Recombinant interferon-beta-1a: a review of its therapeutic efficacy in relapsing-remitting multiple sclerosis

Sustained in vitro interferon-beta release and in vivo toxicity of PLGA and PEG-PLGA nanoparticles

Interferon-beta-1a (IFN-β-1a) can diminish the symptoms of relapsing-remitting multiple sclerosis. Herein, we prepared sustained drug delivery IFN-β-1a-loaded nanoparticles by a double emulsion solvent evaporation method. Bovine serum albumin (BSA) model drug was used to optimize the preparation of nanoparticles composed of four types of poly(lactic-co-glycolic acid) (PLGA) polymers and two pegylated PLGA (PEG-PLGA) polymers. Via optimization, selected PLGA and PEG-PLGA polymers were able to entrap IFN-β-1a with high encapsulation efficiency (>95%) and low size (145 nm and 163 nm, respectively). In vitro release kinetics of BSA and IFN-β showed similar tendency for PLGA and PEG-PLGA nanoparticles, respectively. Although the drug loaded nanoparticles did not show toxicity in hepatocyte cells, mild toxic effects such as pale kidney and pyelectasis were observed in the in vivo studies.

Subcutaneous recombinant interferon-β-1a (Rebif®): a review of its use in the treatment of relapsing multiple sclerosis

Subcutaneous recombinant interferon-β-1a (SC IFNβ-1a) [Rebif®] is indicated as monotherapy for the prevention of relapses and progression of physical disability in patients with relapsing multiple sclerosis (MS). This article reviews the efficacy and tolerability of SC IFNβ-1a in this indication, with further discussion of its pharmacological properties and pertinent pharmacoeconomic studies. SC IFNβ-1a efficacy and tolerability were evaluated in randomized, double-blind, multinational trials in patients with relapsing-remitting MS (RRMS). Its efficacy was demonstrated in the 2-year PRISMS trial, as SC IFNβ-1a 22 or 44 μg three times weekly (tiw) significantly reduced relapse rates, with an ≈30% relative risk reduction compared with placebo. SC IFNβ-1a was also associated with significantly delayed progression of disability, and lower disease activity according to MRI, relative to placebo. In the 24-week EVIDENCE trial, a significantly higher proportion of SC IFNβ-1a 44 μg tiw than intramuscular IFNβ-1a (Avonex®) 30 μg once weekly recipients remained relapse free. A serum-free formulation of SC IFNβ-1a 44 μg tiw was more efficacious than placebo in preventing the development of brain lesions in the 16-week IMPROVE trial. In the 96-week REGARD trial, the efficacy of SC IFNβ-1a 44 μg tiw was not significantly different to that of glatiramer acetate for clinical endpoints, although it was associated with reduced development of brain lesions compared with glatiramer acetate, according to some MRI endpoints. In the 36-month CAMMS223 trial, alemtuzumab led to significantly lower relapse rates and risk of developing sustained disability than SC IFNβ-1a 44 μg tiw, and was generally more efficacious according to other clinical and MRI endpoints. Across trials, influenza-like symptoms, injection-site reactions, haematological disturbances and hepatic enzyme abnormalities were the most common treatment-emergent adverse events occurring with SC IFNβ-1a. In the PRISMS trial, SC IFNβ-1a 22 and 44 μg tiw recipients had more injection-site reactions than placebo recipients and, at the higher dosage, haematological disturbances and increases in ALT levels were also significantly more frequent than with placebo. Pooled data from clinical trials and postmarketing surveillance indicate that haematological and hepatic adverse events are generally asymptomatic and rarely result in treatment discontinuation. Nevertheless, some cases of serious hepatic complications have been reported. In cost-utility studies, first-line therapies for RRMS, including SC IFNβ-1a, all exceeded commonly accepted US thresholds for incremental cost per quality-adjusted life-years gained relative to symptomatic treatment. However, because of patient need and the difficulty in adequately assessing cost utility in a gradually progressive disease, these agents have been made available to many patients worldwide through special access programmes. Overall, SC IFNβ-1a has a favourable risk-benefit ratio and is a valuable first-line treatment option for patients with relapsing MS.

