Myeloid growth factors (MGFs) are given as supportive care to patients receiving myelosuppressive chemotherapy to reduce the incidence of neutropenia. This selection from the NCCN Guidelines for MGFs focuses on the evaluation of regimen- and patient-specific risk factors for the development of febrile neutropenia (FN), the prophylactic use of MGFs for the prevention of chemotherapy-induced FN, and assessing the risks and benefits of MGF use in clinical practice.

Post-transplant thrombotic microangiopathy (TMA) is a multi-factorial complication of allogeneic hematopoietic cell transplantation (allo-HCT) whose incidence is increased when using a sirolimus plus tacrolimus regimen for acute graft-versus-host disease (aGVHD) prophylaxis. We evaluated the incidence and possible risk factors for TMA in a case series of 177 patients who received allo-HCT using SIR/TAC-based GVHD prophylaxis. Donors were either sibling (n=82) or matched unrelated (n=95). Within the first 100 days post-HCT, 30 (17%) patients were diagnosed with TMA, and an additional nine patients (5%) were classified as probable TMA cases. The median time to TMA onset was 4.6 weeks (range: 1.6-10.6). Thirty-four patients developed both TMA and aGVHD, with the majority of patients (81%) developing aGVHD first. By multivariable analysis, the following factors were found to be associated with increased risk of TMA: day 14 serum sirolimus: ≥9.9 ng/ml (HR: 2.19, 95% CI: 1.13-4.27, p=0.02), presence of prior aGVHD grades II-IV (HR: 3.04, 95% CI: 1.38-6.71, p<0.01), and fully myeloablative conditioning (HR: 3.47, 95% CI: 1.60-7.53, p<0.01). The risk factors for TMA suggest that when using sirolimus/tacrolimus for GVHD prophylaxis, careful monitoring and adjustment of sirolimus dosages is critical, particularly in patients with active aGVHD.

Combination tacrolimus and sirolimus graft-versus-host disease (GVHD) prophylaxis for allogeneic transplant in patients conditioned with a fractionated total body irradiation-based regimen has shown encouraging results. We studied this prophylaxis combination in 85 patients receiving a matched-sibling transplant conditioned with 3 different regimens: fludarabine-melphalan (n ‫؍‬ 46); total body irradiation-etoposide (n ‫؍‬ 28), and busulfan-cyclophosphamide (n ‫؍‬ 11). The conditioning regimens were completed on day ؊4. Sirolimus and tacrolimus were started on day ؊3 to avoid overlap with conditioning therapy. All patients engrafted, with a median time to neutrophil engraftment of 15 days. The cumulative incidence of acute GVHD grades II to IV and III to IV was 43% and 19%, respectively, with no significant difference by conditioning regimen. The 2-year cumulative incidence of chronic GVHD was 46%. With a median follow-up of 26 months, disease-free survival was 58% and overall survival, 66%. The day-100 and 2-year nonrelapse mortality was 4.8% and 10.2%, respectively. The overall incidence of thrombotic microangiopathy was 19%, and it was significantly higher with busulfan/cyclophosphamide (55%, P ‫؍‬ .005). Tacrolimus plus sirolimus is an effective combination for acute GVHD prophylaxis and is associated with very low nonrelapse mortality. Thrombotic microangiopathy is a significant complication with this regimen, particularly in patients receiving busulfan/cyclophosphamide.

Management of febrile neutropenia (FN) is an integral part of supportive care for patients undergoing cancer treatment. The NCCN Guidelines for Hematopoietic Growth Factors provide suggestions for appropriate evaluation, risk determination, prophylaxis, and management of FN. These NCCN Guidelines are intended to guide clinicians in the appropriate use of growth factors for select patients undergoing treatment of nonmyeloid malignancies. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines regarding the incorporation of newly FDA-approved granulocyte-colony stimulating factor biosimilars for the prevention and treatment of FN.

Survival following hematopoietic stem cell transplantation (HSCT) has improved and the number of allogeneic HSCTs performed annually in the United States is expected to reach 10,000 by 2015. The National Marrow Donor Program created the System Capacity Initiative to formulate mechanisms to care for the growing number of HSCT recipients. One proposed method to increase capacity is utilization of pharmacists to manage drug therapy via collaborative practice agreements (CPAs). Pharmacists have managed drug therapy in oncology patients with CPAs for decades; however, there are limited HSCT centers that employ this practice. Engaging in collaborative practice and billing agreements with credentialed pharmacists to manage therapeutic drug monitoring, chronic medical conditions and supportive care in HSCT recipients may be cost-effective and enable physicians to spend more time on new or more complex patients. The goal of this paper is to provide a framework for implementation of a CPA and address how it may improve HSCT program capacity.

Febrile neutropenia, a common side effect of myelosuppressive chemotherapy in patients with cancer, can result in prolonged hospitalization and broad-spectrum antibiotic use, often prompting treatment delays or dose reductions of drug regimens. Prophylactic use of myeloid growth factors (mainly the colony-stimulating factors filgrastim and pegfilgrastim) in patients of heightened risk can reduce the severity and duration of febrile neutropenia. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Myeloid Growth Factors provide recommendations on the use of these agents mainly in the oncology setting based on clinical evidence and expert consensus. This version includes revisions surrounding the issue of timing of pegfilgrastim administration. It also includes new sections on tbo-filgrastim, a recently approved agent that is biologically similar to filgrastim, and the role of myeloid growth factors in the hematopoietic cell transplant setting.

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Allelic variants of genes implicated in drug absorption, distribution, metabolism, and excretion (ADME) determine the pharmacokinetic variability of many medications and are increasingly recognized as important factors determining the success or failure of medical treatments. Both tacrolimus and sirolimus have narrow therapeutic ranges maintained by therapeutic drug monitoring (TDM). Using an ADME Panel that covers >99% of the PharmaADME working group core list (188 single nucleotide polymorphism [SNP] and 12 copy number variant [CNV] assays in 36 pharmacogenetically relevant genes), we studied 177 patients who underwent allogeneic hematopoietic cell transplantation (HCT) using tacrolimus/sirolimus-based graft-versus-host disease (GVHD) prophylaxis. We tested for possible associations between ADME variants and tacrolimus/sirolimus drug levels, concentration/dose (C/D) ratio, and clinical endpoints including acute GVHD. A total of 62 SNP and 6 CNV assays were evaluable after removing the variants which were homozygous in (nearly) all samples. For sirolimus, rs2032582 (ABCB1) T-carriers versus non-T-carriers were associated with higher blood levels (p=0.01), with similar results for C/D ratio. Generalized Estimating Equation (GEE) analysis supported these findings. For tacrolimus, rs776746 CYP3A5*3/*3 and CYP3A5*3/*1 were associated with higher blood levels than CYP3A5*1/*1 (p=0.002). By multivariable analysis, rs776746 CYP3A5*3/*3 and CYP3A5*3/*1 were independently associated with decreased acute GVHD compared to CYP3A5*1/*1, after adjustment for conditioning, donor type, race/ethnicity and age. We demonstrated association of specific ADME genetic polymorphisms with blood levels of tacrolimus/sirolimus, and incidence of acute GVHD post-HCT, in spite of TDM and dose adjustment. A larger ongoing study will determine whether these associations have clinical utility beyond TDM.