Intravenous Immunoglobulin Treatment in Autoimmune Neurological Disorders—Effects on Quality of Life

Use of Health Technology Assessment for the Continued Funding of Health Technologies: The Case of Immunoglobulins for the Management of Multifocal Motor Neuropathy

INTRODUCTION

Funding decisions for many health technologies occur without undergoing health technology assessment (HTA), in particular, without assessment of cost effectiveness (CE). Immunoglobulins in Australia are an interesting case study because they have been used for a long time for various rare disorders and their price is publicly available. Undertaking an HTA enables us to assess CE for an intervention for which there is limited clinical and economic evidence. This study presents a post-market review to assess the CE of immunoglobulins for the treatment of multifocal motor neuropathy (MMN) compared with best supportive care.

METHODS

A Markov model was used to estimate costs and quality-adjusted life-years (QALYs). Input sources included randomised controlled trials, single-arm studies, the Australian clinical criteria for MMN, clinical guidelines, previous Medical Services Advisory Committee (MSAC) reports and inputs from clinical experts. Sensitivity analyses were conducted to assess the uncertainty and robustness of the CE results.

RESULTS

The cost per patient of treating MMN with immunoglobulin was AU$275,853 versus AU$26,191when no treatment was provided, with accrued QALYs of 6.83 versus 6.04, respectively. The latter translated into a high incremental cost-effectiveness ratio (ICER) of AU$317,552/QALY. The ICER was most sensitive to the utility weights and the price of immunoglobulins. MSAC advised to continue funding of immunoglobulins on the grounds of efficacy, despite the high and uncertain ICER.

CONCLUSIONS

Beyond the ICER framework, other factors were acknowledged, including the high clinical need in a patient population for which there are no other active treatments available. This case study highlights the challenges of conducting HTA for already funded interventions, and the efficiency trade-offs required to fund effective high-cost therapies in rare conditions.

Limitations in daily activities and general perception of quality of life: Long term follow-up in patients with anti-myelin-glycoprotein antibody polyneuropathy

In this study, we assessed the modifications over time of daily activities and quality of life (QoL) in 32 subjects with anti-myelin-glycoprotein (MAG) antibody neuropathy. A widespread panel including clinical scores and patient-reported questionnaires, in compliance of the terms by the International Classification of Functioning, Disability, and Health (ICF) of the World Health Organization (WHO), was employed at enrollment (T0) and at follow-up evaluation (T1) after a mean interval of 15.4 ± 5.7 months. The Sensory Modality Sum score (SMS) at four limbs showed a significant worsening over time (mean score 27.2 ± 3.9 at T0 vs 25.7 ± 3 at T1 at upper limbs, P = .03; 20.5 ± 4.8 at T0 vs 18.6 ± 5.9 at T1 at lower limbs, P = .04). The Visual Analogue Scale (VAS) for pain significantly worsened at upper limbs at T1 (mean values 0.84 ± 1.95 at T0 vs 1.78 ± 2.6 at T1, P = .03). All the other tests did not show significant differences between T0 and T1. In the subgroup who underwent rituximab (15/32 treated before T0, 3/32 patients treated between T0 and T1 with median interval of 1 year), no significant differences were observed between T0 and T1. Despite the quite long follow-up, statistical significance was not achieved either for the limited number of patients or for the lack of sensitive outcome measures. In our cohort, the significant worsening of the SMS and VAS after a median of 14 months can be considered as a reliable expression of the natural history of the disease, and suggest that these scales might represent possible outcome measures in anti-MAG antibody neuropathy.

Functioning and quality of life in patients with neuropathy associated with anti-MAG antibodies

Although anti-myelin-associated glycoprotein (MAG) antibody neuropathy is reported as a slowly progressive disease, it can lead to significant disability and impairment of health-related quality of life (HR-QoL) and social participation. The aim of this cross-sectional study was to evaluate the functioning and HR-QoL determinants in 67 patients with anti-MAG neuropathy in terms of the International Classification of Functioning, Disability, and Health (ICF). Evaluations included: Medical Research Council (MRC) sum score, Sensory Modality Sum score (SMS), Berg balance scale (BBS), Fatigue Severity Scale (FSS), Visual Analogue Scale (VAS) for pain, 9-Hole Peg Test (9-HPT), 6-min Walk Distance (6MWD), Impact on Participation and Autonomy (IPA) and the physical component score (PCS) and mental component score (MCS) of the short-form-36 health status scale (SF-36) HR-QoL measure. In the regression models, 6MWD was the most reliable predictor of PCS, explaining the 52% of its variance, while the strongest determinants of 6MWD were BBS and FSS, explaining the 41% of its variance. Consistently, VAS and BBS were good predictor of PCS, explaining together 54% of its variance. FSS was the most reliable determinant of MCS, explaining 25% of its variance. SMS and MRC were not QoL determinants. The results of our study suggest that 6MWD and FSS might be considered as potential meaningful outcome measures in future clinical trials. Furthermore, neurorehabilitation interventions aimed at improving balance and walking performance, fatigue management, and specific pain relief therapy should be considered to ameliorate participation in social life and HR-QoL in anti-MAG neuropathy patients.

Efficacy of Various Intravenous Immunoglobulin Therapy Protocols in Autoimmune and Chronic Inflammatory Disorders

Objective:

To determine the efficacy of various intravenous immunoglobulin (IVIG) protocols used in the treatment of autoimmune and chronic inflammatory disorders.

Data Sources:

Literature retrieval was accessed through MEDLINE (November 1984–March 2007) and a search was conducted using the term intravenous immunoglobulin. References cited in the selected articles were also reviewed.

Study Selection and Data Extraction:

Inclusion criteria for studies were (1) English language, (2) randomized controlled trials, (3) defined protocols, (4) a minimum of 15 patients, and (5) objective criteria provided to assess clinical outcomes and course.

Data Synthesis:

The therapeutic efficacy of IVIG therapy is well established, and defined protocols exist for treatment of Kawasaki disease, immune thrombocytopenic purpura, Guillain–Barré syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and autoimmune mucocutaneous blistering diseases. In the absence of a defined protocol, studies have demonstrated that IVIG therapy is effective in the treatment of myasthenia gravis, dermatomyositis, stiff person syndrome, antineutrophil cytoplasmic antibody positive systemic vasculitides, Graves' ophthalmopathy, and certain forms of systemic lupus erythematosus. It might also be of benefit in some patients with relapsing–remitting multiple sclerosis. The outcomes are variable in these studies. In toxic epidermal necrolysis and Stevens–Johnson syndrome, use of IVIG has dramatically influenced clinical response and reduced mortality.

Conclusions:

The cumulative evidence suggests that the clinical outcomes observed are significantly influenced by the use of a defined protocol. There is a need for multicenter trials approved by the Food and Drug Administration to better define the role of IVIG in many disease states. Such studies would be able to establish the indications for use, optimal dose, frequency of infusions, duration of therapy, and need for gradual withdrawal versus sudden cessation. Defined protocols resulting from the study of a large cohort of patients often convince insurance companies to create policies that provide access to IVIG therapy.