Effect of Talactoferrin Alfa on the Immune System in Adults With Non-Small Cell Lung Cancer

Background. Talactoferrin alfa (talactoferrin), an agent with immune-stimulating properties, has demonstrated safety and preliminary efficacy in clinical trials. Methods. Ten patients (five males and five females) with stage IV non-small cell lung cancer (NSCLC) in a single-arm pilot study received orally administered talactoferrin (1.5 g, b.i.d.) for up to 24 weeks. Radiographic and immunologic studies were performed at baseline and at weeks 6 and 12. Circulating immune cells (natural killer cells [NKCs], CD4+, CD8+, and regulatory T cells) and systemic cytokine levels were measured to assess immune response. Results. Patients enrolled in the study had received a median of four prior chemotherapy regimens, and all patients were symptomatic. Talactoferrin was well tolerated, with no grade 3 or 4 toxicities. Median time to progression (TTP) and overall survival were 6 weeks and 14.5 weeks, respectively. The four patients with ≥9 weeks TTP had evidence of immunologic activity (three with increased NKC activity). Conclusions. The median of four previous chemotherapy regimens, with elevated levels of interleukin (IL) 6 and tumor necrosis factor-alfa in most patients, suggests these patients were poor candidates for immunotherapy.