Structural and biological characterization of pegylated recombinant interferon alpha-2b and its therapeutic implications

The type I interferon alpha family consists of small proteins that have clinically important anti-infective and anti-tumor activity. Interferon alpha-2b (Intron A) combination therapy with ribavirin is the current standard of care for the treatment of chronic hepatitis C virus infection. A drawback to the therapy however, is the short serum half-life and rapid clearance of the interferon alpha protein. Schering-Plough has developed a semi-synthetic form of Intron A by attaching a 12-kDa mono-methoxy polyethylene glycol to the protein (PEG Intron) which fulfills the requirements of a long-acting interferon alpha protein while providing significant clinical benefits. A detailed physicochemical and biological characterization of PEG Intron revealed its composition of pegylated positional isomers and the specific anti-viral activity associated with each of them. Though pegylation appeared to decrease the specific activity of the interferon alpha-2b protein, the potency of PEG Intron, independent of protein concentration, was comparable to the Intron A standard at both the molecular and cellular level. Importantly, PEG Intron has demonstrated an enhanced pharmacokinetic profile in both animal and human studies. Recently, PEG Intron in combination with ribavirin has been shown to be very effective in reducing hepatitis C viral load and maintaining effective sustained viral suppression in patients. Because of the improved clinical benefits, it is anticipated that the PEG Intron plus ribavirin combination therapy will become the new standard of care for the treatment of chronic hepatitis C.     

48 weeks pegylated interferon alpha-2a is superior to 24 weeks of pegylated interferon alpha-2b in achieving hepatitis B e antigen seroconversion in chronic hepatitis B infection

BACKGROUND/AIM: Although 48-week therapy with pegylated-interferons has been shown to be effective for the treatment of chronic hepatitis B virus infection, the efficacy of a shorter duration of therapy with pegylated interferons is unknown. METHOD: We reviewed 53 hepatitis B e antigen positive Chinese patients treated with 48 weeks of pegylated interferon alpha-2a or 24 weeks of pegylated interferon alpha-2b. Sustained virological response was defined as hepatitis B e antigen seroconversion and hepatitis B virus DNA <10(5) copies/mL at week 72. RESULTS: Twenty-nine patients were treated with 48 weeks of pegylated-interferon-alpha-2a and 24 patients with 24 weeks of pegylated-interferon-alpha-2b. At the end-of-therapy, hepatitis B e antigen seroconversion and hepatitis B virus DNA <10(5) copies/mL were similar between the two groups of patients [9/29 (31.0%) vs. 2/24 (8.3%), respectively, P = 0.09]. At week 72, 10 of the 29 patients (34.5%) treated with 48 weeks of pegylated-interferon-alpha-2a compared with two of the 24 patients (8.3%) treated with 24 weeks of pegylated-interferon-alpha-2b had sustained virological response (P = 0.04). By logistic analysis, 48 weeks of pegylated-interferon-alpha-2a was independently associated with sustained virological response (P = 0.04 adjusted hazards-ratio 9.37). CONCLUSION: Further studies are required to determine the optimal duration of therapy with pegylated interferons in chronic hepatitis B.     

Rosacea fulminans associated with pegylated interferon alpha-2B and ribavirin therapy

Rosacea fulminans is characterized by the sudden onset of large, coalescing nodules and draining sinuses on the face. A few reports have linked medications to this condition, but none have described the onset of rosacea fulminans with pegylated interferon or ribavirin therapy. We report a patient who presented with rosacea fulminans after initiation of therapy for Hepatitis C.     

