Accelerated clearance by antibodies against methoxy PEG depends on pegylation architecture

Methoxy polyethylene glycol (mPEG) is attached to many proteins, peptides, nucleic acids and nanomedicines to improve their biocompatibility. Antibodies that bind PEG are present in many individuals and can be generated upon administration of pegylated therapeutics. Anti-PEG antibodies that bind to the PEG "backbone" can accelerate drug clearance and detrimentally affect drug activity and safety, but no studies have examined how anti-methoxy PEG (mPEG) antibodies, which selectively bind the terminus of mPEG, affect pegylated drugs. Here, we investigated how defined IgG and IgM monoclonal antibodies specific to the PEG backbone (anti-PEG) or terminal methoxy group (anti-mPEG) affect pegylated liposomes or proteins with a single PEG chain, a single branched PEG chain, or multiple PEG chains. Large immune complexes can be formed between all pegylated compounds and anti-PEG antibodies but only pegylated liposomes formed large immune complexes with anti-mPEG antibodies. Both anti-PEG IgG and IgM antibodies accelerated the clearance of all pegylated compounds but anti-mPEG antibodies did not accelerate clearance of proteins with a single or branched PEG molecule. Pegylated liposomes were primarily taken up by Kupffer cells in the liver, but both anti-PEG and anti-mPEG antibodies directed uptake of a heavily pegylated protein to liver sinusoidal endothelial cells. Our results demonstrate that in contrast to anti-PEG antibodies, immune complex formation and drug clearance induced by anti-mPEG antibodies depends on pegylation architecture; compounds with a single or branched PEG molecule are unaffected by anti-mPEG antibodies but are increasingly affected as the number of PEG chain in a structure increases.

Treatment of eosinophilic otitis media with pegylated interferon-α 2a and 2b

OBJECTIVE/HYPOTHESIS

Eosinophilic otitis media (EOM) is a variant of chronic otitis media that is characterized by the development of thick mucoid middle ear effusion, adult onset bronchial asthma, sinonasal polyposis, and aspirin sensitivity. EOM is typically refractory to corticosteroid therapy and surgical intervention. Pegylated interferon (PEG-IFN) has effectively treated hypereosinophilic syndrome in clinical trials; however, the efficacy of this medication for EOM treatment remains undefined.

STUDY DESIGN

Retrospective, case series, tertiary academic center.

METHODS

A retrospective chart review was performed on EOM patients from 2008-2014. A total of 32 patients met the clinical criteria for EOM according to established diagnostic guidelines. Outcomes of all patients with severe, refractory EOM who initiated PEG-IFN therapy are reported.

RESULTS

Eight patients were treated with pegylated interferon-α 2a or 2b for refractory EOM. Half of the patients had significant side effects with interferon treatment. Three of these were able to continue at a reduced dosage without side effect reoccurrence, and one patient stopped the medication permanently. Four of eight (50%) patients had a complete clinical response with total resolution of otorrhea and normalization of middle ear mucosa, and were able to discontinue corticosteroid treatment. Two patients attempted to stop PEG-IFN therapy after prolonged symptom remission and had recurrent otorrhea. Both patients had symptom resolution after PEG-IFN reinitiation.

CONCLUSIONS

These data demonstrate that pegylated interferon-α 2a and 2b therapy may benefit patients with severe, refractory EOM. Further larger studies with long-term follow-up are required to validate these early but promising results.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:1208-1216, 2017.

Effect of Fuzheng Huayu capsule combined with Pegasys on genotype 1 hepatitis C fibrosis and cell apoptosis

The aim of the present study was to observe the effects of Fuzheng Huayu capsule combined with Pegasys (peginterferon α-2a) on hepatic fibrosis in rats and in the treatment of patients with genotype 1 hepatitis C and hepatic cirrhosis. A dimethylnitrosamine (DMN)-induced rat model of liver injury was established. Fuzheng Huayu capsule combined with Pegasys was administered to the rats and the DMN-induced hepatocyte apoptosis was observed. In addition, a total of 100 patients with genotype 1 hepatitis C and hepatic cirrhosis were treated by oral administration of Fuzheng Huayu capsule combined with Pegasys or with Pegasys alone. The therapeutic effect of Fuzheng Huayu capsule combined with Pegasys was analyzed. Following the oral administration of Fuzheng Huayu capsule combined with Pegasys to the DMN model rats, the expression of α-smooth muscle actin was found to be significantly reduced, hemopoietic stem cell apoptosis was increased and liver cell apoptosis was reduced. These indices were significantly different compared with those in the model group (P<0.05). Liver function and liver fibrosis were markedly recovered in hepatitis C patients with hepatic cirrhosis following treatment with the combination treatment compared with those in the patients treated with Pegasys alone (P<0.05). In conclusion, the combination of Fuzheng Huayu capsule with Pegasys inhibited liver fibrosis and cell apoptosis, and may be a novel therapeutic strategy for the treatment of patients with compensated cirrhosis due to hepatitis C. This study provides a method for the optimization of existing treatment strategies and for the establishment of potentially effective combination therapies.

