Do injectable MS drugs still have a role?


This year marks the 25th anniversary of the publication of the Betaseron phase III study (Interferon-beta MS Study Group. Neurology 1993;43:655-661), which ushered in the era of disease-modifying therapies in the treatment of multiple sclerosis. In the usual course of things, first-generation agents – especially drugs administered by injection – would be superseded by novel therapies, either a more convenient oral agent (fingolimod, teriflunomide, dimethyl fumarate, cladribine) or a more potent infusion drug (natalizumab, alemtuzumab, ocrelizumab). Market shares have shifted but all treatments remain available, resulting in the present state of a surprisingly lengthy list of options. This raises the questions: are so many medications needed, and what is the role of injectable agents in MS management?

To address these questions from a patient’s perspective, MSology, a patient website that attracts about 45,000 page-views per year (and is the sister site of NeuroSens), posted a series of questionnaires over the past year to examine patients’ experience with current therapies, treatment preferences and overall satisfaction with their medication. The cumulative number of survey respondents was 507.

Respondents were generally older: in the Great MS Meds survey (n=388), 72% of the sample were aged >41 years. A majority had been living with MS for 6-10 years (20%) or 11-20 years (32%). However, 71% said they had been on treatment for < 5 years, suggesting that a delay in treatment initiation is not uncommon. This may be due to a lack of perceived need earlier in the disease course: 63% of respondents in their twenties reported being on a treatment compared to 76% in their forties and 87% of those  aged >50 years.

While most MS patients reported taking an oral DMT, 40% of the sample were currently taking an injectable medication. In the subgroup of patients currently on a beta-interferon agent, 40% said they had been taking the drug for fewer than five years, indicating that physicians continue to prescribe interferons despite the other options available. In this sample, the most commonly-used interferon was intramuscular beta-interferon-1a.

The greatest preference among MS patients was for an oral DMT, which was generally perceived to be more convenient than an injectable. A separate survey (n=39) examined trade-offs of benefits and risks. Given the choice of one pill a day or one injection a day, 96% of respondents preferred an oral. However, the frequency of administration and side effect burden influenced the perceived convenience. Overall, 25% said they would prefer less frequent dosing (either a once-weekly injection, a once-monthly infusion or annual infusions) rather than a once-daily oral medication. Given the choice of more frequent dosing (e.g. once-daily vs. once-weekly) and less frequent side effects (twice a month vs. 7 times a month), all respondents chose the regimen with less frequent side effects. Preferences also differed if the oral created more of a side effect burden: 61% said they would prefer a less frequent injection (once a week) with fewer side effects (twice a month) compared to a once-daily oral with more side effects (7 times a month). Similarly, when comparing oral and infusion drugs, a majority of respondents preferred the drug with less frequent side effects regardless of the route of administration.

Numerous studies have reported on patients’ treatment satisfaction. In the MSology survey (n=32), respondents were satisfied with their current DMT – no matter what they were taking. Average satisfaction ratings were similar for DMF (8.1 out of 10), beta-interferon-1a IM (7.7), glatiramer acetate (7.6) and beta-interferon-1a SC (7.5). This suggests a survivor effect: people are currently taking a medication because they are satisfied; the dissatisfied have discontinued. In a similar vein, most patients stated that their current regimen provided the optimal route of administration and dosing frequency for their needs. Satisfaction ratings were higher when patients perceived that they, rather than the clinician, had made the final treatment decision. Interestingly, among patients who stated that 100% of the treatment decision had been theirs, a majority (66%) opted for beta-interferon-a IM.

Why are injectable drugs still prescribed? One factor appears to be the patient’s weighing of risk-benefit. When asked to compare injectable and oral agents, only 6% of respondents thought that oral therapies were more efficacious than an injectable; 58% perceived that the efficacy of orals and injectables was comparable. With regard to the side effect burden, 20% felt that oral therapies were less burdensome, and 63% thought that the burden was comparable with an oral and an injectable.

These results suggest that injectables continue to have a role as platform therapies, and are an acceptable option for patients who are concerned with the side-effect profile of oral agents, or who want a less frequent dosing schedule.

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