Pharmacokinetics of interferon alpha-2b in healthy volunteers

In a three-way crossover design, 12 healthy male volunteers received 5 X 10(6) IU/m2 body surface area interferon alpha-2b(IFN alpha-2b) by intravenous (IV) infusion over 30 minutes, intramuscular (IM) injections, and subcutaneous (SC) injections. Blood and urine samples were collected at specified times, and analysis of IFN alpha-2b concentrations was performed by immunoradiometric assay. "Flulike" symptoms were the most frequently reported adverse experiences and were independent of the route of administration. After a 30-minute IV infusion, IFN alpha-2b disappeared rapidly from serum, with distribution and elimination phase half-lives of 0.1 hour and 1.7 hours, respectively. Interferon alpha-2b was absorbed slowly after IM and SC administration, with similar absorption half-lives of 5.8 and 5.5 hours, respectively. The observed maximal concentrations after IM and SC administration were 42.1 IU/mL at six hours and 45.8 IU/mL at eight hours, respectively. Interferon alpha-2b was eliminated with half-lives of 2.2 hours after IM administration and 2.9 hours after SC administration. The areas under the serum concentration-time curves for the SC and IM doses were higher than those obtained for the IV infusion. Measurable amounts of IFN alpha-2b were not found in urine regardless of the route of administration.     

Development of interferon alpha-2b microspheres with constant release

Interferon alpha-2b (IFNα-2b) is an important immune regulator used widely in clinic. However, frequent subcutaneous injection and substantial toxicity decrease patients' compliance. So, drug delivery with more precisely controlled drug release is urgent for IFNα-2b. Microsphere is a promising sustained drug delivery system, which has been studied widely for delivery of proteins. However, it was found difficult to keep proteins' activity and guarantee complete release. In this study, we solidified IFNα-2b as microparticles firstly by co-lyophilizing it with gelatin and ZnSO(4). Microspheres were then prepared. The preparing procedure and formulation were optimized with encapsulation efficiency and in vitro release as main parameters. Finally, the microspheres were prepared by S/O/W method with microparticle size about 5 μm and PEGT/PBT-PLGA (9:1, w/w) as matrix material. The diameter of microspheres was 28.94 μm, the encapsulation efficiency was 86.01%, the burst release was 16.69%, the cumulative release was 83.06% at 23th day, and IFNα-2b was released from microspheres with a zero-order profile. These microspheres also demonstrated sustained and steady release for about 13 days in rats. In conclusion, the procedure and formulation used in this study were supposed to be successful to keep IFNα-2b active and released constantly and completely.     

聚乙二醇干扰素α-2a抗病毒过程中cccDNA的变化

目的探讨聚乙二醇干扰素α-2a对慢性乙型肝炎患者肝组织中共价闭合环状DNA(cccDNA)的影响。方法将76例慢性乙型肝炎患者分为对照组和治疗组,对照组应用普通干扰素,治疗组给予聚乙二醇干扰素α-2a治疗48周,观察肝组织中乙肝病毒(HBV)cccDNA检出率和含量,肝组织和血清HBV DNA病毒含量及血清ALT、AST和总胆红素(TBIL)的含量。结果 2组治疗后HBV cccDNA检出率和含量均明显降低(P<0.05),肝组织和血清HBV DNA病毒含量及血清ALT、AST和TBIL的含量均明显降低(P<0.05),治疗组治疗后降低量更显著(P<0.05)。结论聚乙二醇干扰素α-2a对慢性乙型肝炎患者肝组织中cccDNA的清除疗效显著优于普通干扰素。     

干扰素α-2b治疗毛细支气管炎的用药途径及疗效分析

目的：现察干扰素α-2b不同用药途径治疗毛细支气管炎的疗效。方法：120例随机分成对照组、干扰素α-2b雾化组和肌注组各40例，进行临床疗效比较。结果：雾化组与肌注组咳嗽、喘憋、胸部X线片等恢复时间均快于对照组，而以雾化组疗效最佳。结论：干扰素α-2b氧气雾化吸入治疗毛细支气管炎疗效更佳。     

The safety of pegylated interferon alpha-2b in the treatment of chronic hepatitis B: predictive factors for dose reduction and treatment discontinuation

