(ChemotherapyAdvisor) – Treating patients with chronic lymphocytic leukemia (CLL) with a proprietary extract of Panax quinquefolius, CVT-E002, resulted in a trend toward reduced rates of moderate to severe acute respiratory illness (ARI); however, the agent did not significantly reduce ARI days or antibiotic use, according to a study in the September/October issue of the Journal of Supportive Oncology.
“To our knowledge, this is the first study in CLL patients treated with an immune modulating agent to comprehensively evaluate seroconversion vs multiple viral pathogens that cause ARI,” noted Kevin P. High, MD, MS, of Wake Forest University School of Medicine, Winston-Salem, NC, and colleagues.
The trial randomly assigned 293 patients with early-stage, untreated CLL from January-March 2009 to CVT-E002 200mg twice daily or matching placebo. Patients were stratified by use of prophylactic TMP-SMX, serum IgG, and influenza vaccine status.
They found ARI to be common, with symptoms occurring in 9% of all days from January 1 through March 31 in patients enrolled in the study.
Results showed no significant differences between ARI days (8.5±17.2 for CVT-E002 vs 6.8±13.3 for placebo) and severe ARI days (2.9±9.5 for CVT-E002 vs 2.6±9.8 for placebo).
However, those who received CVT-E002 and had at least 1 ARI was 51% vs 56% in the placebo arm (difference, −5%; 95% CI −16%–7%). In addition, more intense ARI occurred in 32% of CVT-E002 vs 39% of placebo recipients (difference, −7%; 95% CI, −18%–4%), and symptom-specific evaluation showed reduced moderate to severe sore throat (P=0.004) and a lower rate of grade ≥3 toxicities (P=0.02) among CVT-E002 recipients.
Greater seroconversion (4-fold increases in antibody titer) vs 9 common viral pathogens was documented in CVT-E002 recipients (16% vs 7%, P=0.04), most likely reflecting augmented antibody responses.
“Future research should examine whether CVT-E002 can affect antibody titers after immunization in CLL patients, and whether higher doses of CVT-E002 might effectively reduce ARI incidence and severity,” they concluded.