Review of the clinical evidence for interferon beta 1a (Rebif) in the treatment of multiple sclerosis

Interferon (INF) beta 1a 22 or 44 mug (Rebif((R))) administered s.c. 3 times a week (t.i.w) is a well established immunomodulating treatment for relapsing remitting multiple sclerosis (RRMS). This review focuses on its mechanisms of action, evidence of efficacy, safety, and tolerability. Several pharmacodynamic properties explain the immunomodulatory actions of INF beta 1a 22 or 44 mug s.c. t.i.w. Pivotal trials and post-marketing studies proved that the drug is effective in reducing disease activity and likely in slowing disease progression. Head-to-head comparative studies with other marketed INFs beta in RRMS suggested a better therapeutic response associated with higher doses and frequency of administration of Rebif((R)). Additional evidence indicated a beneficial effect of INF beta 1a in patients with clinically isolated syndromes (CIS) suggestive of MS, as treatment reduced time to conversion to clinically definite (CD) disease. Further, although the drug did not prove to slow time to progression there were benefits on relapse- and MRI-related secondary outcome measures in secondary progressive (SP) MS. Pivotal trials, their cross-over extensions, and post-marketing studies consistently showed that INF beta 1a 22 or 44 mug s.c. t.i.w. is safe and well tolerated, as adverse drug reactions are usually mild and manageable.

[Subcutaneous interferon-beta-1a in the treatment of multiple sclerosis]

During the last 10 years recombinant interferon-beta-1a administered subcutaneously has been the subject of several clinical trials in relapsing remitting multiple sclerosis (RRMS), in secondary progressive MS (SPMS), as well as in clinically isolated syndromes. All of them met the criteria of evidence level class I. Consistent evidence for moderate immunomodulatory effects on clinical parameters of disease activity was gained, and even higher efficacy of IFN-beta-1a sc. on MRI activity of multiple sclerosis was proven. Indirect evidence confirmed the hypothesis of a dose-response curve for IFN-beta-1a formulations in MS. The higher efficacy of IFN-beta-1a 44 microg sc. TIW, however, also includes more adverse events such as injection site reactions, flu-like symptoms and a moderate immunogenicity. Current evidence does not allow a recommendation of IFN-beta-1a sc. as most effective first line therapy, because also the individual patient's choice in the route of administration and long-term effects of neutralizing antibodies to IFN-beta-1a sc. must be taken into account. In the long-term, IFN-beta-1a showed a beneficial safety-tolerability profile with 50 % of patients sticking to the initial immunomodulatory treatment. There were no teratogenic effects, IFN-beta-1a sc. did not enhance depressive symptoms. Data on inhibition of the progression of disease, however, remained inconclusive. Probable beneficial effects of IFN-beta-1a sc. on cognitive function or "chronic fatigue" have not been investigated yet.

Subcutaneous interferon-beta-1a : new formulation

The new formulation of subcutaneous interferon-beta-1a was developed without serum-derived components with the aim of improving immunogenicity and injection tolerability in patients with relapsing forms of multiple sclerosis (MS). In a prospectively defined interim analysis at 48 weeks of an ongoing, single-arm, phase IIIb trial, 13.9% of MS patients receiving the new formulation of subcutaneous interferon-beta-1a 44 microg three times weekly had developed neutralising antibodies (NAbs). In the EVIDENCE trial, which served as an historical control, 24.4% of patients receiving the same dosage of the current formulation had developed NAbs at 48 weeks. The new formulation demonstrated similar pharmacokinetic activity to that of the current formulation in a phase I, double-blind, placebo-controlled study in healthy volunteers. About two-thirds of patients with MS who received the new formulation of subcutaneous interferon-beta-1a were relapse free in the interim, 48-week analysis of the single-arm trial; this is similar to results for the current formulation from historical data. A comparison of results from the interim, 48-week analysis with historical-control data from the EVIDENCE trial indicates that the new formulation of interferon-beta-1a may be associated with a lower incidence of injection-site reactions and a higher incidence of influenza-like symptoms than the current formulation. Adverse events associated with the new formulation were mostly mild to moderate in severity

