Multiple Sclerosis Medications in the VHA: Delivering Specialty, High-Cost, Pharmacy Care in a National System
Introduction/Importance: Pharmacotherapy for multiple sclerosis has increased significantly since 1993 when the first disease modifying therapy was approved. The expansion of therapies has been accompanied with differences in adverse effect profiles, efficacy, and cost. The most recent therapies pose the challenge of balancing these issues while providing optimal care.
Observations: Several measures such as generic conversion and standardization of therapies can be employed to control costs of therapy. The safety and efficacy of these agents can be monitored by implementation of criteria for use and/or medication utilization evaluations.
Conclusions: A formulary management system encompasses methodologies to evaluate the relevant clinical and medical literature and includes a systematic approach for selecting medications for different diseases, conditions, and patients. Formulary systems often contain prescribing guidelines and clinical recommendations that assist health care professionals with providing high quality, value-based care for patients.
Factors Impacting DMT Use
Recent changes to MS typing have impacted utilization of DMTs. Traditionally, there were 4 subtypes of MS: relapsing remitting (RRMS), secondary progressive (SPMS), progressive relapsing (PRMS), and primary progressive (PPMS). These subtypes are now viewed more broadly and grouped as either relapsing or progressive. The traditional subtypes fall under these broader definitions. Additionally, SPMS has been broken into active SPMS, characterized by continued worsening of disability unrelated to acute relapses, superimposed with activity that can be seen on magnetic resonance images (MRIs), and nonactive SPMS, which has the same disability progression as active SPMS but without MRI-visible activity.4-6 In 2019, these supplementary designations to SPMS made their first appearance in FDA-approved indications. All existing DMTs now include this terminology in their labelling and are indicated in active SPMS. There remain no DMTs that treat nonactive SPMS.
The current landscape of DMTs is highly varied in method of administration, risks, and benefits. As efficacy of these medications often is marked by how well they can prevent the immune system from attacking myelin, an inverse relationship between safety and efficacy results. The standard treatment outcomes in MS have evolved over time. The following are the commonly used primary outcomes in clinical trials: relapse reduction; increased time between relapses; decreased severity of relapses; prevention or extend time to disability milestones as measured by the Expanded Disability Status Scale (EDSS) and other disability measures; prevention or extension of time to onset of secondary progressive disease; prevention or reduction of the number and size of new and enhancing lesions on MRI; and limitation of overall MRI lesion burden in the central nervous system (CNS).
Newer treatment outcomes employed in more recent trials include: measures of axonal damage, CNS atrophy, evidence of microscopic disease via conventional MRI and advanced imaging modalities, biomarkers associated with inflammatory disease activity and neurodegeneration in MS, and the use of no evidence of disease activity (NEDA). These outcomes also must be evaluated by the safety concerns of each agent. Short- and long-term safety are critical factors in the selection of DMTs for MS. The injectable therapies for MS (interferon β‐1a, interferon β‐1b, and GA) have established long-term safety profiles from > 20 years of continuous use. The long-term safety profiles of oral immunomodulatory agents and monoclonal antibodies for these drugs in MS have yet to be determined. Safety concerns associated with some therapies and added requirements for safety monitoring may increase the complexity of a therapeutic selection.
Current cost minimization strategies for DMT include limiting DMT agents on formularies, tier systems that incentivize patients/prescribers to select the lowest priced agents on the formulary, negotiating arrangements with manufacturers to freeze prices or provide discounts in exchange for a priority position in the formulary, and requiring prior authorization to initiate or switch therapy. The use of generic medications and interchange to these agents from a brand name formulation can help reduce expense. Several of these strategies have been implemented in VHA.
Disease-Modifying Therapies
In 2019, 18,645 veterans with MS had either a MS-specific DMT or ≥ 1 annual encounters with a primary diagnosis of MS. Of this population, 4,720 were female and 13,357 were service connected according to VA data. About 50% of veterans with MS take a DMT. This percentage has remained stable over the past decade (Table 2). Although it appears the number of unique veterans prescribed an outpatient DMT is decreasing, this does not include the growing use of infused DMTs or DMTs obtained through the Veterans Choice Program (VCP)/Community Care (CC).
