RESUMEN
Advanced-stage non-small cell lung cancer (NSCLC) and small cell lung cancer are cancers in which chemotherapy produces a survival benefit, although it is small. We now know that anti-PD-1/PD-L1 has substantial clinical activity in both of these diseases, with an overall response rate (ORR) of 15%-20%. These responses are frequently rapid and durable, increase median overall survival (OS) compared with chemotherapy, and produce long-term survivors. Despite these very significant results, many patients do not benefit from anti-PD-1/PD-L1. This is because of the potential for malignancies to co-opt myriad immunosuppressive mechanisms other than aberrant expression of PD-L1. Conceptually, these can be divided into three categories. First, for some patients there is likely a failure to generate sufficient functional tumor antigen-specific T cells. Second, for others, tumor antigen-specific T cells may be generated but fail to enter into the tumor parenchyma. Finally, there are a large number of immunosuppressive mechanisms that have the potential to be operational within the tumor microenvironment: surface membrane immune checkpoint proteins PD-1, CTLA-4, LAG3, TIM3, BTLA, and adenosine A2AR; soluble factors and metabolic alterations interleukin (IL)-10, transforming growth factor (TGF)-ß, adenosine, IDO, and arginase; and inhibitory cells, cancer-associated fibroblasts (CAFs), regulatory T cells, myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages. In this article, we discuss three strategies to generate more tumor-reactive T cells for patients: anti-CTLA-4, therapeutic tumor vaccination, and adoptive cellular therapy, with T cells redirected to tumor antigens using T-cell receptor (TCR) or chimeric antigen receptor (CAR) gene modification. We also review some of the various strategies in development to thwart tumor microenvironment immunosuppressive mechanisms. Strategies to drive more T cells into tumors remain a significant challenge.
Asunto(s)
Antígeno B7-H1/uso terapéutico , Antígeno CTLA-4/uso terapéutico , Inmunoterapia , Neoplasias Pulmonares/tratamiento farmacológico , Receptor de Muerte Celular Programada 1/uso terapéutico , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Antígenos de Neoplasias/inmunología , Antígenos de Neoplasias/uso terapéutico , Antígeno B7-H1/inmunología , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/inmunología , Antígeno CTLA-4/inmunología , Humanos , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Receptor de Muerte Celular Programada 1/inmunología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/patología , Microambiente Tumoral/inmunologíaRESUMEN
PURPOSE: Vandetanib is a once-daily oral inhibitor of vascular endothelial growth factor receptor and epidermal growth factor receptor signaling. This randomized, placebo-controlled phase III study assessed the efficacy of vandetanib plus pemetrexed as second-line therapy in advanced non-small-cell lung cancer. PATIENTS AND METHODS: Patients (N = 534) were randomly assigned to receive vandetanib 100 mg/d plus pemetrexed 500 mg/m(2) every 21 days (n = 256) or placebo plus pemetrexed (n = 278). Progression-free survival (PFS) was the primary end point; overall survival, objective response rate, disease control rate, time to deterioration of symptoms, and safety were secondary assessments. RESULTS: There was no significant difference in PFS between treatment arms (hazard ratio [HR], 0.86; 97.58% CI, 0.69 to 1.06; P = .108). Overall survival was also not significantly different (HR, 0.86; 97.54% CI, 0.65 to 1.13; P = .219). Statistically significant improvements in objective response rate (19% v 8%; P < .001) and time to deterioration of symptoms (HR, 0.71; P = .0052; median, 18.1 weeks for vandetanib and 12.1 weeks for placebo) were observed in patients receiving vandetanib. Adding vandetanib to pemetrexed increased the incidence of some adverse events, including rash, diarrhea, and hypertension, while showing a reduced incidence of nausea, vomiting, anemia, fatigue, and asthenia with no reduction in the dose intensity of pemetrexed. CONCLUSION: This study did not meet the primary end point of statistically significant PFS prolongation with vandetanib plus pemetrexed versus placebo plus pemetrexed. The vandetanib combination showed a significantly higher objective response rate and a significant delay in the time to worsening of lung cancer symptoms versus the placebo arm as well as an acceptable safety profile in this patient population.