Dose and Frequency of Administration of Interferon-?? Affect its Efficacy in Multiple Sclerosis

Considerations for Use of Pharmacodynamic Biomarkers to Support Biosimilar Development - (III) A Randomized Trial with Interferon Beta-1a Products

The US Food and Drug Administration (FDA) has taken steps to bring efficiency to the development of biosimilars, including establishing guidance for the use of pharmacokinetic and pharmacodynamic (PD) similarity study data without a comparative clinical study with efficacy end point(s). To better understand the potential role for PD biomarkers in biosimilar development and inform best practices for biomarker selection and analysis, we conducted a randomized, double-blinded, placebo-controlled, single-dose, parallel-arm clinical study in healthy participants. Eighty-four healthy participants (n = 12 per dose arm) received either placebo or one of three doses of either interferon β-1a (7.5-30 μg) or pegylated interferon β-1a (31.25-125 μg) to evaluate the maximum change from baseline and the baseline-adjusted area under the effect curve for the biomarkers neopterin in serum and myxovirus resistance protein 1 in blood. Both PD biomarkers increased following product administration with clear separation from baseline (neopterin: 3.4-fold and 3.9-fold increase for interferon β-1a and pegylated interferon β-1a, respectively; myxovirus resistance protein 1: 19.0-fold and 47.2-fold increase for interferon β-1a and pegylated interferon β-1a, respectively). The dose-response curves support that therapeutic doses were adequately sensitive to detect differences in both PD biomarkers for consideration in a PD similarity study design. Because baseline levels of both biomarkers are low compared with on-treatment values, there was little difference in using PD measures adjusted to baseline compared with the results without baseline adjustment. This study illustrates potential methodologies for evaluating PD biomarkers and an approach to address information gaps when limited information is publicly available for one or more PD biomarkers.

Standard Dose Weekly Intramuscular Beta Interferon-1a May Be Inadequate for Some Patients with Multiple Sclerosis: A 19-Year Clinical Experience Using Twice a Week Dosage

INTRODUCTION

Results from several clinical trials suggest there is a dose-response effect for beta interferon-1a (INFβ1a) in multiple sclerosis (MS).

METHODS

Our objective was to confirm these results through a retrospective analysis of patients with MS who had breakthrough disease (BD) on intramuscular (IM) INFβ1a (Avonex®) once per week (QW), who were switched to twice per week (BIW) IM INFβ1a between 1995 and 2015. The primary outcome measure was no further BD for at least 24 months. A secondary outcome measure was decrease in mean percentage of disease activity over time. BD was defined as continued relapses, new T2 or enhanced lesions on magnetic resonance imaging (MRI) of the brain, or worsening of the Expanded Disability Status Scale (EDSS) or the neurological examination.

RESULTS

Among 92 patients on QW IM INFβ1a, 53 patients with BD were switched to BIW IM INFβ1a. Of these 53 patients, 44 had adequate follow-up for at least 2 years. Twenty-three of these had no further BD for 24 months or more (range 24-192 months). Beta interferon neutralizing antibody testing was negative in 19 patients. An intent-to-treat analysis of the uncensored data from 52 switched patients also supported a treatment benefit.

CONCLUSION

For patients with MS having breakthrough disease on QW INFβ1a, switching to more frequently administered INFβ may be an option. Advantages to using IM INFβ1a for this include no skin reactions and a lower incidence of neutralizing antibodies. Further pragmatic, observational, larger-group studies comparing treatment with Avonex® and higher dosed IM INFβ1a, such as the recently FDA-approved IM peginterferon beta-1a, may be indicated.

IFN-β signaling dampens microglia reactivity but does not prevent from light-induced retinal degeneration

Chronic activation of microglia is associated with retinal degeneration, which makes them a potential therapeutic target for retinal degenerative diseases including age-related macular degeneration (AMD). Interferon-beta (IFN-β) is a potent immune regulator, commonly used for the treatment of multiple sclerosis patients. We have previously shown that IFN-β prevents microgliosis and choroidal neovascularization in a laser model of wet AMD. Here, we hypothesized that microglia modulation via IFN-β may also dampen mononuclear phagocyte reactivity and thereby protect from retinal degeneration in a light-damage paradigm mimicking some features of dry AMD. BALB/cJ mice received intraperitoneal injections of 10,000 U IFN-β or vehicle every other day; starting at the day of exposure to 15,000 lux white light for 1 h. Systemic treatment with IFN-β partially enhanced IFN-α/β receptor (IFNAR) signaling in the retina and reduced the number of reactivated microglia in the subretinal space. However, four days after light damage neither decreased expression of complement factors nor rescue of retinal thickness was found. We conclude that IFNAR signaling modulate retinal microglia but cannot prevent strong retinal degeneration as elicited by acute white light damage.

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Intraperitoneal application of IFN-β increases IFNAR signaling in the retina.

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IFN-β administration reduces microglia migration to the subretinal space.

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Light-induced retinal degeneration is not restored by IFN-β therapy.

Treatment of Experimental Autoimmune Encephalomyelitis by Sustained Delivery of Low-Dose IFN-α

Multiple sclerosis (MS) is a chronic autoimmune disease with no curative treatment. The immune regulatory properties of type I IFNs have led to the approval of IFN-β for the treatment of relapsing-remitting MS. However, there is still an unmet need to improve the tolerability and efficacy of this therapy. In this work, we evaluated the sustained delivery of IFN-α1, either alone or fused to apolipoprotein A-1 by means of an adeno-associated viral (AAV) system in the mouse model of myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis. These in vivo experiments demonstrated the prophylactic and therapeutic efficacy of the AAV-IFN-α or AAV-IFN-α fused to apolipoprotein A-1 vectors in experimental autoimmune encephalomyelitis, even at low doses devoid of hematological or neurologic toxicity. The sustained delivery of such low-dose IFN-α resulted in immunomodulatory effects, consisting of proinflammatory monocyte and T regulatory cell expansion. Moreover, encephalitogenic T lymphocytes from IFN-α-treated mice re-exposed to the myelin oligodendrocyte glycoprotein peptide in vitro showed a reduced proliferative response and cytokine (IL-17A and IFN-γ) production, in addition to upregulation of immunosuppressive molecules, such as IL-10, IDO, or PD-1. In conclusion, the results of the present work support the potential of sustained delivery of low-dose IFN-α for the treatment of MS and likely other T cell-dependent chronic autoimmune disorders.