Retrospective analysis of the safety and efficacy of interleukin-2 after prior VEGF-targeted therapy in patients with advanced renal cell carcinoma.

Agents targeting vascular endothelial growth factor (VEGF) signaling have been advocated as frontline therapy for advanced renal cancer. The role of interleukin 2 (IL-2) therapy after resistance to VEGF-targeted therapy remains unexplored. We conducted a retrospective analysis of the tolerability and efficacy of IL-2 therapy in patients who had previously received VEGF-targeted therapy. Twenty-three consecutive patients who received salvage IL-2 therapy were analyzed. Fifteen patients had received prior tyrosine kinase inhibitors (TKIs) (sorafenib or sunitinib), whereas 8 patients had received bevacizumab alone. Six of 23 patients did not receive week 2 of cycle 1 of treatment. All 6 of these patients had received prior TKIs. The incidence of severe cardiac toxicities, including 1 sudden cardiac death, in patients receiving prior TKI was 40% (95% confidence interval, 16.3-67.7%), significantly higher than what is expected from historical experience. Only 1 of 23 patients proceeded to receive a second cycle of IL-2. No patients achieved a partial or complete response to therapy. This retrospective analysis highlights unexpected and severe cardiac toxicities in patients receiving IL-2 after VEGF-targeted TKI therapy. The assumption that IL-2 therapy can be safely administered after TKI therapy may not be valid. Further examination of the safety of this sequential approach is necessary and more cautious patient selection seems warranted.

Sirolimus-based graft-versus-host disease prophylaxis protects against cytomegalovirus reactivation after allogeneic hematopoietic stem cell transplantation: a cohort analysis.

Sirolimus-based immunosuppressive regimens in organ transplantation have been associated with a lower than expected incidence of cytomegalovirus (CMV) disease. Whether sirolimus has a similar effect on CMV reactivation after allogeneic hematopoietic stem cell transplantation (HSCT) is not known. We evaluated 606 patients who underwent HSCT between April 2000 and June 2004 to identify risk factors for CMV reactivation 100 days after transplantation. The cohort included 252 patients who received sirolimus-tacrolimus for graft-versus-host disease (GVHD) prophylaxis; the rest received non-sirolimus-based regimens. An initial positive CMV DNA hybrid capture assay was observed in 225 patients (37.1%) at a median 39 days after HSCT for an incidence rate of 0.50 cases/100 patient-days (95% confidence interval [CI], 0.44-0.57). Multivariable Cox modeling adjusting for CMV donor-recipient serostatus pairs, incident acute GVHD, as well as other important covariates, confirmed a significant reduction in CMV reactivation associated with sirolimus-tacrolimus-based GVHD prophylaxis, with an adjusted HR of 0.46 (95% CI, 0.27-0.78; P = .004). The adjusted HR was 0.22 (95% CI, 0.09-0.55; P = .001) when persistent CMV viremia was modeled. Tacrolimus use without sirolimus was not significantly protective in either model (adjusted HR, 0.66; P = .14 and P = .35, respectively). The protective effect of sirolimus-containing GVHD prophylaxis regimens on CMV reactivation should be confirmed in randomized trials.