LYON, FRANCE—Patients with multiple sclerosis (MS) may have stronger preferences for drugs that prevent long-term disability progression or MRI changes than for drugs that prevent relapses, researchers reported at the 28th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS). Preventing relapses, however, is the most common outcome in clinical trials. Patients with MS also may prefer drugs that substantially improve how they feel, but this criterion is not an efficacy outcome of MS drugs.
Leslie S. Wilson, PhD, Professor of Clinical Pharmacy at the University of California, San Francisco, and colleagues found that a 30% risk of fatal side effects had a larger negative effect on patient preference than any other characteristic of a hypothetical drug. In addition, patients preferred once daily oral drug administration to all other routes and frequencies of injection.
Rating Hypothetical Drugs
To understand patient preferences for the risks and benefits of hypothetical disease-modifying therapies (DMTs), Dr. Wilson and her team administered a card-sort conjoint analysis survey and paper questionnaire to 50 adult patients with relapsing-remitting MS. The investigators created the cards using a fractional factorial design, and each card contained eight attributes, including “Improve Symptoms,” “Common Side Effects,” “Severe Side Effects,” “Administration,” and “Time on Market.” Each attribute was assigned one of four levels of risks and benefits. Patients rated 16 hypothetical DMTs and their current therapies by placing the corresponding cards on a number line that stretched from zero, which represented a “not acceptable” rating, to 10, which represented a “most favorable” rating.
Women accounted for 74% of the sample population, (mean age, 43). Approximately 74% of participants were Caucasian, 10% were Hispanic or Latino, and 16% were other ethnicities. A plurality of the patients (34%) took glatiramer acetate, 26% took interferons, 18% took no DMT, 12% took natalizumab, and 10% took another drug.
Risk of Fatal Side Effects Decreased Patient Preference Ratings
Patients rated a hypothetical drug 12% higher for each year that it prevented disability progression. All levels of subjective symptom improvement were preferred to no improvement. Patients also preferred hypothetical DMTs that prevented MRI changes for one additional year.
Every 1% increase in the risk of fatal side effects decreased patients’ preference ratings by 11%. Among nonfatal side effects, only mood or vision changes decreased patient preference. Preventing relapses and time on market were not associated with patient preference.
Results of this study were used to create a choice-based conjoint survey, standard gamble, and revised questionnaire for a larger study, said Dr. Wilson. The new study will “enable maximum acceptable risks to be calculated, further elucidating DMT preference and setting groundwork for improved patient-centered choices in the future,” she concluded.
—Erik Greb