Mitoxantrone: a review of its use in multiple sclerosis

Mitoxantrone (Novantrone), a synthetic anthracenedione derivative, is an antineoplastic, immunomodulatory agent. Its presumed mechanism of action in patients with multiple sclerosis (MS) is via immunomodulatory mechanisms, although these remain to be fully elucidated. Intravenous mitoxantrone treatment improved neurological disability and delayed progression of MS in patients with worsening relapsing-remitting (RR) [also termed progressive-relapsing (PR) MS] or secondary-progressive (SP) disease. In a pivotal randomised, double-blind, multicentre trial, mitoxantrone 12 mg/m(2) administered once every 3 months for 2 years provided significant improvements in neurological disability ratings, including Kurtzke Expanded Disability Status Scale (EDSS), Ambulatory Index (AI) and Standardised Neurological Status (SNS) scores, compared with placebo. The drug also significantly reduced the mean number of corticosteroid-treated relapses and prolonged the time to the first treated relapse, with the beneficial effects on disease progression supported by magnetic resonance imaging. Post hoc analyses suggest that the benefits associated with mitoxantrone treatment may be sustained for at least 12 months after cessation of treatment, mean changes from baseline at 36 months in EDSS, AI and SNS scores of 0.10, 0.61 and 0.19, respectively, in the mitoxantrone group versus 0.46, 1.13 and 3.38 with placebo. Concomitant intravenous mitoxantrone 20mg plus intravenous methylprednisolone 1g once every month for 6 months was more effective than intravenous methylprednisolone monotherapy in preventing the development of new gadolinium-enhanced lesions in patients with very active RRMS or SPMS. The drug was generally well tolerated in patients with MS. Adverse events were generally mild to moderate in severity and usually resolved upon discontinuation of treatment or with appropriate pharmacotherapy. At the recommended dosage, mitoxantrone appears to have a low potential to cause cardiotoxicity. In conclusion, intravenous mitoxantrone reduces the relapse rate and slows progression of the disease in patients with worsening RRMS, PRMS or SPMS; thus providing a new option for the management of these patients. The drug was generally well tolerated at the recommended dosage, although potential cardiotoxicity limits the total cumulative dose to 140 mg/m(2). Further studies are warranted to determine which patients with worsening RRMS, PRMS or SPMS are most likely to benefit from mitoxantrone treatment and to more fully define the long-term safety and tolerability of mitoxantrone, including the use of concomitant cardioprotectants to extend the therapeutic lifespan of the drug. Pharmacodynamic Profile. Mitoxantrone, a synthetic anthracenedione derivative, is an established cytotoxic, antineoplastic agent. Its presumed mechanism of action in multiple sclerosis (MS) is immunosuppression. In antineoplastic studies, the drug showed several immunomodulatory effects, inducing macrophage-mediated suppression of B-cell, T-helper and T-cytotoxic lymphocyte function. Currently, the pharmacodynamic properties of mitoxantrone have not been investigated to any extent in patients with MS. In one study, 6 months' treatment with intravenous mitoxantrone generally had no effect on the distribution of cytokine-positive peripheral blood monocyte cells in patients with MS. In an animal model of the disease, mitoxantrone suppressed the development and progression of both actively and passively induced acute experimental allergic encephalomyelitis (EAE). It appeared to be 10-20 times more effective than cyclophosphamide in the suppression of EAE. Moreover, mitoxantrone approximately doubled the mean time to onset of EAE versus control animals (279 vs 148 days after immunisation; p < 0.00005). In vitro, mitoxantrone 10 and 100 micro g/L inhibited myelin degradation by leucocytes and peritoneal macrophages derived from mice with acute EAE by approximately 60% and 100%. Pharmacokinetic Profile. Currently, there are no published pharmacokinetic data for intravenous mitoxantrone in pitoxantrone in patients with MS, paediatric patients or in those with renal impairment. All studies, to date, have been in patients with cancer receiving a single, approximately 30-minute intravenous infusion of mitoxantrone 5-14 mg/m(2). The drug exhibits triexponential pharmacokinetics, with a rapid initial distribution (alpha) phase, an intermediate distribution (beta) phase and a much slower elimination (gamma) phase. The mean half-life of the alpha phase appears to be 6-12 minutes and that of the beta phase 1.1-3.1 hours. Mitoxantrone has a high affinity for tissue, with a volume of distribution of up to 2248 L/m(2). Mitoxantrone persists for prolonged periods in tissues and was detectable in autopsy tissue from patients who last received the drug up to 272 days before death. At concentrations of 10-10000 ng/mL, the drug was 70-80 % bound to plasma proteins in dogs. Elimination of mitoxantrone occurs predominantly through biliary excretion and may be impaired in patients with hepatic dysfunction or third space abnormalities (e.g. ascites). The mean terminal elimination half-life of mitoxantrone ranged from 23 hours to 215 hours. Renal clearance accounts for 10 % of the total clearance of the drug. Total clearance of mitoxantrone ranged from 13 to 34.2 L/h/m(2) and renal clearance from 0.9 to 2.7 L/h/m(2). The drug appears to have a low potential for interaction with other concomitantly administered agents. Therapeutic Efficacy. Intravenous mitoxantrone (infusion of > or = 5 minutes), either as monotherapy or in combination with intravenous methylprednisolone, delayed the progression of the disease in patients with secondary-progressive (SP) or worsening relapsing-remitting (RR) MS (the latter is also termed progressive-relapsing MS) in comparative, randomised, multicentre trials. In a double-blind, monotherapy trial (Mitoxantrone In Multiple Sclerosis [MIMS] trial), mitoxantrone 12 mg/m(2) (n = 60) once every 3 months for 2 years significantly improved neurological disability relative to placebo (n = 64), as assessed by changes in mean Kurtzke Expanded Disability Status Scale (EDSS) score, mean Ambulatory Index (AI) score and mean Standardised Neurological Status (SNS) score. The drug also significantly reduced the mean number of corticosteroid-treated relapses per patient and prolonged the time to the first treated relapse. A Wei-Lachin multivariate analysis of these five efficacy variables indicated that the global difference between the two treatment groups was 0.30 (p < 0.0001). Mitroxantrone was also more effective than placebo according to secondary endpoints in this study, with fewer mitoxantrone recipients experiencing a relapse, a deterioration of > or =1 EDSS point or a confirmed deterioration in EDSS score over a 3-month period. Mitoxantrone recipients also showed less deterioration in quality-of-life ratings and had fewer hospital admissions, whereas more placebo recipients had new gadolinium-enhanced lesions at study end (the latter parameter was assessed using magnetic resonance imaging [MRI] in a subgroup of 110 patients, including 40 patients who received an exploratory 5 mg/m(2) dose). Furthermore, post hoc analyses indicated that the beneficial effects of mitoxantrone treatment on EDSS, SNS and AI scores were sustained for at least 12 months after cessation of treatment, with mean changes from baseline at 36 months in EDSS, AI and SNS scores of 0.10, 0.61 and 0.19, respectively, in the mitoxantrone group versus 0.46, 1.13 and 3.38 with placebo. Preliminary data from a cost-minimisation analysis based on results from the MIMS trial indicated that approximately half of the cost of mitoxantrone was offset by cost savings in other areas associated with the treatment of MS (direct and indirect major costs), with a total annual incremental cost for mitoxantrone of dollar 1661 per patient. Combination therapy once-monthly with intravenous mitoxantrone 20mg plus intravenous methylprednisolone 1g was more effective than intravenous methylprednisolone 1g once every month in preventing the development of gadolinium-enhanced lesions in patients with very active RRMS or SPMS (double-blind assessment using MRI scans). After 6 months, significantly more combination therapy recipients had no new gadolinium-enhanced lesions (90.5% vs 31.3% with monotherapy; p < 0.001) [primary endpoint]. There were also significant reductions in both the mean number of new enhancing lesions and the total number of gadolinium-enhanced lesions in patients receiving combination therapy versus methylprednisolone monotherapy.Tolerability. Mitoxantrone was generally well tolerated in patients with MS. Treatment-emergent adverse events occurring significantly more frequently with mitoxantrone (12 mg/m(2) once every 3 months for 2 years) than placebo were nausea, alopecia, menstrual disorders, urinary tract infection, amenorrhoea, leucopenia and elevated gamma-glutamyltranspeptidase levels. Adverse events were usually mild to moderate in severity and generally resolved with discontinuation of treatment or when treated with appropriate pharmacotherapy. Eight percent of patients discontinued treatment in the mitoxantrone 12 mg/m(2) group due to an adverse event versus 3% of placebo recipients. The incidence of drug-related acute myelogenous leukaemia was very low (0.12%) in a cohort of 802 patients with MS receiving mitoxantrone. Evidence suggests that the risk of cardiotoxicity is low in patients with MS. After 1 year of monotherapy, 3.4% of mitoxantrone recipients had a reduction in left ventricular ejection fraction (LVEF) to < or =50% compared with 0% of placebo recipients; at the end of the second year, respective incidences were 1.9% and 2.9% (total cumulative dose of mitoxantrone per patient was 96 mg/m(2) after 2 years' treatment). (ABSTRACT TRUNCATED)

