Cytheris' combinational therapy demonstrates possible therapeutic strategy for PML

Nov 30 2010

Cytheris SA, a clinical-stage biopharmaceutical company focused on research and development of new therapies for immune modulation, today announced the publication of a case study report based on successful treatment of Progressive Multifocal Leukoencephalopathy (PML) with combination therapy consisting of two investigational agents, Cytheris' recombinant human interleukin-7 (CYT107) and CMX001, an investigational, oral broad-spectrum antiviral drug (Chimerix, Research Triangle Park, NC) in the Journal of Antimicrobial Chemotherapy. The combination therapy succeeded in eradicating the polyomavirus JC, the virus that causes PML, in less than two weeks following initiation of CYT107 treatment, and four weeks following the introduction of CMX001.

“To my knowledge, this is the first case report to demonstrate the use of combination therapy, in this instance two investigational medications, as a possible therapeutic strategy for the treatment of PML.”

Progressive Multifocal Leukoencephalopathy (PML) is a rare and usually fatal neurological disease caused by the polyomavirus JC. The virus, first identified in 1971, multiplies in and destroys oligodendrocytes, which are cells of the brain that produce the myelin sheath surrounding neurons. Symptoms include loss of vision, impaired speech, paralysis, cognitive decline and weakness. There is no known cure for PML.

"The combination of CYT107 with a powerful antiviral agent to treat PML follows the same therapeutic regimen that Cytheris is investigating in clinical studies of HCV and HBV, where interferon or antiviral therapy is employed to drop the viral load and is then followed by added treatment with CYT107 to clear the virus, a process accompanied by an increase in CD4 and CD8 T cell counts", said Michel Morre, DVM, President and Chief Executive Officer of Cytheris. "In responding patients, comparison of the resulting trend lines in decreased viral load and increased CD4 count over time shows an almost identical pattern when the PML case described in Dr. Patel's report is compared to CYT107-treated patients who have cleared the HCV virus. We believe the same pattern will soon emerge as we reach the higher dose range in our HBV CONVERT study, currently being conducted in France and Italy."

The paper, "A case of progressive multifocal leukoencephalopathy and idiopathic CD4+ lymphocytopenia," published in the Journal of Antimicrobial Chemotherapy (Patel A, et al, 2010, Dec., Vol. 65(12): 2489-92), is a case study that provides an overview of the treatment of a single adult patient with PML, a rare and usually fatal disease caused by the human polyomavirus JC. The patient, an adult female admitted to The Methodist Hospital, Houston, Texas, was treated by a medical team under the direction of Julie Y. Patel, MD, of the Immunology, Allergy & Rheumatology Department of Texas A&M Health Science Center College of Medicine.

"Though both experiential and experimental data in the treatment of PML have grown quite considerably in recent years, it is important to keep in mind that there still are no known interventions that can reliably prevent or adequately treat PML", stated Dr. Patel. "To my knowledge, this is the first case report to demonstrate the use of combination therapy, in this instance two investigational medications, as a possible therapeutic strategy for the treatment of PML."