BACKGROUND: Treatment with interferon-alpha has been shown to be effective in one-third of hepatitis B e antigen-positive chronic hepatitis B patients, but is clinically associated with relevant adverse events. AIM: To investigate the safety of pegylated interferon alpha-2b in 300 hepatitis B e antigen-positive patients with compensated liver disease. METHODS: Patients were treated with pegylated interferon alpha-2b for 52 weeks combined with either lamivudine 100 mg/day or placebo. Pegylated interferon alpha-2b was administered for 100 microg once a week for 32 weeks; thereafter, the dose was reduced to 50 microg once a week. Adverse events and their effect on study medication were reported at monthly visits in a standardized way. RESULTS: The most frequently reported side-effects were flu-like syndrome (68%), headache (40%), fatigue (39%), myalgia (29%) and local reaction at the injection site (29%). These symptoms typically occurred within the first month of therapy and subsided during the course of therapy. Neutropenia and thrombocytopenia induced by pegylated interferon alpha-2b increased the risk of infections and bleeding complications, but these complications were rare and mild. The frequency of all side-effects was not different between patients treated with pegylated interferon alpha-2b combined with lamivudine or placebo. In 69 (22%) patients the dose of pegylated interferon alpha-2b was reduced prematurely. Of these dose reductions, 36 (52%) were because of neutropenia. Therapy was discontinued in 28 (8%) patients. The most frequent reasons for early discontinuation were psychiatric side-effects (depression, psychosis) and flu-like symptoms. Multivariate Cox regression analysis showed that low neutrophil count at baseline and cirrhosis were independent predictors of dose reduction or therapy discontinuation. CONCLUSION: We conclude that in patients with chronic hepatitis B and compensated liver disease prolonged pegylated interferon alpha-2b therapy is safe, and that pre-existent cirrhosis and neutropenia are the most important predictors of dose reduction or early treatment discontinuation.     

Multivesicular liposome formulations for the sustained delivery of interferon α-2b

AIM: To develop and optimize a sustained release multivesicular liposome (MVL) formulation of interferon (IFN) alpha-2b. METHODS: IFN alpha-2b MVL were prepared using a typical double-emulsion procedure. The sustained release effects of IFN alpha-2b MVL were investigated by monitoring the blood IFN alpha-2b concentration using an enzyme-linked immunosorbent assay test after subcutaneous administration to healthy mice. RESULTS: IFN alpha-2b was successfully encapsulated in MVL with high efficiency, and the integrity of encapsulated protein was maintained. After subcutaneous injection, the MVL slowly released IFN alpha-2b into systemic circulation in a sustained manner. The estimated serum half-life of IFN alpha-2b was approximately 30 h. In addition, varying the size of the MVL preparations could further modify the in vivo release profile. CONCLUSION: IFN alpha-2b MVL may be a useful sustained release formulation in the clinical treatment of viral diseases.     

Tolerability of interferon alpha-2b, a possible new treatment of active Crohn's disease

Background and aims: Due to the need for new principles for the treatment of Crohn's disease and due to the documented immunomodulatory effects of interferon alpha, the tolerability and effect(s) of interferon alpha-2b (Introna) in active Crohn's disease were examined in a pilot study. Methods: Five patients with active Crohn's disease (activity index (CDAI) scores of 235–517), were treated with interferon alpha-2b for 12 weeks. Results: All patients tolerated the treatment, but developed influenza-like symptoms, which were fully controlled by paracetamol. Two patients obtained partial remission with a decline in activity index scores of 39% and 50%. The activity of 2′, 5′-oligoadenylate synthetase, which together with two other interferon-induced proteins, neopterin and β₂-microglobulin were increased during treatment, indicated clearly an in vivo uptake of interferon. Sedimentation rate, C-reactive protein, orosomucoid, albumin, specific inflammatory markers: soluble interleukin-2 α-receptors (sIL-2R) and intercellular adhesion molecule-1 (ICAM-1) did not show any changes before or after treatment. Conclusion: Future multicentre investigations are required to evaluate the clinical effect of interferon alpha-2b treatment in active Crohn's disease.     

