Matching-adjusted indirect treatment comparison of siponimod and other disease modifying treatments in secondary progressive multiple sclerosis

Disease-modifying therapies for relapsing/active secondary progressive multiple sclerosis - a review of population-specific evidence from randomized clinical trials

Although the understanding of secondary progressive multiple sclerosis (SPMS) is evolving, early detection of relapse-independent progression remains difficult. This is further complicated by superimposed relapses and compensatory mechanisms that allow for silent progression. The term relapsing multiple sclerosis (RMS) subsumes relapsing-remitting multiple sclerosis (RRMS) and SPMS with relapses. The latter is termed 'active' SPMS, for which disease-modifying therapies (DMTs) approved for either RMS or active SPMS can be used. However, the level of evidence supporting efficacy and safety in SPMS differs between drugs approved for RMS and SPMS. Our review aims to identify current evidence from published clinical trials and European public assessment reports from the marketing authorization procedure on the efficacy, especially on progression, of DMTs approved for RMS and SPMS. To identify relevant evidence, a literature search has been conducted and European public assessment reports of DMTs approved for RMS have been screened for unpublished data specific to SPMS. Only two clinical trials demonstrated a significant reduction in disability progression in SPMS study populations: the EXPAND study for siponimod, which included a typical SPMS population, and the European study for interferon (IFN)-beta 1b s.c., which included patients with very early and active SPMS. Both DMTs also achieved significant reductions in relapse rates. Ocrelizumab, cladribine, ofatumumab, and ponesimod are all approved for RMS - ocrelizumab, ofatumumab, and ponesimod based on an RMS study, cladribine based on an RRMS study. Data on efficacy in SPMS are only available from post hoc analyses of very small subgroups, representing only up to 15% of the total study population. For these DMTs, approval for RMS, including active SPMS, was mainly based on the assumption that the reduction in relapse rate observed in patients with RRMS can also be applied to SPMS. Based on that, the potential of these drugs to reduce relapse-independent progression remains unclear.

Secondary Progressive Multiple Sclerosis

Many challenges exist in the precise diagnosis and clinical management of secondary progressive multiple sclerosis (SPMS) because of the lack of definitive clinical, imaging, immunologic, or pathologic criteria that demarcate the transition from relapsing-remitting MS to SPMS. This review provides an overview of the diagnostic criteria/definition and the heterogeneity associated with different SPMS patient populations; it also emphasizes the importance of available prospective/retrospective tools to identify patients with SPMS earlier in the disease course so that approved disease-modifying therapies and nonpharmacological strategies will translate into better outcomes. Delivery of such interventions necessitates an evolving patient-clinician dialog within the context of a multidisciplinary team.

How do patients with secondary progressive multiple sclerosis enrolled in the EXPAND randomized controlled trial compare with those seen in German clinical practice in the NeuroTransData multiple sclerosis registry?

Background

In EXPAND (NCT01665144), a phase 3 randomized clinical trial, siponimod reduced disability progression versus placebo in patients with secondary progressive multiple sclerosis (SPMS).

Aim

To understand how a real-world population with SPMS relates to that in EXPAND, we conducted a retrospective, observational cohort study using the German NeuroTransData (NTD) multiple sclerosis (MS) registry.

Methods

The NTD MS registry is run by a Germany-wide network of physicians. Two cross-sectional analyses were performed using the NTD MS registry. The first included patients with SPMS, as recorded in the registry, and compared their characteristics between 1 January 2018 and 31 December 2018 with patients in EXPAND. The second described the characteristics of patients in the registry at the time of diagnosis of SPMS between 1 January 2010 and 31 December 2018.

Results

The first analysis included 773 patients: patients were older in the NTD MS registry than in EXPAND (mean age, 57.9 vs 48.0 years) and had a longer duration of SPMS (mean, 6.2 vs 3.8 years). In the NTD MS registry, median Expanded Disability Status Scale (EDSS) scores were comparable to EXPAND (6.0 versus 6.0), although fewer patients had relapses in the previous 24 months (16% vs 36% [siponimod] and 37% [placebo]). Data on gadolinium-enhancing lesions were only available for 5.8% of patients in the NTD MS registry. The second analysis included 916 patients: at the time of SPMS diagnosis, the mean age was 53.2 years and the median EDSS score was 5.0.

