Optimal conditioning therapy for hematopoietic cell transplantation (HCT) in acute myelogenous leukemia (AML) remains undefined. We retrospectively compared outcomes of a consecutive series of 51 AML patients treated with oral busulfan (1 mg/kg every 6 hours for 4 days) and cyclophosphamide (60 mg/kg IV × 2 days) - (Bu/Cy) with 100 consecutive AML patients treated with pharmacokinetic targeted IV busulfan (AUC < 6000 μM/L*min per day × 4 days) and fludarabine (40 mg/m2 × 4 days) - (t-IV Bu/Flu). The Bu/Cy and t-IV Bu/Flu groups significantly differed according to donor relation, stem cell source, aGVHD prophylaxis, remission status, primary vs. secondary disease, median age, and % blasts prior to HCT (p < 0.01 for each). Conditioning with t-IV Bu/Flu reduced early toxicity including idiopathic pneumonia syndrome (IPS) and hepatic veno-occlusive disease (VOD). Additionally, the trajectory of early NRM (100 day: 16% vs. 3%, and1 year: 25% vs. 15% for Bu/Cy and t-IV Bu/Flu, respectively) favored t-IV Bu/Flu. Grade II-IV aGVHD (48% vs. 82%, p < 0.0001), as well as moderate/severe cGVHD (7% vs. 40%, p < 0.0001) differed between the Bu/Cy and t-IV Bu/Flu groups, due to the predominance of peripheral blood stem cells in the t-IV Bu/Flu group. Pharmacokinetic targeting of intravenous busulfan in combination with fludarabine is associated with reduced conditioning regimen related toxicity compared to oral busulfan and cyclophosphamide. However, multivariable analysis did not demonstrate significant differences in overall survival (p = 0.78) or non-relapse mortality (p = 0.6) according to conditioning regimen delivered.
Chimeric antigen receptor T-cell (CAR-T) therapy has emerged as a breakthrough treatment for relapsed and refractory multiple myeloma (RRMM). However, these products are complex to deliver, and alternative options are now available. Identifying biomarkers that can predict therapeutic outcomes is crucial for optimizing patient selection. There is a paucity of data evaluating the utility of both serum soluble B-cell maturation antigen (sBCMA) levels and metabolic tumor volume (MTV) at baseline in patients with RRMM undergoing CAR-T therapy. We identified a cohort of 183 patients with available serum to measure sBCMA and/or pretreatment MTV, derived from positron emission tomography–computed tomography scans obtained per standard of care. Expectedly, high pretreatment levels of sBCMA correlated with other established markers of tumor burden (eg, bone marrow plasma cells and β2 microglobulin) and inflammation and were highly prognostic for CAR-T–related toxicities and inferior progression-free survival (PFS). High MTV values were also associated with shorter PFS and inferior overall survival. The poor correlation observed between these 2 measures prompted evaluation of those with discordant results, identifying that those with low sBCMA and high MTV frequently had low/absent BCMA expression on plasma cells and suboptimal response. Our findings highlight the potential utility of sBCMA and MTV to facilitate more personalized treatment strategies in the management of RRMM eligible for BCMA-directed CAR-T.
Anthracycline-based cardiotoxicity is concerning for women with breast cancer and portends a dose-dependent risk of developing left ventricular dysfunction. Overall, the prevalence of heart failure (HF) is ≈2% of the total US population; however, BRCA-deficient mice have shown increased HF. We evaluated for the inherent risk of HF in women with BRCA mutations to determine whether treatment with anthracycline-based therapy increased this risk. We obtained results on BRCA mutation carriers regarding cancer treatment and HF, identified through the BRCA patient advocacy organization Facing Our Risk for Cancer Empowered (FORCE) and the Moffittbased Inherited Cancer Registry. In our patient group (232 BRCA1 and 159 BRCA2 patients; 10 with both mutations), 7.7% reported HF, with similar proportions in BRCA1 versus BRCA2 carriers (7.4% and 8.2%, respectively). These proportions are significantly higher than published rates (p < 0.001). There was no statistically significant difference in HF rates comparing anthracycline-treated versus anthracycline-naïve patients however (7.1% vs. 8.3%; p = 0.67). In addition, 9.1% of BRCA1 carriers and 8.2% of BRCA2 carriers reported arrhythmias. BRCA mutation carriers showed increased risk of cardiotoxicity versus the general population and an overall increased risk of cardiotoxicity from anthracycline-based therapy. Our study supports data that BRCA carriers have increased noncancer mortality from cardiotoxicity. A prospective trial to determine HF and conduction abnormalities in this population is warranted.
11 November 2016 in Communications in Statistics - Simulation and Computation
The beta-binomial model has been widely used as an analytically tractable alternative that captures the overdispersion of an intra-correlated, binomial random variable, X. However, the model validation for X has been rarely investigated. As a beta-binomial mass function takes on a few different shapes, the model validation is examined for each of the classified shapes in this article. Further, the mean square error (MSE) is illustrated for each shape by the maximum likelihood estimator (MLE) based on a beta-binomial model approach and the method of moments estimator (MME) in order to gauge when and how much the MLE is biased.