Budget Impact Analysis of Biosimilar Natalizumab in the US

, , , , ,

Projected savings from biosimilar natalizumab were $452,611 over 3 years, driven by decreased drug acquisition costs and a utilization shift from reference to biosimilar natalizumab.

This article was originally published in The American Journal of Managed Care®.

ABSTRACT

Objectives: Biosimilars provide an opportunity for a more sustainable and cost-effective treatment for multiple sclerosis (MS). This study evaluated the potential financial impact of implementing a formulary change from reference to biosimilar natalizumab (NTZ) from the US commercial payer perspective.

Study Design: The budget impact of transitioning to biosimilar NTZ for the treatment of relapsing-remitting MS (RRMS) was estimated over a 3-year time horizon based on real-world dosing. Additional scenario analyses were conducted by varying the price differential of biosimilar NTZ.

Methods: The target population was estimated from a 1-million-member hypothetical commercial health plan. Model inputs were drug acquisition costs and treatment-related and patient coinsurance costs. Budget impact and cost savings per member per year were calculated by assuming a biosimilar uptake of 10% in year 1 to 20% in year 3.

Results: Over 3 years, 255 patients were estimated to be treated with high-efficacy disease-modifying therapies for RRMS. The inclusion of biosimilar NTZ onto a formulary would result in cumulative cost savings to payers of $452,611 over 3 years, with mean savings per treated member per year of $1179, $1769, and $2359 in years 1, 2, and 3, respectively. One-way sensitivity analyses indicated that budget impact results were most sensitive to drug acquisition costs of both reference and biosimilar NTZ.

Conclusion: Adoption of biosimilar NTZ can yield considerable cost savings to US health plans that could result in increased treatment access for patients with RRMS.

Am J Manag Care. 2024;30(7):e191-e197. https://doi.org/10.37765/ajmc.2024.89558

_____

Takeaway Points

Disease-modifying therapies (DMTs) for relapsing-remitting multiple sclerosis have been available for more than 25 years, yet DMT-related costs continue to be a concern, especially with the advent of biologic DMTs. We estimated the financial impact of implementing a formulary inclusion of biosimilar natalizumab from a US payer perspective:

  • The inclusion of biosimilar natalizumab onto a formulary would result in mean savings per treated member per year of $1179, $1769, and $2359 in years 1, 2, and 3, respectively.
  • Annualized costs for a biosimilar natalizumab can be lower than those for reference high-efficacy DMTs when considering real-world dosing patterns.

_____

Multiple sclerosis (MS) is a chronic disease characterized by neural inflammation, demyelination, and neurodegeneration, mainly affecting young adults around the world. Most individuals with MS experience a variety of debilitating symptoms with periodic neurological relapses that impact their quality of life, employment, social relationships, and productivity.1,2 The global incidence and prevalence of MS is rising; in 2020, 2.8 million individuals were living with MS compared with 2.3 million in 2013.3 The US is among the countries with the highest prevalence of MS, with 288 MS cases per 100,000 individuals,4,5 and a recent study reported that approximately 1 million adults are living with MS nationwide.2 MS disproportionately impacts women; it is nearly 2 to 3 times more prevalent in women than men.6 MS can occur at any age, and the mean age of diagnosis is 32 years.5 The peak MS prevalence was observed among both male and female patients aged 45 to 49 years,7 and the peak incidence was observed in patients aged 25 to 29 years.8 MS also has a strong racial and ethnic component and disproportionately affects more individuals with northern European ancestry and Black individuals.9

Relapsing-remitting MS (RRMS) is the most common phenotype, accounting for approximately 85% of cases.10 Patients with RRMS experience episodic flare-ups of symptoms followed by periods of remission.10 Disease-modifying therapies (DMTs) are used to treat MS and significantly reduce clinical relapses, slow disease disability and progression, minimize MRI lesion activity, and improve patient quality of life.11-14 High-efficacy DMTs such as natalizumab (NTZ), ocrelizumab, and alemtuzumab are biologic therapies commonly given in infusion centers and are known for average relapse reduction of more than 50%.15 MS is one of the costliest chronic diseases for payers in the US. Its estimated total economic burden was $85.4 billion in 2019 in both direct and indirect costs to patients.16 Based on one large payer’s analysis, the MS drug category ranks fourth in spend, behind the autoimmune, cancer, and HIV drug categories.17 A study by Bebo et al estimated the economic burden of MS in the US and found that the direct medical cost for a patient with MS was $65,612 per year, with the majority of that being the cost of DMTs (53.6%).16 Among individuals using DMTs, annual DMT costs ranged from $57,202 to $92,719.16 In a survey among patients with RRMS, high out-of-pocket (OOP) costs were frequently reported as a DMT access barrier.18