Conclusion

The population in the NTD MS registry was older to that in EXPAND, but were similar in terms of disability. Differences likely reflect the inclusion criteria of EXPAND but also highlight that real-world populations encompass a wider range of patient characteristics.

Cost-effectiveness and budget impact analysis of siponimod in the treatment of secondary progressive multiple sclerosis in Italy

Background

Siponimod is an effective treatment for patients with secondary progressive multiple sclerosis (SPMS), with active disease evidenced by relapses or imaging features characteristic of multiple sclerosis inflammatory activity, however there is a need to evaluate its economic value and sustainability compared to other disease modifying-therapies (DMTs).

Objective

To estimate the siponimod cost-effectiveness profile and its relative budget impact compared with other DMTs, by using the Italian National Healthcare System perspective.

Methods

We performed: 1) a cost-effectiveness analysis (CEA) vs interferon beta-1b using an analytical Markov model and a life time-horizon, and 2) a budget impact analysis by using 3-years time-horizon. The results were reported as incremental cost-effectiveness ratio (ICER) and net-monetary benefit (NMB) for CEA, using a willingness to pay threshold of €40,000 per QALY gained, and as difference in the overall budget (Euro) between the scenario with and without siponimod for budget impact.

Results

In the base case scenario siponimod resulted cost-effective compared with interferon beta-1b 28,891€ per QALY. Overall, the market access of siponimod was associated to an increased budget of about 3€ millions (+0.9%) in the next 3 years simulated.

Conclusion

Compared to interferon beta-1b, siponimod seems to be cost-effective in SPMS patients and sustainable, with less than 1% overall budget increased in the next 3 years. Future studies need to confirm our results in the real word setting and in other countries.

Cost Effectiveness and Budget Impact of Siponimod Compared to Interferon Beta-1a in the Treatment of Adult Patients with Secondary Progressive Multiple Sclerosis with Active Disease in Switzerland

OBJECTIVE

The study aim was to evaluate the cost effectiveness and budget impact of siponimod compared to interferon beta-1a for adult patients with secondary progressive multiple sclerosis (SPMS) with active disease, from a Swiss health insurance perspective.

METHODS

We conducted an analysis using a Markov cohort model with a cycle length of 1 year, life-long time horizon, and discount rate of 3% for cost and health outcomes. We used a matching-adjusted indirect comparison to estimate clinical outcomes using data from the EXPAND randomised controlled trial of siponimod vs placebo and the Nordic SPMS randomised controlled trial of interferon beta-1a vs placebo as the basis for estimates of disability progression and relapse outcomes. We used 6-month confirmed disability progression results to estimate disability progression in the base-case analysis. We calculated quality-adjusted life-years (QALYs) based on an external study that administered the EQ-5D-3L questionnaire to European patients with multiple sclerosis. We included costs (Swiss Franc (CHF), year 2020) of drug acquisition/administration, adverse events and disease management. We also performed a budget impact analysis to estimate the cost over the first 3 years of introducing siponimod.

RESULTS

For the base case, siponimod resulted in mean incremental costs of CHF 84,901 (siponimod: CHF 567,838, interferon beta-1a: CHF 482,937) and mean incremental QALYs of 1.591 (siponimod: 7.495, interferon beta-1a: 5.905), leading to an incremental cost-effectiveness ratio of CHF 53,364 per QALY gained. In the probabilistic sensitivity analysis, the probability of the cost effectiveness of siponimod assuming a willingness-to-pay threshold of CHF 100,000 per QALY gained was 90%. Siponimod was projected to result in drug administration costs for siponimod of CHF 23,817,856 in the first 3 years after introduction, accompanied by large cost offsets in drug acquisition of other multiple sclerosis drugs. Considering drug administration, monitoring and adverse event management costs, it was estimated to result in additional healthcare costs in Switzerland of CHF 2,177,021.

CONCLUSIONS

In the base-case analysis, we found that siponimod may be cost effective for treating Swiss adult patients with SPMS with active disease. The results of the cost-effectiveness analyses are valid under the assumption that the efficacy of siponimod and the comparators on disability progression for the overall SPMS population would be the same in the active SPMS population.

CLINICAL TRIAL IDENTIFIER

NCT01665144. This economic evaluation was based on the EXPAND trial.

