Seventy-nine percent of patients with progressive multifocal leukoencephalopathy may have experienced clinical improvement following receipt of directly isolated allogeneic virus-specific T cells, according to a recent study.

Progressive multifocal leukoencephalopathy (PML) poses therapeutic challenges as a result of the absence of approved antiviral treatments.

In a recent retrospective case series, published in JAMA Neurology, researchers investigated the efficacy of directly isolated allogeneic virus-specific (DIAVIS) T cells in 28 patients with PML. The objective was to enhance immune function by using T cells that target the BK polyomavirus, which is associated with PML.

The study was conducted at Hannover Medical School between March 2020 and February 2022. The average age of participants in the study was 60 years, with 71.4% of the cohort being male (20 males and 8 females). DIAVIS T cells were administered within approximately 24 hours of isolation from healthy donors, which reduced the treatment initiation time compared with previous methodologies.

The findings indicated that 79% (n = 22) of the patients exhibited a clinical response following treatment, characterized by stabilization or improvement of neurologic symptoms and a reduction in viral load. Survival analysis revealed a statistically significant increase in 12-month survival rates among patients receiving DIAVIS T-cell therapy compared with historical controls receiving best supportive treatment (BST). Specifically, 69% of the patients treated with DIAVIS T cells survived at least 12 months postdiagnosis compared with a 50% survival rate among the patients in the BST group. The hazard ratio, indicating better survival among patients treated with DIAVIS T cells vs those receiving BST, was 0.42, with a 95% confidence interval of 0.24 to 0.73 and a P-value of .02.

While this case series provided data regarding the efficacy of DIAVIS T cell therapy for survival and functional outcomes in patients with PML, it acknowledged limitations, including the lack of stringent inclusion criteria. 

Full disclosures can be found in the published study.