Risk factors associated with palbociclib-induced neutropenia in patients with metastatic breast cancer.

BACKGROUND: Neutropenia is the most common adverse event with palbociclib, an oral cyclin-dependent kinase 4/6 inhibitor, with grade 3/4 neutropenia occurring in up to 67% of patients in phase III trials evaluating this agent in metastatic breast cancer. This retrospective chart review assessed characteristics of patients on palbociclib to evaluate for risk factors in the development of grade 3/4 neutropenia. PATIENTS AND METHODS: Patients with metastatic breast cancer who received palbociclib were included. Patient demographics collected included age, gender, race, body mass index, breast cancer treatment history, palbociclib starting dose, baseline absolute neutrophil count, baseline platelet count, concomitant hormonal therapy, concomitant use of denosumab, and use of concomitant strong CYP3A4 inhibitors/inducers. Events of interest occurring within 30 days of initiation of palbociclib were also noted including antibiotic and corticosteroid use, mucosal conditions, open wounds, or surgery. The incidence and potential risk factors for grade 3/4 neutropenia in the first 6 months of treatment were analyzed. RESULTS: A total of 257 patients were included in the analysis with 206 patients (80.2%) and 139 patients (54.1%) experiencing all-grade neutropenia and grade 3/4 neutropenia, respectively. Multivariate analysis found baseline myelosuppression and recent antibiotic use to be independent predictors of grade 3/4 neutropenia. Normal weight patients had an increased risk for grade 3/4 neutropenia compared to obese patients by multivariate analysis. CONCLUSION: The results of this study showed baseline myelosuppression and recent antibiotic use within 30 days of palbociclib initiation were predictive of a higher incidence of grade 3/4 neutropenia. Obese patients were less likely to develop grade 3/4 neutropenia compared to normal weight patients.

Implementation, utilization, and evaluation of a pharmacist-driven romiplostim dosing service for patients with immune thrombocytopenia at a multisite cancer centre.

INTRODUCTION: Romiplostim is a thrombopoietin receptor agonist approved for the treatment of patients with chronic immune thrombocytopenia who have had an insufficient response to corticosteroids, immune globulin, or splenectomy. Dose adjustments of romiplostim are based on platelet counts and follow a dosing schema that requires frequent monitoring. As a quality improvement initiative to increase clinical efficiency and promote clinical pharmacy services at our institution, we developed a collaborative practice agreement and implemented a novel pharmacist-driven romiplostim dosing protocol. METHODS: A retrospective chart review was conducted to evaluate the acceptance, utilization, and impact of the pharmacist-driven romiplostim dosing service. The primary outcome of our analysis was the adoption rate by providers of the romiplostim pharmacist dosing service. Secondary endpoints were focused on patients newly initiating romiplostim on the dosing service and included platelet responses and number of dose adjustments by a pharmacist. RESULTS: A total of 54 patients received romiplostim in our analysis: 25 patients who had already been receiving romiplostim and 29 patients who newly initiated romiplostim during the study period. Of the 29 patients newly initiating romiplostim, 27 (93%) had their dosing managed by a pharmacist Twenty-one patients (84%) and 18 patients (75%) achieved an initial and durable response with romiplostim, respectively. Pharmacists made a median of 3 dose adjustments to romiplostim per patient. CONCLUSION: The implementation of a pharmacist-driven romiplostim dosing service led to a significant adoption and utilization by physicians at our health system.

Olaratumab: A New Strategy in the Treatment of Advanced Soft-Tissue Sarcoma.

Olaratumab is a monoclonal antibody that recently received accelerated approval for the treatment of advanced soft-tissue sarcomas in combination with doxorubicin for a histologic subtype in which anthracycline-containing regimens is appropriate and disease is not amenable to curative surgery or radiotherapy. It inhibits platelet-derived growth factor receptor alpha, leading to the inhibition of tumor cell proliferation, angiogenesis, and metastasis. In a phase II clinical trial, olaratumab in combination with doxorubicin met its predefined primary endpoint of improving progression-free survival and secondary endpoint of overall survival compared to doxorubicin monotherapy in patients with advanced soft-tissue sarcoma. Common adverse events associated with the combination of olaratumab and doxorubicin include nausea, mucositis, neutropenia, and infusion-related reactions.