There is evidence in the US of health care cost savings following the entry of generic MS drugs. For example, the launch of generic glatiramer acetate coincided with a decline in gross sales of glatiramer acetate injection from approximately $4.5 million (2015) to approximately $2.5 million (2019); glatiramer acetate injection accounted for 33% and 32% of total DMT prescriptions in 2015 and 2019, respectively.19 In a similar manner, the introduction of a biosimilar for the treatment of RRMS could help address issues of high spending and access barriers to high-efficacy MS therapies.20 Sandoz Inc’s biosimilar NTZ is the first biosimilar NTZ approved in the US.21 A confirmatory phase 3 study demonstrated the matching efficacy and safety of biosimilar NTZ to that of the reference medicine.22 The purpose of this economic analysis was to estimate the potential financial impact from the payer perspective of the inclusion of biosimilar NTZ onto a drug formulary.

METHODS

A budget impact model was developed in Excel (Microsoft) to estimate the financial impact of introducing biosimilar NTZ to the high-efficacy DMT space for treatment of adult patients with RRMS in a hypothetical 1-million-member US commercial health plan over a 3-year time horizon. The model was developed according to Modeling Good Research Practices guidance from ISPOR—The Professional Society for Health Economics and Outcomes Research.23 A schematic of the model structure is shown in eAppendix Figure 1 (eAppendix available at ajmc.com).

The patient population of interest was adult patients with RRMS who were treated with high-efficacy infused DMTs, aged 20 to 64 years, and covered by commercial insurance. Three high-efficacy DMTs—NTZ, alemtuzumab, and ocrelizumab—were included in the analysis to represent the technology mix of high-efficacy infused DMTs in the US as recommended by the ISPOR budget impact analysis guideline.24 The model estimated expected total cost and budget impact on an overall and per-member basis with and without the introduction of biosimilar NTZ onto a formulary. The main model parameters are outlined in Table 1.

The model inputs included estimates of epidemiological data, relapse rates, dosing, utilization rates, and costs. Costs to payers included drug acquisition, administration, monitoring, relapse, and adverse event (AE) management costs. All costs were obtained from literature and adjusted to 2021 US$. In accordance with recommended practice for short-term budget impact analyses, we did not apply discounting on costs to derive present values.24

Base-Case Model Inputs and Data Sources

Model population. Although biosimilar NTZ has the same indications as reference NTZ, this model focused on the most common phenotype of MS: RRMS. The population of interest was patients with RRMS (treatment-naive patients and patients with existing treatment) aged 20 to 65 years who were currently being treated with or newly started on infused high-efficacy DMTs.25,26

The annual incidence and prevalence rates of MS were assumed to be constant over the 3-year time horizon of the analysis. RRMS incidence and prevalence were age adjusted by age groups from US census data, age-specific incidence and prevalence of MS, and the proportion of patients with RRMS in the US.7,8,27-29 These model inputs are presented in eAppendix Table 1.

Perspective. The analysis was conducted from a US commercial payer perspective. Analysis of the budget impact from a Medicare perspective is presented separately in eAppendix Section C.

Dosing. In the base-case analysis, we assumed dosing frequency derived from published real-world studies.30,31 The findings from multiple studies indicate that clinicians in the US are prescribing and administering NTZ less frequently than the FDA-labeled dosing (theoretical setting), which is associated with a reduction in the risk of progressive multifocal leukoencephalopathy.31,32 In addition, patients receiving ocrelizumab and alemtuzumab in real-world settings were observed to require more doses than on label to control relapses, as highlighted by Nicholas et al.30 The total number of doses administered in a year are given in eAppendix Table 2.

Cost. Drug acquisition costs were derived from wholesale acquisition costs (WACs) from IBM Redbooks(dated July 1, 2021), similar to other recent budget impact analysis studies.33-35 The base-case WAC price for biosimilar NTZ was assumed to be 15% lower than the cost of reference NTZ based on the historical experience of other biosimilar launches in the US.36 The WAC drug price for each drug is shown in eAppendix Table 3.

Costs associated with administration, monitoring, and pretreatment for the included DMTs were obtained from a study conducted in 2020 by Kozma et al37 (given in eAppendix Section B).

AE treatment costs were obtained from a study by Chirikov et al.38 AE management costs for each DMT are shown in eAppendix Section B and were utilized to obtain the total AE cost for the treatment-naive and existing patients.

