OBJECTIVES: Progressive multifocal leukoencephalopathy (PML) is a rare but fatal opportunistic infection caused by reactivation of latent JC polyomavirus (JCV). It mainly occurs in individuals with immunosuppressive conditions. The objective of our analysis aims to characterise the overall survival (OS) of individuals diagnosed with PML.

METHODS: Patient-level data pertaining to individuals diagnosed with PML were obtained via extracting data from case studies identified via a comprehensive systematic literature review (SLR), which was performed in October 2023. The duration from symptom onset to diagnosis and overall survival post-diagnosis were assessed using Kaplan-Meier methods to evaluate survival outcomes.

RESULTS: In total, 323 individuals with PML were included in the analysis (36% female, 57% male, 7% sex not reported). Median age (min, max) at symptom onset (n=224) and at death (n=323) was 54.7 (5.96, 86.9) and 58.0 (13.1, 87.1) years, respectively. Median time from symptom onset to PML diagnosis was 1.4 months (95% CI, 1-2). Median time from diagnosis to death was 21 months (95% CI, 10.2 - NA). Differences, though not significant, were observed in the median time from symptom onset to diagnosis between regions ranging from 1.0 months (95% CI, 0.96-1.44) in the Americas to 2.04 months (95% CI, 1.56-3.00) in the Western Pacific with time from diagnosis to death ranging from 1.0 months (1.0, NA) in the Eastern Mediterranean region to 21.0 months (7.9, NA) in Europe. Publication bias in source data was a possible limitation.

CONCLUSIONS: The reduced survival of individuals with PML indicates a high disease burden, unmet need for treatment/treatment guidance and clinical management for PML. The relatively long time from symptom onset to diagnosis demonstrates a need for earlier diagnosis/ detection.