Assessment of the consistency and robustness of results from a multicenter trial of remission maintenance therapy for acute myeloid leukemia

<p>Abstract</p> <p>Background</p> <p>Data from a randomized multinational phase 3 trial of 320 adults with acute myeloid leukemia (AML) demonstrated that maintenance therapy with 3-week cycles of histamine dihydrochloride plus low-dose interleukin-2 (HDC/IL-2) for up to 18 months significantly improved leukemia-free survival (LFS) but lacked power to detect an overall survival (OS) difference.</p> <p>Purpose</p> <p>To assess the consistency of treatment benefit across patient subsets and the robustness of data with respect to trial centers and endpoints.</p> <p>Methods</p> <p>Forest plots were constructed with hazard ratios (HRs) of HDC/IL-2 treatment effects versus no treatment (control) for prospectively defined patient subsets. Inconsistency coefficients (I²) and interaction tests (X²) were used to detect any differences in benefit among subsets. Robustness of results to the elimination of individual study centers was performed using "leave-one-center-out" analyses. Associations between treatment effects on the endpoints were evaluated using weighted linear regression between HRs for LFS and OS estimated within countries.</p> <p>Results</p> <p>The benefit of HDC/IL-2 over controls was statistically consistent across all subsets defined by baseline prognostic variables. I²and <it>P</it>-values of X²ranged from 0.00 to 0.51 and 0.14 to 0.91, respectively. Treatment effects were statistically significant in 14 of 28 subsets analyzed. The "leave-one-center-out" analysis confirmed that no single center dominated (<it>P</it>-values ranged from 0.004 to 0.020 [mean 0.009]). The HRs representing the HDC/IL-2 effects on LFS and OS were strongly correlated at the country level (R²= 0.84).</p> <p>Limitations</p> <p>Small sample sizes in some of the subsets analyzed.</p> <p>Conclusions</p> <p>These analyses confirm the consistency and robustness of the HDC/IL-2 effect as compared with no treatment. LFS may be an acceptable surrogate for OS in future AML trials. Analyses of consistency and robustness may aid interpretation of data from multicenter trials, especially in populations with rare diseases, when the size of randomized clinical trials is limited.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00003991">NCT00003991</a></p

Комбинированная антигипертензивная терапия у больных артериальной гипертензией, перенесших острую респираторную вирусную инфекцию

ГИПЕРТЕНЗИЯ /ЛЕК ТЕРКРОВЕНОСНЫХ СОСУДОВ БОЛЕЗНИКОМБИНИРОВАННОЕ ЛЕЧЕБНОЕ ВОЗДЕЙСТВИЕАНТИГИПЕРТЕНЗИВНЫЕ СРЕДСТВА /ТЕР ПРИМРЕСПИРАТОРНЫЕ ИНФЕКЦИИ /ОСЛВИРУСНЫЕ БОЛЕЗНИ /ОС

Leukemia-free survival as a surrogate end point for overall survival in the evaluation of maintenance therapy for patients with acute myeloid leukemia in complete remission

Background In trials designed to evaluate new therapies for hematologic malignancies, end points such as leukemia-free survival are often used as surrogates for overall survival in acute leukemia. We aimed to assess whether leukemia-free survival is an acceptable statistical surrogate for overall survival when applied to remission maintenance therapy for acute myeloid leukemia. Design and Methods Data were analyzed from a randomized Phase III trial of remission maintenance immunotherapy with histamine dihydrochloride plus low-dose interleukin-2 versus no treatment in adults with acute myeloid leukemia. A two-stage surrogate validation model was applied in which correlations between Kaplan-Meier estimates of leukemia-free survival and overall survival, and between log hazard ratios reflecting treatment effects were analyzed. Country of patient enrollment was the unit of analysis. Results Kaplan-Meier estimates of overall survival at 36, 48, and 60 months and leukemia-free survival at 24 months were reasonably correlated (R 2 ranging from 0.44 to 0.84) both for the overall (n=320) and first complete remission (n=261) populations. The effects of histamine dihydrochloride/ interleukin-2 on log hazard ratios for leukemia-free survival and overall survival were well correlated (R 2=0.88-0.93). Conclusions The significant correlations between overall survival and the surrogate end point (leukemia-free survival) and between the effect of histamine dihydrochloride/interleukin-2 on leukemia-free survival and overall survival satisfy the two-stage surrogate validation model. © 2011 Ferrata Storti Foundation.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Fludarabine, Cyclophosphamide, Anti-Thymocyte Globulin, with or without “ 2Gy TBI, for Alternative Donor Transplants in Acquired Aplastic Anemia (SAA): A Report From the EBMT SAA Working Party.

Fludarabine, Cyclophosphamide, Anti-Thymocyte Globulin, with or without “ 2Gy TBI, for Alternative Donor Transplants in Acquired Aplastic Anemia (SAA