Relapse management costs of $3116 per episode were derived from literature (shown in eAppendix Section B).39 The annualized relapse rates for NTZ, ocrelizumab, and alemtuzumab were 0.19, 0.22, and 0.17, respectively, calculated based on relative risks from the Institute for Clinical and Economic Review.40

All treatment (non-DMT) costs obtained from literature were adjusted to 2021 US$ based on US Consumer Price Index inflation statistics.41

Utilization rates. The overall budget impact was calculated by assuming a 10%, 15%, and 20% uptake of biosimilar NTZ from reference NTZ in years 1, 2, and 3, respectively. Our uptake assumption of biosimilar NTZ is consistent with 3-year market shares of past biosimilar launches in the US since 2013.42,43 The utilization rates of ocrelizumab and alemtuzumab were assumed to remain constant.

Analysis: Base-Case Analysis Using Real-World Dosing Pattern

The number of patients continuing and newly starting treatment for each year was estimated using patient-year calculations and stratified by patients who switched to biosimilar NTZ and those who remained on reference NTZ, ocrelizumab, and alemtuzumab. Results with FDA label dosing are presented in eAppendix Section D.

A 1-way sensitivity analysis was performed to assess the impact of varying each base-case parameter by ±25% on the model outcomes. Additional analysis of price sensitivity is reported in eAppendix Section E.

RESULTS

Budget Impact for Payers

In the base-case analysis for a hypothetical 1-million-member health plan, 84 patients aged 20 to 64 years with RRMS (2 incident and 82 existing cases) were estimated to require high-efficacy DMT in year 1. Over the 3-year time horizon, it was estimated that 255 patient-years of high-efficacy DMTs would be provided (eAppendix Table 4).

In base-case analysis assuming real-world dosing patterns, the model estimates that the cumulative total cost of high-efficacy DMT over 3 years from the payer perspective is $21.1 million and can be reduced to $20.6 million with the inclusion of biosimilar NTZ. The formulary inclusion of biosimilar NTZ for RRMS could result in cumulative cost savings of $452,611 over 3 years, starting at $98,189 in year 1 and rising to $204,207 in year 3, as shown in Table 2.

Within this base-case analysis, payer cost savings were primarily driven by the decrease in drug acquisition costs due to the shift from reference NTZ to biosimilar NTZ, which we assume will have lower drug acquisition costs based on historical biosimilar experience.

Without biosimilar NTZ in the formulary for the commercial plan population, the per-member per-year (PMPY) cost was $6.90 in year 1 and up to $7.17 in year 3. The increased PMPY costs were due to the incorporation of annual population growth into the model. With biosimilar NTZ, PMPY costs were reduced to $6.80 in year 1 and $6.97 in year 3. The cost savings per treated member per year were $1179 in year 1, $1769 in year 2, and $2359 in year 3. The mean annual total cost per existing patient to the payer was found to be the lowest for biosimilar NTZ ($69,532) and higher for the other DMTs (reference NTZ [$81,262], ocrelizumab [$81,013], and alemtuzumab [$81,728]) (Table 3).

From a Medicare perspective analysis, 10 patient-years of high-efficacy DMT would be provided over 3 years. The inclusion of biosimilar NTZ into the formulary would generate cost savings of $18,642 over 3 years, equivalent to a mean cost savings per treated member per year of $1192 in year 1, $1786 in year 2, and $2380 in year 3. Detailed results for Medicare are provided in eAppendix Section C.

One-Way Sensitivity Analysis

The base-case results were most sensitive to the drug acquisition cost of reference NTZ and biosimilar NTZ (Figure). Results of price sensitivity analysis are reported in eAppendix Section E.

DISCUSSION

Biosimilar NTZ from Sandoz is the first biosimilar for the treatment of RRMS to be launched in the US. This budget impact model estimated that, assuming a 15% reduction between the WAC prices of reference NTZ and biosimilar NTZ, switching from the reference to biosimilar NTZ could result in savings of approximately $452,611 from a commercial payer’s perspective over a 3-year time horizon.

Our model assumed the lowest price differential between biosimilar and reference product from historical experience in the US; cumulative savings could be even higher if the price difference was at the historical maximum of 37%.36 Such savings to the US health care system would result in significant economic and social benefit to payers and patients. The 1-way sensitivity analysis revealed that the budget impact was most sensitive to variation in the WAC price of reference NTZ, followed by the predicted WAC price of biosimilar NTZ.

