half-lives longer (about 5-fold) than that of IFN after intravenous administration to rats. Overall, these results provide evidence that TGase can be used for the development of site-specific derivatives of IFN α-2b possessing interesting antiviral and pharmacokinetic properties.

In situ growth of a C-terminal interferon-alpha conjugate of a phospholipid polymer that outperforms PEGASYS in cancer therapy.

Conjugating therapeutic proteins and peptides to poly(ethylene glycol) (PEG) can improve their pharmacokinetics and therapeutic potential. However, PEGylation suffers from non-specific conjugation, low yield and immunogenicity. Herein we report a new and general methodology to synthesize a protein-polymer conjugate with site-specificity, high yield and activity, long circulation half-life and excellent therapeutic efficacy. A phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), was grown solely from the C-terminus of interferon-alpha to form a site-specific (C-terminal) and stoichiometric (1:1) PMPC conjugate of interferon-alpha in high yield. Notably, the PMPC conjugate showed 194- and 158-fold increases in systemic exposure and tumor uptake as compared with interferon-alpha, respectively. The in vitro antiproliferative bioactivity of the PMPC conjugate was 8.7-fold higher than that of PEGylated interferon-alpha (PEGASYS). In a murine cancer model, the PMPC conjugate completely inhibited tumor growth and cured 75% mice, whereas at the same dose, no mice treated with interferon-alpha or PEGASYS survived. We believe that this new approach to synthesize C-terminal protein conjugates of PMPC may be applicable to a large subset of protein and peptide drugs, thereby providing a general platform for the development of next-generation protein therapeutics.

Site-specific in situ growth of an interferon-polymer conjugate that outperforms PEGASYS in cancer therapy.

Conjugating poly(ethylene glycol) (PEG), PEGylation, to therapeutic proteins is widely used as a means to improve their pharmacokinetics and therapeutic potential. One prime example is PEGylated interferon-alpha (PEGASYS). However, PEGylation usually leads to a heterogeneous mixture of positional isomers with reduced bioactivity and low yield. Herein, we report site-specific in situ growth (SIG) of a PEG-like polymer, poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA), from the C-terminus of interferon-alpha to form a site-specific (C-terminal) and stoichiometric (1:1) POEGMA conjugate of interferon-alpha in high yield. The POEGMA conjugate showed significantly improved pharmacokinetics, tumor accumulation and anticancer efficacy as compared to interferon-alpha. Notably, the POEGMA conjugate possessed a 7.2-fold higher in vitro antiproliferative bioactivity than PEGASYS. More importantly, in a murine cancer model, the POEGMA conjugate completely inhibited tumor growth and eradicated tumors of 75% mice without appreciable systemic toxicity, whereas at the same dose, no mice treated with PEGASYS survived for over 58 days. The outperformance of a site-specific POEGMA conjugate prepared by SIG over PEGASYS that is the current gold standard for interferon-alpha delivery suggests that SIG is of interest for the development of next-generation protein therapeutics.

Phase I study of pegylated interferon-alpha-2b as an adjuvant therapy in Japanese patients with malignant melanoma.

In the adjuvant setting for malignant melanoma, interferon (IFN)-α-2b and pegylated (PEG) IFN-α-2b were approved in several countries including the USA before these were approved in Japan. To resolve the "drug-lag" issue, this phase I study was designed to evaluate the safety and tolerability in Japanese patients with stage II or III malignant melanoma who had undergone surgery, by treating with PEG IFN-α-2b. As with a previously reported phase III study, patients were to receive PEG IFN-α-2b 6 µg/kg per week s.c. during an 8-week induction phase, followed by a maintenance phase at a dose of 3 µg/kg per week up to 5 years. Dose-limiting toxicity and pharmacokinetics were assessed during the initial 8 weeks. Of the nine patients enrolled, two patients had dose-limiting toxicities that resolved after discontinuation of treatment. The most frequently reported drug-related adverse events (DRAE) included pyrexia, decreased neutrophil and white blood cell counts, and arthralgia. Grade 3 DRAE included decreased neutrophil count. No deaths, serious adverse events and grade 4 adverse events were reported. Distant metastasis occurred in one patient. No apparent differences in area under the concentration-time curve and maximum observed serum concentration were observed between Japanese and historical non-Japanese pharmacokinetic data, suggesting no marked racial differences. No neutralizing antibody was detected in these patient samples. PEG IFN-α-2b was tolerated in Japanese patients, and eventually approved in Japan in May 2015 for adjuvant therapy in patients with stage III malignant melanoma. Because the number of patients was limited, further investigation would be crucial.

CDKN2A-independent role of BMI1 in promoting growth and survival of Ph+ acute lymphoblastic leukemia.