The comparative efficacy and safety of peginterferon alpha-2a vs. 2b for the treatment of chronic HCV infection: a meta-analysis

BACKGROUND AND AIMS

Two types of peginterferon, alpha-2a (PEG-IFN-α2a) and 2b (PEG-IFN-α2b), are approved for the treatment of hepatitis C infection. Several high-quality studies have compared the efficacy of these two types of interferon, but it seems that any of these trials had inadequate statistical power on their own to find even a tiny difference between these two medicines. We pooled the available data in the literature to find any small difference between these two medicines.

METHODS

In a systematic review of the literature, randomized controlled trials comparing the use of PEG-α2a vs. 2b were assessed. The DerSimonian and Laird method was employed to run meta-analysis. The end points were virological responses.

RESULTS

In 7 randomized controlled trials, 3518 patients were randomized to receive PEG-IFN-α2a + ribavirin (n=1762) or PEG-IFN-α2b + ribavirin (n=1756). Early virological response (EVR), early treatment response (ETR), and sustained virological response (SVR) were greater for patients treated with PEG-IFN-α2a. Odds Ratios (ORs) were 1.38 (95% confidence interval [CI] 1.11-1.71), 1.67 (95% CI 1.24-2.24), and 1.38 (95% CI 1.02-1.88) respectively. In the subset of naïve patients with genotype 1/4 and 2, ORs of SVR were 1.38 (95% CI 1.02-1.88) and 4.06 (95% CI 1.67-9.86) respectively. PEG-IFN-α2a had significantly higher rate of neutropenia OR=1.50 (95% CI 1.25-1.79) but pooled OR for withdrawal rates was not significant [OR=0.78 (95% CI 0.47-1.29)].

CONCLUSIONS

PEG-IFN-α2a with similar safety is more effective than PEG-IFN-α2b. A longer duration of maximum serum concentration compared with PEG-IFN-α2b (168 vs. 48-72 h.) yields a greater SVR and higher neutropenia in PEG-IFN-α2a recipients.

Acute inflammatory demyelinating polyneuropathy associated with pegylated interferon α 2a therapy for chronic hepatitis C virus infection

The combination of pegylated interferon (Peg-IFN) and ribavirin is the standard of care for chronic hepatitis C virus (HCV) infection treatment. In general, common side effects related to this combination therapy are mild and are very well tolerated. However, peripheral neuropathy including demyelinating polyneuropathy related to Peg-IFN is extremely rare. We present the first case of an acute inflammatory demyelinating polyneuropathy (AIDP) associated with Peg-IFN-α 2a (Pegasys) after 16 wk of a combination therapy with Pegasys and ribavirin in a 65-year-old woman with chronic HCV infection. She developed tingling, numbness, and weakness of her upper and lower extremities and was hospitalized for acute neurological deficits. Her clinical course, neurological findings, an electromyogram (EMG), nerve conductions studies (NCS), muscle biopsy, and a sural nerve biopsy were all consistent with AIDP likely related to Pegasys use. The patient recovered completely with the use of intravenous immunoglobulin (IVIG) including physical therapy and neurological rehabilitation. It is very important that gastroenterologists and/or hepatologists recognize this rare neurological complication related to Peg-IFN treatment very early, since it requires a prompt discontinuation of therapy including an immediate referral to a neurologist for the confirmation of diagnosis, management, and the prevention of long-term neurological deficits.

Treatment of hepatitis C virus genotype 4 with peginterferon alfa-2a: Impact of bilharziasis and fibrosis stage

AIM: To evaluate pegylated interferon alpha2a (PegIFN-α2a) in Egyptian patients with HCV genotype 4, and the impact of pretreatment viral load, co-existent bilharziasis and histological liver changes on response rate.

METHODS: A total of 73 naïve patients (61 with history of bilharziasis) with compensated chronic HCV genotype 4 were enrolled into: group A (38 patients) who received 180 mg PegIFN-alpha2a subcutaneously once weekly for a year and group B (35 patients) received IFN alpha-2a 3 MU 3 times weekly. Ribavirin was added to each regimen at a dose of 1200 mg. Patients were followed for 72 wk and sustained response was assessed.

RESULTS: Significant improvement in both end of treatment response (ETR) (P < 0.002) and sustained response (SR) (P < 0.05) was noted with pegylated interferon, where ETR was achieved in 29 (76.3%) and 14 patients (40%) in both groups respectively, and 25 patients in group A (65.8%) and 9 (25.7%) in group B could retain negative viraemia by the end of follow up period. Sustained virological response (SVR) showed a significant negative correlation with age and positive correlation with pretreatment inflammation in patients receiving PegIFN. Viral clearance after 3 mo of therapy was associated with high incidence of ETR and SR (P < 0.001), but without significant difference between both forms of interferon. Significant improvement in response was achieved in patients with high grade fibrosis (grade 3 and 4) with PegIFN-α2a, where SR was seen in 5 out of 13 patients in group A, but none in group B. There was no significant difference in response between bilharzial and non-bilharzial patients in both groups. In terms of safety and tolerability, neutropenia was the predominant side effect; both drugs were comparable.

CONCLUSION: PegIFN-α2a combined with ribavirin results in improvement in sustained response in HCV genotype 4, irrespective of history of bilharzial infestation.