Besides reference and biosimilar NTZ, our model also included alemtuzumab and ocrelizumab as part of the treatment mix to provide additional context in this therapeutic area. In general, there is no uniform approach for DMT selection or sequencing for patients with RRMS, and product selection is influenced by patient preferences for efficacy, safety, tolerability, route of administration, and cost. Moreover, patients and their neurologists can switch from one DMT to another for any one of these reasons. There is, however, growing consensus that early use of higher-efficacy DMTs such as NTZ or ocrelizumab might be advantageous for improving long-term outcomes, and their use has increased.44 Although ocrelizumab has been demonstrated to be cost saving or more cost-effective vs NTZ, the emergence of a lower-cost, high-efficacy DMT, such as biosimilar NTZ, has the potential to produce significant cost savings for payers. We did not assume that NTZ (reference or biosimilar) would take market share from alemtuzumab or ocrelizumab within the short time frame of our analysis, although changes to the overall treatment mix between these high-efficacy DMTs are possible over the longer term.

Although reference NTZ is a high-efficacy DMT commonly used for the treatment of RRMS, since its approval in 2004, newer and less costly high-efficacy DMTs have been approved; these include ocrelizumab in 2017 and ublituximab in December 2022. Based on our model with lower biosimilar NTZ WAC prices and the use of real-world dosing patterns, our results (Table 3) showed that from the perspective of cost per treated patient per year, biosimilar NTZ would be on par with newer treatments such as ocrelizumab, especially after the first year of treatment. This in turn ensures continued patient access to highly efficacious DMTs and treatment alternatives within the drug class.

Despite the cost-saving advantages of biosimilars, there are many barriers to the entry of biosimilars in the US. The introduction of biosimilars in the US market is essential for increasing patient access and market competition and thus decreasing the overall treatment cost for both the government and payers. In the US, MS is associated with the highest OOP expenditure, including hospital and doctor bills, prescription drugs, and premiums, among the most common diagnoses such as diabetes, injuries, stroke, mental illnesses, and heart disease.45 With increasing global prevalence of MS, the utilization of DMTs has also increased because DMTs demonstrate high efficacy in reducing relapses, delaying disease progression, reducing disability, and improving the quality of life among patients with MS.11-14 However, despite the availability and proven efficacy of DMTs in patients with MS, affordability of DMTs remains a major challenge because of increasing costs.46 A recent cross-sectional study highlighted that nearly 70% of Medicare beneficiaries with MS were using a DMT and that for the patients who used DMTs consistently throughout the year, OOP costs were high.47 Although DMTs have been available to patients for more than 25 years, DMT-related costs continue to be high.48-51 Hence, health care plans should consider including the cost-saving treatments in their drug formulary, which could potentially reduce the financial burden.

This is the first study to assess from a US payer perspective the budget impact of introducing a high-efficacy DMT biosimilar into a formulary for the treatment of patients with RRMS. Our findings, however, should be interpreted with caution, as the estimated cost savings depend on many interrelated factors such as biosimilar price differential relative to the reference product, biosimilar uptake rate, and patient access to biosimilars. Biosimilars have been available in the US since 2015, and they have enabled the health care system to realize significant savings.52-54 The considerable potential savings on drug spending when patients switch from reference NTZ to biosimilar NTZ as observed in the present study are consistent with previous biosimilar literature (eAppendix Table 5).

As the promising cost savings due to biosimilars are emerging, a RAND study estimated total biosimilar savings of $38.4 billion from 2021 to 2025 in the US.54 Further, a report by IQVIA Institute for Human Data Science on biosimilars in the US projected an increased savings of $181 billion in 2023-2027, which will be more than 4 times the savings over the past 5 years ($40 billion), as newly approved biosimilars launch and existing biosimilars see continued uptake and price reduction.42 However, the potential role of biosimilars and their contribution to the health care system will not be realized until more policy makers and physicians support biosimilar usage by understanding their value proposition. In general, biosimilars are equally efficacious, offer the same dosing approach and schedule as reference medicines, and have potential to increase access while delivering cost savings in the US.

Limitations

The results of this economic model are meant to provide an estimate of the potential costs that can be incurred and the savings realized from the perspective of a commercial health plan with the inclusion of biosimilar NTZ. Actual savings experienced by health plans will depend on their unique circumstances such as their covered population, treatment utilization rates, and pharmacy and medical costs.