Therapeutic Value of Single Nucleotide Polymorphisms on the Efficacy of New Therapies in Patients with Multiple Sclerosis

The introduction of new therapies for the treatment of multiple sclerosis (MS) is a very recent phenomenon and little is known of their mechanism of action. Moreover, the response is subject to interindividual variability and may be affected by genetic factors, such as polymorphisms in the genes implicated in the pathologic environment, pharmacodynamics, and metabolism of the disease or in the mechanism of action of the medications, influencing the effectiveness of these therapies. This review evaluates the impact of pharmacogenetics on the response to treatment with new therapies in patients diagnosed with MS. The results suggest that polymorphisms detected in the GSTP1, ITGA4, NQO1, AKT1, and GP6 genes, for treatment with natalizumab, ZMIZ1, for fingolimod and dimethyl fumarate, ADA, for cladribine, and NOX3, for dimethyl fumarate, may be used in the future as predictive markers of treatment response to new therapies in MS patients. However, there are few existing studies and their samples are small, making it difficult to generalize the role of these genes in treatment with new therapies. Studies with larger sample sizes and longer follow-up are therefore needed to confirm the results of these studies.

Living with secondary progressive multiple sclerosis in Europe: perspectives of multiple stakeholders

The transition from relapsing-remitting multiple sclerosis to secondary progressive multiple sclerosis (SPMS) remains a clinical challenge owing to the heterogeneous course of the disease, indistinct disease progression and lack of availability of validated biomarkers and diagnostic tools. This article summarizes the outcomes from an international expert group meeting conducted to validate the preliminary research findings gathered through interviews with primary healthcare stakeholders and pharmaceutical representatives, and to understand the current and future patient journey of SPMS across seven European countries. We highlight the uncertainty in SPMS diagnosis and management and, consequently, the need for uniform assessment guidelines, enhanced awareness and a collaborative effort between the stakeholders associated with SPMS patient care and the pharmaceutical industry.

Does Siponimod Exert Direct Effects in the Central Nervous System?

The modulation of the sphingosine 1-phosphate receptor is an approved treatment for relapsing multiple sclerosis because of its anti-inflammatory effect of retaining lymphocytes in lymph nodes. Different sphingosine 1-phosphate receptor subtypes are expressed in the brain and spinal cord, and their pharmacological effects may improve disease development and neuropathology. Siponimod (BAF312) is a novel sphingosine 1-phosphate receptor modulator that has recently been approved for the treatment of active secondary progressive multiple sclerosis (MS). In this review article, we summarize recent evidence suggesting that the active role of siponimod in patients with progressive MS may be due to direct interaction with central nervous system cells. Additionally, we tried to summarize our current understanding of the function of siponimod and discuss the effects observed in the case of MS.

The importance of considering differences in study and patient characteristics before undertaking indirect treatment comparisons: a case study of siponimod for secondary progressive multiple sclerosis

Background: Indirect treatment comparisons (ITCs) provide valuable evidence on comparative efficacy where head-to-head clinical trials do not exist; however, differences in patient populations may introduce bias. Therefore, it is essential to assess between-trial heterogeneity to determine the suitability of synthesizing ITC results. We provide an illustrative case study in multiple sclerosis (MS) where we assess the feasibility of conducting ITCs between siponimod and interferon beta-1b (IFN β-1b) and between siponimod and ocrelizumab.Methods: We assessed the feasibility of conducting ITCs using standard unadjusted methods (e.g. Bucher or network meta-analysis [NMA]) as well as matching-adjusted indirect comparisons (MAICs) using individual patient data (IPD) from the siponimod (EXPAND) trial, based on guidance from NICE. Time to confirmed disability progression (CDP) at 3 or 6 months was assessed.Results: Bucher ITCs and NMAs, which rely on summary-level data, were not able to account for important cross-trial differences. Comparisons between siponimod and IFN β-1b were feasible using MAIC; the HRs (95% CI) for CDP-6 and CDP-3 were 0.55 (0.33-0.91) and 0.82 (0.42-1.63), respectively. ITCs were not feasible between siponimod and ocrelizumab because study designs and patient populations were too dissimilar to conduct a reliable ITC.Conclusions: This study highlights the importance of conducting a detailed feasibility assessment before undertaking ITCs to illuminate when excessive between-trial heterogeneity would cause biased results. MAIC was performed for siponimod and IFN β-1b in the absence of a head-to-head trial and was considered a more valid approach than a traditional ITC to examine comparative effectiveness.