Real World Adherence to and Persistence With Oral Oncolytics in Multiple Myeloma: A Systematic Review and Meta-analysis

Introduction: Oral oncolytic treatments (OOTs) have improved the prognosis of patients with multiple myeloma (MM). However, the effectiveness of these therapies is undermined by poor adherence. We aimed to characterize the real-world adherence to, and persistence with, OOTs for MM.

Materials and methods: MEDLINE, EMBASE, and the International Pharmaceutical abstracts databases were searched for relevant observational studies published in English up to November 21, 2021. This was supplemented by manual searches of abstracts from the annual meetings of the American Society of Hematology, the American Society for Clinical Oncology, and the European Hematology Association as well as screening the references of included articles. Random-effects meta-analysis was performed.

Results: Following screening of 11,557 articles, 19 studies involving 27,129 patients in 8 countries (France, the US, Germany, Italy, the UK, Brazil, South Korea, and Belgium) prescribed OOTs (lenalidomide, thalidomide, pomalidomide, panobinostat, ixazomib, and melphalan) for MM were included. The overall pooled proportion of adherent patients was 67.9% (95% confidence interval [CI]: 57.1%-77.8%). The pooled proportion of adherent patients was higher in self-reported questionnaire-based studies compared to those using prescription/dispensing data (81.6% vs. 61.0%; P-value for difference = .08). Across 5 studies involving 15,363 patients, a pooled proportion of 35.8% (95% CI: 22.0-50.9) discontinued treatment. Factors reported to be associated with nonadherence included increasing age, higher comorbidity, polypharmacy, and a lack of social support.

Conclusion: In patients with MM, adherence to and persistence with OOTs remains suboptimal. To achieve desired clinical outcomes, interventions to improve adherence and minimize discontinuation may be warranted.