Our analysis did not take OOP maximums into consideration due to the wide variation in plan designs. Patients receiving care out of network are likely to have much higher OOP thresholds. Similarly, patients on original Medicare55 who have 20% Part B coinsurance without annual patient cost-sharing limits can benefit from the reduced drug price and resulting reduced co-pay for biosimilars. Additionally, we also did not assess the impact of potential deductibles, manufacturers’ co-pay assistance, or co-pay cards for commercially insured patients. We excluded these parameters because of the complexity and variety of payer and manufacturer benefit structures across the US.

The model assumed that patients starting alemtuzumab would stay on treatment for the rest of the model’s time horizon. However, this assumption did not have any significant impact on the results because alemtuzumab market share was assumed unchanged in both analysis scenarios. Real-world dosing patterns utilized in the base-case scenario were derived from the included studies but can still vary in other real-world settings. We also did not account for use of ofatumumab (not infused but high efficacy) or off-label rituximab, which is considerably less expensive.

Because biosimilar NTZ had not launched in the US at the time of this analysis, the price is currently an assumption based on historical market trends, and the base case price differential represents the most conservative scenario.36 The model assumed that the utilization of NTZ remained stable over the 3 years. Utilization rates were based on multiple references describing the proportion of patients treated with various DMTs. Some of the references may not reflect the current treatment population count, and individual payer utilization rates may be different.

CONCLUSIONS

Based on this 3-year analysis, the use of biosimilar NTZ is economically attractive and can potentially address high spending and access barriers to high-efficacy DMTs. Assuming a reduction in price, the value proposition of NTZ is expected to improve. Future analyses should be continually conducted to assess whether these short-term financial benefits can translate into more cost-effective care, increased access and earlier adoption of NTZ, and improved population-based outcomes.

Acknowledgments

All authors approved the final version of the manuscript and thank Nidhi Arora, PhD, of Sandoz Pvt Ltd in Hyderabad, India, for medical writing support.

Author Affiliations: Sandoz Inc (EL, AC), Princeton, NJ; Novartis Corporation Sdn Bhd (AG), Selangor, Malaysia; Novartis Healthcare Pvt Ltd (SG), Hyderabad, India; Sandoz International GmbH (MS), Holzkirchen, Germany; College of Pharmacy, Oregon State University (DMH), Portland, OR.

Source of Funding: This study was funded by Sandoz International GmbH.

Author Disclosures: Dr Li is employed by Sandoz and owns stock in Novartis. Mr Goh and Ms Gupta are employed by Novartis. Ms Schauf is employed by Sandoz International. Dr Chen is employed by and owns stock in Sandoz. Dr Hartung has consulted for the National Multiple Sclerosis Society and has provided expert testimony in litigation on behalf of Humana and the US Department of Justice.

Authorship Information: Concept and design (EL, AG, SG, MS, AC, DMH); acquisition of data (AG, SG); analysis and interpretation of data (EL, AG, SG, AC, DMH); drafting of the manuscript (EL, AC); critical revision of the manuscript for important intellectual content (AG, SG, MS, AC, DMH); statistical analysis (AG, SG); administrative, technical, or logistic support (AC); and supervision (MS).

Address Correspondence to: Anna Chen, PharmD, MS, Sandoz Inc, 100 College Rd W, Princeton, NJ 08540. Email: anna-1.chen@sandoz.com.

REFERENCES

1. Reich DS, Lucchinetti CF, Calabresi PA. Multiple sclerosis. N Engl J Med. 2018;378(2):169-180. doi:10.1056/NEJMra1401483

2. Wallin MT, Culpepper WJ, Campbell JD, et al; US Multiple Sclerosis Prevalence Workgroup. The prevalence of MS in the United States: a population-based estimate using health claims data. Neurology. 2019;92(10):e1029-e1040. doi:10.1212/WNL.0000000000007035

3. Walton C, King R, Rechtman L, et al. Rising prevalence of multiple sclerosis worldwide: insights from the Atlas of MS, third edition. Mult Scler. 2020;26(14):1816-1821. doi:10.1177/1352458520970841

4. Koch-Henriksen N, Magyari M. Apparent changes in the epidemiology and severity of multiple sclerosis. Nat Rev Neurol. 2021;17(11):676-688. doi:10.1038/s41582-021-00556-y

5. Atlas of MS, 3rd Edition: Part 1: Mapping Multiple Sclerosis Around the World. Multiple Sclerosis International Federation. September 20, 2020. Accessed December 21, 2023. https://www.msif.org/wp-content/uploads/2020/12/Atlas-3rd-Edition-Epidemiology-report-EN-updated-30-9-20.pdf