BMI1 is a key component of the PRC1 (polycomb repressive complex-1) complex required for maintenance of normal and cancer stem cells. Its aberrant expression is detected in chronic myeloid leukemia and Ph+ acute lymphoblastic leukemia (ALL), but no data exist on BMI1 requirement in ALL cells. We show here that BMI1 expression is important for proliferation and survival of Ph+ ALL cells and for leukemogenesis of Ph+ cells in vivo. Levels of BIM, interferon-α (IFNα)-regulated genes and E2F7 were upregulated in BMI1-silenced cells, suggesting that repressing their expression is important for BMI1 biological effects. Consistent with this hypothesis, we found that: (i) downregulation of BIM or E2F7 abrogated apoptosis or rescued, in part, the reduced proliferation and colony formation of BMI1 silenced BV173 cells; (ii) BIM/E2F7 double silencing further enhanced colony formation and in vivo leukemogenesis of BMI1-silenced cells; (iii) overexpression of BIM and E2F7 mimicked the effect of BMI1 silencing in BV173 and SUP-B15 cells; and (iv) treatment with IFNα suppressed proliferation and colony formation of Ph+ ALL cells. These studies indicate that the growth-promoting effects of BMI1 in Ph+ ALL cells depend on suppression of multiple pathways and support the use of IFNα in the therapy of Ph+ ALL.

Simeprevir plus peginterferon/ribavirin for HCV genotype 1-infected treatment-naïve patients in China and South Korea.

BACKGROUND AND AIM: Approximately one-third of patients with hepatitis C virus (HCV) genotype (GT) 1 infection live in East Asia. This study evaluated the efficacy, pharmacokinetics, safety, and tolerability of simeprevir plus peginterferon alpha-2a and ribavirin (PR) in HCV GT1-infected, treatment-naïve, Asian patients with compensated liver disease. METHODS: This phase III, randomized study (NCT01725529) was conducted in China and South Korea. Patients received simeprevir 150 mg once daily (QD), simeprevir 100 mg QD, or placebo, in combination with PR for 12 weeks. Patients in the simeprevir groups received PR alone for a further 12 or 36 weeks based on response-guided treatment criteria. Patients in the placebo group received a further 36 weeks of PR alone. The primary efficacy endpoint was sustained virologic response 12 weeks after planned end of treatment (SVR12). Secondary endpoints were safety, pharmacokinetics, tolerability, and patient-reported outcomes. RESULTS: Overall, 457 patients were treated; the majority had GT1b infection (452/457 [99%]) and IL28B CC GT (364/457 [80%]). Of the 454 patients who had liver biopsy, 26 had cirrhosis (6%). SVR12 rates were superior for both the simeprevir 100 mg (89%; P = 0.003) and 150 mg (91%; P < 0.001) groups versus placebo (76%). Adverse events were mainly grade 1/2 and occurred at a similar incidence across all treatment groups. Overall, eight patients (2%) discontinued simeprevir or placebo treatment because of adverse events. CONCLUSIONS: Both simeprevir (100 mg and 150 mg QD) plus PR achieved superiority in SVR12 versus placebo plus PR in treatment-naïve, HCV GT1-infected, Asian patients and were well tolerated.

Microstructured dextran hydrogels for burst-free sustained release of PEGylated protein drugs.

Hydrogels have gained significant attention as ideal delivery vehicles for protein drugs. However, the use of hydrogels for protein delivery has been restricted because their porous structures inevitably cause a premature leakage of encapsulated proteins. Here, we report a simple yet effective approach to regulate the protein release kinetics of hydrogels through the creation of microstructures, which serve as a reservoir, releasing their payloads in a controlled manner. Microstructured dextran hydrogels enable burst-free sustained release of PEGylated interferon over 3 months without compromising its bioactivity. These hydrogels substantially extend the circulation half-life of PEGylated interferon, allowing for less frequent dosing in a humanized mouse model of hepatitis C. The present approach opens up possibilities for the development of sustained protein delivery systems for a broad range of pharmaceutical and biomedical applications.

Optimal PEGylation can improve the exposure of interferon in the lungs following pulmonary administration.

The utility of inhaled protein therapeutics to treat lung-resident diseases is limited by protein degradation in the lungs and rapid clearance. This study therefore aimed to evaluate the impact of PEGylation on the lung and systemic exposure of interferon (IFN) α2 after intratracheal administration to rats. An inverse correlation was observed between PEG chain length and systemic exposure, where bioavailability was 5.5% for the 31 kDa PEGylated construct and <0.4% for the 60 kDa PEGylated construct when compared with 15% for native IFN (19 kDa). Retention of PEGylated IFNα within the lungs increased 2.5-fold to threefold when compared with native IFN. When comparing the lung and systemic exposure of PEGylated and native IFN in terms of protein biological activity, the 31 kDa PEGylated construct increased exposure by 50% and 100%, respectively, when compared with native IFN, but the 60 kDa PEG construct offered no benefit. Preliminary work also indicated that the conjugation of IFNγ with 10 kDa PEG significantly increases the retention of the protein within the lung. Optimal PEGylation may therefore be used as a means to improve the exposure of lung-resident diseases to therapeutic cytokines and potentially reduce systemic exposure and side effects as well as dosing frequency.