聚乙二醇干扰素α-2b或联合阿德福韦酯治疗慢性乙型肝炎患者的外周血象变化

目的 观察聚乙二醇干扰素α-2b或联合阿德福韦酯治疗HBeAg阳性慢性乙型肝炎（CHB）患者的外周血象变化。方法 收集2012年6月至2013年9月安徽医科大学第一附属医院、安徽医科大学附属巢湖医院、安徽中医药大学第一附属医院、阜阳市第二人民医院、皖南医学院附属弋矶山医院等10家医院就诊的HBeAg阳性的CHB患者102例,签署知情同意书,随机分为单药组（51例）和联合组（51例）,治疗48周,停药后再随访24周。通过检测受试者基线（0周）、4周、8周、12周、24周、36周、48周、60周、72周的外周血象变化,观察2种治疗方案对外周血象的影响。结果 治疗48周时,联合组患者的HBV DNA转阴率（76.60%）、ALT复常率（70.21%）高于单药组,差异有统计学意义（P<0.05）。不同时间点间白细胞（WBC）、中性粒细胞（N）、淋巴细胞（L）、红细胞（RBC）、血红蛋白（Hb）、血小板（PLT）变化不同,差异有统计学意义（P<0.05）;Hb、PLT与组别之间有交互作用,差异有统计学意义（P<0.05）。单药组对N的影响较联合组更大,差异有统计学意义（P<0.05）。两组患者治疗期间WBC、N、L、PLT均有不同程度的下降,在第0～4周下降最明显,治疗期间趋于稳定,停药后很快恢复正常。结论 联合治疗有一定优势,患者治疗期间外周血WBC、N、L、RBC都具有类似的下降趋势,但联合治疗对Hb、PLT有影响,呈可逆性,停药后很快恢复,治疗期间应严密监测。     

Bioequivalence of two recombinant interferon alpha-2b liquid formulations in healthy male volunteers

OBJECTIVE: Interferon (IFN) alpha-2b is a protein with antiviral, antiproliferative and immunoregulatory properties that is approved for several clinical indications. A new liquid, albumin-free, IFNalpha-2b formulation has recently been developed. This study aimed to evaluate the equivalence of the pharmacokinetic, pharmacodynamic and safety properties of the new formulation with a reference one in healthy male volunteers. METHODS: A randomised, crossover, double-blind study with a 3-week washout period was performed in which Heberon Alfa R (formulation A) and Viraferon (formulation B) were compared. A single 20 x 10(6) IU IFNalpha-2b dose was administered subcutaneously to 14 apparently healthy male subjects. Serum IFN level was measured over 48 hours by enzyme immunoassay (EIA) and by antiviral activity titration. Clinical and laboratory variables were determined, as were pharmacodynamic and safety criteria. RESULTS: Groups were homogeneous with regard to all demographic and baseline variables. Pharmacokinetic comparison by EIA did not show differences between the formulations: area under the curve (AUC) 2572 versus 2561 ng x h/L, maximum plasma concentration (Cmax) 318 versus 354 ng/L, time to Cmax (tmax) 8.2 versus 8.5 h, elimination half-life (t(1/2)) 5.87 versus 6.08 h, terminal elimination rate (lambda) 0.122 versus 0.118 h(-1), and mean residence time (MRT) 10.9 versus 12.0 h for formulations A and B, respectively. The differences never reached 20%, which is the clinically significant threshold. The 90% confidence interval of the ratio between them was in all cases within the 0.8, 1.25 range. The two formulations were clinically equivalent with regard to serum IFN antiviral activity titration (0.8, 1.25 criterion) regarding their pharmacokinetic parameters. There were no significant differences with respect to the pharmacodynamic variables: serum beta2-microglobulin and temperature increase. Heart rate and blood pressure changes did not differ either. Both products provoked similar haematological count decreases and had similar safety profiles. The most frequent adverse reactions were fever, tachycardia, headache and arthralgias. CONCLUSION: The overall analysis strongly suggests the bioequivalence of these two products.     

