High levels of adherence to oral immunomodulatory therapy were observed in a prospective study of patients with multiple myeloma based on 2 indirect measures of medication adherence. The findings from this study were published in PLoS One.
The oral immunomodulatory agents lenalidomide, thalidomide, and pomalidomide are commonly incorporated into the treatment regimens for patients with multiple myeloma, and may be taken over long-term periods. Adherence to these agents is a critically important component of treatment effectiveness. However, given their high costs, financial toxicity is a potential adverse event associated with use of these agents.
For this study, the researchers used 2 indirect measures to determine medication adherence: a questionnaire consisting of 10 questions requiring yes or no responses and the Medication Possession Ratio (MPR), which was calculated as the ratio of the total days’ supply of immunomodulatory agents dispensed divided by the number of days between the first dispensation and the end of the last dispensation. According to the MPR, a fully adherent patient would achieve a score of 1; in this study, a score 0.90 or higher was considered to represent adherence. As this study was conducted in France, the MPR was a useful tool for assessment of adherence since all of these immunomodulatory drugs are dispensed by hospital pharmacies.
The adherence questionnaire included questions related to whether the index medication was taken that morning, whether the patient had run out of the index medication since the last visit, took it later than prescribed, if the patient feels worse on the index medication, forgets to take the medication, whether they feel they take too many medications, know the name of their medications, stop taking the index medication when they feel sick, whether a change in daily routine affects how they take the medication, and whether they sometimes skip the medication when they feel better.
Patients received 1 point for each “no” answer, except for the question related to the name of their medications for which they received 1 point for a “yes” response. A fully adherent patient would achieve a score of 10 on the questionnaire, with a score of 8 or higher considered to represent adherence.
Study participants were 63 consecutive patients with multiple myeloma treated at a single institution who received 2 or more consecutive dispensations of an immunomodulatory drug between March 1, 2016, and May 15, 2016. The median number of cycles was 4, and lenalidomide was prescribed for 54% of participants. More than half of patients had either been previously treated with another immunomodulatory drug or had been on the current immunomodulatory drug for 6 months or longer.
Participants achieved a mean score of 8.2 on the questionnaire, indicating 76% were adherent to study medication, and a mean score of 0.97 on the MPR, indicating 94% were adherent. When both measures were considered, adherence was 70%. However, results obtained using the questionnaire score were not concordant with the MPR score; nor was age, gender, or number of lines of treatment associated with questionnaire score. The lack of association between results obtained with the questionnaire and the MPR led the researchers to recommend using the questionnaire with caution.
Cransac A, Aho S, Chretien M-L, et al. Adherence to immunomodulatory drugs in patients with multiple myeloma [published online March 27, 2019]. PLoS One. doi: 10.1371/journal.pone.0214446