6. Multiple sclerosis: symptoms & causes. Mayo Clinic. Updated December 24, 2022. Accessed December 21, 2023. https://www.mayoclinic.org/diseases-conditions/multiple-sclerosis/symptoms-causes/syc-20350269

7. Dilokthornsakul P, Valuck RJ, Nair KV, Corboy JR, Allen RR, Campbell JD. Multiple sclerosis prevalence in the United States commercially insured population. Neurology. 2016;86(11):1014-1021. doi:10.1212/wnl.0000000000002469

8. Lo J, Chan L, Flynn S. A systematic review of the incidence, prevalence, costs, and activity and work limitations of amputation, osteoarthritis, rheumatoid arthritis, back pain, multiple sclerosis, spinal cord injury, stroke, and traumatic brain injury in the United States: a 2019 update. Arch Phys Med Rehabil. 2021;102(1):115-131. doi:10.1016/j.apmr.2020.04.001

9. Langer-Gould AM, Gonzales EG, Smith JB, Li BH, Nelson LM. Racial and ethnic disparities in multiple sclerosis prevalence. Neurology. 2022;98(18):e1818-e1827. doi:10.1212/WNL.0000000000200151

10. Goldenberg MM. Multiple sclerosis review. P T. 2012;37(3):175-184.

11. Polman CH, O’Connor PW, Havrdova E, et al; AFFIRM Investigators. A randomized, placebo-controlled trial of natalizumab for relapsing multiple sclerosis. N Engl J Med. 2006;354(9):899-910. doi:10.1056/NEJMoa044397

12. Rudick RA, Stuart WH, Calabresi PA, et al; SENTINEL Investigators. Natalizumab plus interferon beta-1a for relapsing multiple sclerosis. N Engl J Med. 2006;354(9):911-923. doi:10.1056/NEJMoa044396

13. Olofsson S, Wickström A, Häger Glenngård A, Persson U, Svenningsson A. Effect of treatment with natalizumab on ability to work in people with multiple sclerosis: productivity gain based on direct measurement of work capacity before and after 1 year of treatment. BioDrugs. 2011;25(5):299-306. doi:10.2165/11593770-000000000-00000

14. Kamat SA, Rajagopalan K, Stephenson JJ, Agarwal S. Impact of natalizumab on patient-reported outcomes in a clinical practice setting: a cross-sectional survey. Patient. 2009;2(2):105-112. doi:10.2165/01312067-200902020-00006

15. Samjoo IA, Worthington E, Drudge C, et al. Efficacy classification of modern therapies in multiple sclerosis. J Comp Eff Res. 2021;10(6):495-507. doi:10.2217/cer-2020-0267

16. Bebo B, Cintina I, LaRocca N, et al. The economic burden of multiple sclerosis in the United States. Neurology. 2022;98(18):e1810. doi:10.1212/WNL.0000000000200150

17. Prime’s analytics uncovers the hidden ups and downs behind the flat drug trend for MS DMDs. Prime Therapeutics. August 1, 2021. Accessed December 21, 2023. https://www.primetherapeutics.com/news/primes-analytics-uncovers-the-hidden-ups-and-downs-behind-the-flat-drug-trend-for-ms-dmds/

18. Simacek K, Ko J, Moreton D, Varga S, Johnson K, Katic BJ. The impact of disease-modifying therapy access barriers on people with multiple sclerosis: mixed-methods study. J Med Internet Res. 2018;20(10):e11168. doi:10.2196/11168

19. Greenberg B, Hall S, Grabner M, Balu S, Zhang X, Kantor D. Multiple sclerosis relapse rates and healthcare costs of two versions of glatiramer acetate. Curr Med Res Opin. 2020;36(7):1167-1175. doi:10.1080/03007995.2020.1760808

20. Biosimilar medicines generated $7 billion in savings in 2021. News release. Biosimilars Council. September 21, 2022. Accessed December 21, 2023. https://biosimilarscouncil.org/news/biosimilar-medicines-generated-7-billion-in-savings-in-2021/

21. FDA approves first biosimilar to treat multiple sclerosis. News release. FDA. August 24, 2023. Accessed April 24, 2024. https://www.fda.gov/news-events/press-announcements/fda-approves-first-biosimilar-treat-multiple-sclerosis

22. Hemmer B, Wiendl H, Roth K, et al. Efficacy and safety of proposed biosimilar natalizumab (PB006) in patients with relapsing-remitting multiple sclerosis: the Antelope phase 3 randomized clinical trial. JAMA Neurol. 2023;80(3):298-307. doi:10.1001/jamaneurol.2022.5007