Pharmacokinetics and pharmacodynamics of IFN-beta 1a in healthy volunteers

The pharmacokinetics of recombinant human interferon-beta1a (IFN-beta1a) (Rebif, Ares-Serono, Geneva, Switzerland) were investigated in healthy volunteers following intravenous (i.v.) administration of increasing single doses of the drug (22 microg/6 million international units [MIU], 44 microg/12 MIU, and 66 microg/18 MIU); i.v., intramuscular (i.m.), and subcutaneous (s.c.) administration of a 66-microg dose; and repeated s.c. administration of four 66-microg doses at 48-h intervals. The disposition of IFN-beta1a followed triexponential decay after i.v. administration (half-lives 3 min, 42 min, and 22 h, respectively). After s.c. and i. m. administration, absorption was the rate-limiting factor in the terminal phase. The median absolute bioavailabilities were 30% and 27%, respectively. The accumulation ratio after repeated s.c. injections was 2.4, and a terminal half-life of 66 h was observed. Intracellular 2-5A synthetase activity and serum neopterin and beta2-microglobulin concentrations increased after all IFN-beta1a injections and remained elevated following every-other-day administration. The local tolerance was good, and the systemic tolerance was satisfactory.

Recombinant human interferon beta in relapsing-remitting multiple sclerosis: a review of the major clinical trials

The beneficial effects of interferon beta (IFN-beta) on disease activity in relapsing-remitting multiple sclerosis (RRMS) have been confirmed in several clinical trials. Three IFN-beta products are currently available and licensed for use in RRMS at different dosages and with different routes of administration. For the prescribing physician, therefore, questions remain about the effect these differences may have on the success of therapy. This paper reviews the four large placebo-controlled clinical trials that have been conducted with IFN-beta in patients with RRMS. The evidence available indicates that optimal results are likely to be achieved with the highest tolerable dosage of IFN-beta. Furthermore, as inflammatory brain lesions in MS have been shown to exhibit more extensive and early axonal damage than previously suspected, early treatment may be advisable in order to delay disease progression in RRMS.