聚乙二醇干扰素α-2a联合阿德福韦酯治疗HBeAg阳性慢性乙型肝炎疗效观察

目的：探讨聚乙二醇干扰素α-2a （Peg-IFNα-2a）联合阿德福韦酯治疗HBeAg阳性慢性乙型肝炎（CHB）疗效的观察。方法147例慢性乙型肝炎患者分为三组,阿德福韦酯组、聚乙二醇干扰素α-2a组及联合组,对比分析在治疗24、36、48周时各组HBV-DNA转阴率、转氨酶复常率、HBeAg转阴率、HBeAg/HBeAb转换率和HBsAg转阴率差别。结果在治疗第24周,联合组患者HBV-DNA下降幅度log（3.56±1.16）明显高于另两组（P＜0.05）。在36、48周时,联合组在转氨酶复常率、HBsAg转阴率、HBeAg/HBeAb转换率和HBV-DNA转阴率对比另两组差异有统计意义（P＜0.05）。结论聚乙二醇干扰素（Peg-IFNα）联合阿德福韦酯治疗HBeAg阳性慢性乙型肝炎优于单一用药。     

Cost effectiveness of peginterferon alpha-2a plus ribavirin versus interferon alpha-2b plus ribavirin as initial therapy for treatment-naive chronic hepatitis C

INTRODUCTION: In adults with previously untreated chronic hepatitis C (CHC), the combination of peginterferon alpha-2a plus ribavirin produces a higher rate of sustained virological response (SVR) than interferon alpha-2b plus ribavirin, but it is still unproven whether this increase is cost effective. The objective of this study was to determine if the gain in SVR with peginterferon alpha-2a plus ribavirin is worth the incremental cost. METHODS: We constructed a Markov model of disease progression in which cohorts of patients received peginterferon alpha-2a plus ribavirin or interferon alpha-2b plus ribavirin for 48 weeks (hepatitis C virus [HCV] genotype 1 and non-1 patients with fibrosis) or 24 weeks (genotype non-1 patients without fibrosis), and were followed for their expected lifetimes. The reference patient was a 45-year-old male with CHC without cirrhosis. The SVRs with peginterferon alpha-2a plus ribavirin and interferon alpha-2b plus ribavirin used to populate the model were 46% and 36% for patients infected with HCV genotype 1 and 76% and 61% for patients infected with HCV non-1 genotypes, respectively. QOL and costs for each health state were based on literature estimates and on Italian treatment patterns. Costs were in 2002 euros and benefits were discounted at 3%. Sensitivity analyses on key clinical and economic parameters were performed. The analysis was reported from the perspective of the Italian National Health Service. RESULTS: In patients infected with HCV genotype 1, peginterferon alpha-2a plus ribavirin increased life-years (LYs) by 0.78 years and QALYs by 0.67 years, compared with interferon alpha-2b and ribavirin. The incremental cost per LY and QALY gained was euro9433 and euro10 894, respectively. In patients infected with HCV non-1 genotypes, peginterferon alpha-2a plus ribavirin increased LYs by 1.17 and QALY by 1.01 years, compared with interferon alpha-2b plus ribavirin. The incremental cost per LY and QALY gained was euro3261 and euro3766, respectively. Using genotype distribution estimates, the weighted average ICER for all genotypes was euro6811 per LY gained and euro7865 per QALY gained. CONCLUSION: Our model suggests that peginterferon alpha-2a plus ribavirin is cost effective compared with conventional interferon alpha-2b plus ribavirin for treatment of naive adults with CHC, regardless of HCV genotype, under a wide range of assumptions regarding treatment effectiveness and costs.     

重组人干扰素a-2b治疗宫颈上皮内瘤变远期随访

目的研究干扰素a-2b(IFN-a-2b)治疗宫颈上皮内瘤样病变(CIN)的长期效果。方法对2005年5月～2010年4月期间14例诊断为CINⅠ和CINⅡ的患者均使用IFN-a-2b治疗,并且随访5年,用药第1、2年,每3个月实施1次巴氏涂片和阴道镜检,后3年,每6个月实施1次相同的检查。结果 10例完全清除了人乳头瘤病毒(HPV)所致的CIN,4例部分有效,即较低的CIN和(或)HPV清除率,4例无效。3例CINⅠ复发,复发率为30%,4例短期疗效为部分有效病例中3例长期疗效显示完全清除,CINⅠ和CINⅡ患者总的IFN-a-2b治愈率为55.55%。结论 IFN-a-2b的免疫调节治疗法有较好的长期疗效。     