23. Caro JJ, Briggs AH, Siebert U, Kuntz KM; ISPOR-SMDM Modeling Good Research Practices Task Force. Modeling good research practices—overview: a report of the ISPOR-SMDM Modeling Good Research Practices Task Force—1. Value Health. 2012;15(6):796-803. doi:10.1016/j.jval.2012.06.012

24. Mauskopf JA, Sullivan SD, Annemans L, et al. Principles of good practice for budget impact analysis: report of the ISPOR Task Force on good research practices—budget impact analysis. Value Health. 2007;10(5):336-347. doi:10.1111/j.1524-4733.2007.00187.x

25. Zhang Y, Salter A, Jin S, et al. Disease-modifying therapy prescription patterns in people with multiple sclerosis by age. Ther Adv Neurol Disord. 2021;14:17562864211006499. doi:10.1177/17562864211006499

26. Elsisi Z, Hincapie AL, Guo JJ. Expenditure, utilization, and cost of specialty drugs for multiple sclerosis in the US Medicaid population, 2008-2018. Am Health Drug Benefits. 2020;13(2):74-84.

27. Romero-Pinel L, Bau L, Matas E, et al. The age at onset of relapsing-remitting multiple sclerosis has increased over the last five decades. Mult Scler Relat Disord. 2022;68:104103. doi:10.1016/j.msard.2022.104103

28. Nazareth TA, Rava AR, Polyakov JL, et al. Relapse prevalence, symptoms, and health care engagement: patient insights from the Multiple Sclerosis in America 2017 survey. Mult Scler Relat Disord. 2018;26:219-234. doi:10.1016/j.msard.2018.09.002

29. Kern DM, Cepeda MS. Treatment patterns and comorbid burden of patients newly diagnosed with multiple sclerosis in the United States. BMC Neurol. 2020;20(1):296. doi:10.1186/s12883-020-01882-2

30. Nicholas J, Halpern R, Ziehn M, Peterson-Brandt J, Leszko M, Deshpande C. Real-world cost of treatment for multiple sclerosis patients initiating and receiving infused disease-modifying therapies per recommended label in the United States. J Med Econ. 2020;23(8):885-893. doi:10.1080/13696998.2020.1761821

31. Zhovtis Ryerson L, Frohman TC, Foley J, et al. Extended interval dosing of natalizumab in multiple sclerosis. J Neurol Neurosurg Psychiatry. 2016;87(8):885-889. doi:10.1136/jnnp-2015-312940

32. Ryerson LZ, Foley J, Chang I, et al. Risk of natalizumab-associated PML in patients with MS is reduced with extended interval dosing. Neurology. 2019;93(15):e1452-e1462. doi:10.1212/WNL.0000000000008243

33. IBM Redbooks. MicroMedex Solutions. Accessed November 8, 2022. https://www.micromedexsolutions.com/

34. Duff S, Bargiacchi F, Norregaard C, Brener M, Sullivan E. The budget impact of adding pralsetinib to a US health plan formulary for treatment of non-small cell lung cancer and thyroid cancer with RET alterations. J Manag Care Spec Pharm. 2022;28(2):218-231. doi:10.18553/jmcp.2021.21308

35. Kongnakorn T, Bharmal M, Kearney M, et al. Budget impact of including avelumab as a second-line treatment for locally advanced or metastatic urothelial cancer in the United States: commercial and Medicare payer perspectives. Clinicoecon Outcomes Res. 2019;11:659-672. doi:10.2147/CEOR.S215069

36. 2021 Biosimilar Trends Report: Current State of the Marketplace. Amgen Inc. 2021. Accessed December 21, 2023. https://www.amgenbiosimilars.com/bioengage/-/media/Themes/Amgen/amgenbiosimilars-com/Amgenbiosimilars-com/pdf/USA-CBU-80961_Amgen-Biosimilars-Trend-Report.pdf

37. Kozma CM, Roberts NL, Phillips A. PND4 real-world costs of administering disease modifying drug infusions among patients with multiple sclerosis: a US retrospective administrative claims database analysis. Value Health. 2020;23(suppl 1):S258. doi:10.1016/j.jval.2020.04.897

38. Chirikov V, Ma I, Joshi N, et al. Cost-effectiveness of alemtuzumab in the treatment of relapsing forms of multiple sclerosis in the United States. Value Health. 2019;22(2):168-176. doi:10.1016/j.jval.2018.08.011