Interleukin-15 biology and its therapeutic implications in cancer

Cancer immunotherapy is designed to stimulate the immune system to reject and destroy tumors. Recently, interleukin-15 (IL-15), a member of the four α-helix bundle family of cytokines, has emerged as a candidate immunomodulator for the treatment of cancer. IL-15 acts through its specific receptor, IL-15Rα, which is expressed on antigen-presenting dendritic cells, monocytes and macrophages. IL-15 exhibits broad activity and induces the differentiation and proliferation of T, B and natural killer (NK) cells. It also enhances the cytolytic activity of CD8(+) T cells and induces long-lasting antigen-experienced CD8(+)CD44(hi) memory T cells. IL-15 stimulates differentiation and immunoglobulin synthesis by B cells and induces maturation of dendritic cells. It does not stimulate immunosuppressive T regulatory cells (Tregs). Thus, boosting IL-15 activity could enhance innate and specific immunity and fight tumors. Here we review aspects of IL-15 biology that make it a promising agent for anticancer therapy. We also discuss preclinical models in which IL-15 has demonstrated antitumor activity and highlight ongoing clinical trials of IL-15 in patients with cancer and HIV infection.     

聚乙二醇干扰素α-1b对荷ACHN肿瘤裸鼠的治疗作用

目的：比较不同剂量聚乙二醇干扰素α-1b（PEG IFN α-1b）对荷人肾腺癌细胞（ACHN）瘤裸鼠的治疗效果。方法：制备荷ACHN瘤鼠模型，分溶剂对照及PEG IFNα-1b 50，150和300μg组。给药组每只鼠每周1次皮下注射不同剂量的PEG IFN α-1b，溶剂对照组注射等体积溶剂，连续5周给药。每周1次测量肿瘤体积和动物体重，第5周末取肿瘤测其体积与重量。结果：第5周末各组肿瘤体积分别为给药前的258．9％，152．0％，95．5％和67．5％，三个给药组按肿瘤重量计算肿瘤抑制率分别为28．91％，37．68％和49．53％（P〈0．05）。结论：每周1次，连续5周皮下注射PEG IFN α-1b可以显著抑制ACHN荷瘤裸鼠肿瘤的生长，其中300μg剂量组的效果最好。     

A randomized trial of high-dose interferon alpha-2b, with or without ribavirin, in chronic hepatitis C patients who have not responded to standard dose interferon

BACKGROUND: Conventional interferon monotherapy fails to achieve virological clearance in most hepatitis C-infected patients. The use of high-dose induction regimens may improve the initial clearance of virus, while the addition of ribavirin appears to improve the rates of sustained response once clearance is achieved. AIM: To compare the efficacy and safety of re-treatment with an induction regimen of high-dose interferon alpha-2b, with or without ribavirin, in chronic hepatitis C patients who have not responded to standard dose interferon monotherapy. METHODS: Previous virological non-responders to standard dose interferon (3-5 MU three times weekly for > or = 12 weeks) were randomized to receive, unblind, either 10 MU interferon alpha-2b daily for 10 days, then 5 MU daily for 74 days, then 5 MU three times weekly for 24 weeks (total 36 weeks) (group A), or the above regimen with the addition of ribavirin, 1000-1200 mg/day, at day 11 (group B). All patients were followed up for 24 weeks after completion of therapy. RESULTS: End of treatment virological response was noted in one of 10 (10%) patients in group A and in eight of 15 (54%) patients in group B (P=0.04). The sole end treatment responder in group A and three in group B relapsed on follow-up. The apparent improvement in response in group B compared to group A nearly reached statistical significance (group B 5/15 vs. group A 0/10; P=0.06). CONCLUSIONS: In this small pilot study, a 36-week high-dose induction interferon monotherapy protocol did not yield sustained responses in previous non-responders to standard dose interferon. However, the same regimen with ribavirin yielded a 33% sustained response rate, nearly reaching statistical significance. The therapy was well tolerated, despite the higher doses of interferon used and the addition of ribavirin. High-dose interferon with ribavirin appears to be a therapeutic option for non-responders to conventional interferon monotherapy.