39. Oleen-Burkey M, Castelli-Haley J, Lage MJ, Johnson KP. Burden of a multiple sclerosis relapse: the patient’s perspective. Patient. 2012;5(1):57-69. doi:10.2165/11592160-000000000-00000

40. Disease-Modifying Therapies for Relapsing-Remitting and Primary-Progressive Multiple Sclerosis: Effectiveness and Value Final Evidence Report. Institute for Clinical and Economic Review. March 6, 2017. Accessed December 21, 2023. https://icer.org/wp-content/uploads/2020/10/CTAF_MS_Final_Report_030617.pdf

41. Consumer price indices (CPIs) - complete database. Organisation for Economic Co-Operation and Development. Accessed December 21, 2023. https://stats.oecd.org/Index.aspx?DataSetCode=PRICES_CPI

42. Biosimilars in the United States 2023-2027: Competition, Savings, and Sustainability. IQVIA Institute for Human Data Science. January 2023. Accessed December 21, 2023. https://www.iqvia.com/insights/the-iqvia-institute/reports-and-publications/reports/biosimilars-in-the-united-states-2023-2027

43. The U.S. Generic & Biosimilar Medicines Savings Report. Association for Accessible Medicines. September 2023. Accessed December 21, 2023. https://accessiblemeds.org/sites/default/files/2023-09/AAM-2023-Generic-Biosimilar-Medicines-Savings-Report-web.pdf

44. Filippi M, Amato MP, Centonze D, et al. Early use of high-efficacy disease‑modifying therapies makes
the difference in people with multiple sclerosis: an expert opinion. J Neurol. 2022;269(10):5382-5394. doi:10.1007/s00415-022-11193-w

45. Himmelstein DU, Thorne D, Warren E, Woolhandler S. Medical bankruptcy in the United States, 2007: results of a national study. Am J Med. 2009;122(8):741-746. doi:10.1016/j.amjmed.2009.04.012

46. Sadigh G, Switchenko J, Lava N, et al. Longitudinal changes of financial hardship in patients with multiple sclerosis. Mult Scler Relat Disord. 2021;53:103037. doi:10.1016/j.msard.2021.103037

47. Hartung DM, Johnston KA, McGregor JC, Bourdette DN. Characteristics of prescription drug use among individuals with multiple sclerosis in the US Medicare population. Int J MS Care. 2022;24(2):90-97. doi:10.7224/1537-2073.2021-062

48. Hartung DM, Johnston KA, Bourdette DN, Chen R, Tseng CW. Closing the Part D coverage gap and out-of-pocket costs for multiple sclerosis drugs. Neurol Clin Pract. 2021;11(4):298-303. doi:10.1212/CPJ.0000000000000929

49. Hartung DM, Johnston KA, Irwin A, Markwardt S, Bourdette DN. Trends in coverage for disease-modifying therapies for multiple sclerosis in Medicare Part D. Health Aff (Millwood). 2019;38(2):303-312. doi:10.1377/hlthaff.2018.05357

50. San-Juan-Rodriguez A, Good CB, Heyman RA, Parekh N, Shrank WH, Hernandez I. Trends in prices, market share, and spending on self-administered disease-modifying therapies for multiple sclerosis in Medicare Part D. JAMA Neurol. 2019;76(11):1386-1390. doi:10.1001/jamaneurol.2019.2711

51. Callaghan BC, Reynolds E, Banerjee M, et al. Out-of-pocket costs are on the rise for commonly prescribed neurologic medications. Neurology. 2019;92(22):e2604-e2613. doi:10.1212/WNL.0000000000007564

52. 2022 Biosimilars Report: The U.S. Journey and Path Ahead. Cardinal Health. 2022. Accessed December 21, 2023. https://www.cardinalhealth.com/content/dam/corp/web/documents/Report/cardinal-health-2022-biosimilars-report.pdf

53. Study finds U.S. generic and biosimilar savings totaled a record $338 billion in 2020. News release. Association for Accessible Medicines. September 21, 2021. Accessed December 25, 2023. https://accessiblemeds.org/resources/press-releases/study-finds-us-generic-and-biosimilar-savings-totaled-record-338-billion

54. Mulcahy A, Buttorff C, Finegold K, et al. Projected US savings from biosimilars, 2021-2025. Am J Manag Care. 2022;28(7):329-335. doi:10.37765/ajmc.2022.88809

55. Costs. Medicare.gov. Accessed December 25, 2023. https://www.medicare.gov/basics/costs/medicare-costs