Phase I study of GSK461364, a specific and competitive Polo-like Kinase 1 (PLK1) inhibitor in patients with advanced solid malignancies.

Purpose: GSK461364 is an ATP-competitive inhibitor of polo-like kinase 1 (Plk1). A phase I study of two schedules of intravenous GSK461364 was conducted. Experimental Design: GSK461364 was administered in escalating doses to patients with solid malignancies by two schedules, either on days 1, 8, and 15 of 28-day cycles (schedule A) or on days 1, 2, 8, 9, 15, and 16 of 28-day cycles (schedule B). Assessments included pharmacokinetic and pharmacodynamic profiles, as well as marker expression studies in pretreatment tumor biopsies. Results: Forty patients received GSK461364: 23 patients in schedule A and 17 in schedule B. Dose-limiting toxicities (DLT) in schedule A at 300 mg (2 of 7 patients) and 225 mg (1 of 8 patients) cohorts included grade 4 neutropenia and/or grade 3–4 thrombocytopenia. In schedule B, DLTs of grade 4 pulmonary emboli and grade 4 neutropenia occurred at 7 or more days at 100 mg dose level. Venous thrombotic emboli (VTE) and myelosuppression were the most common grade 3–4, drug-related events. Pharmacokinetic data indicated that AUC (area under the curve) and C max (maximum concentration) were proportional across doses, with a half-life of 9 to 13 hours. Pharmacodynamic studies in circulating tumor cells revealed an increase in phosphorylated histone H3 (pHH3) following drug administration. A best response of prolonged stable disease of more than 16 weeks occurred in 6 (15%) patients, including 4 esophageal cancer patients. Those with prolonged stable disease had greater expression of Ki-67, pHH3, and Plk1 in archived tumor biopsies. Conclusions: The final recommended phase II dose for GSK461364 was 225 mg administered intravenously in schedule A. Because of the high incidence (20%) of VTE, for further clinical evaluation, GSK461364 should involve coadministration of prophylactic anticoagulation.

A patient perspective of pharmacist prescribing: 'crossing the specialisms-crossing the illnesses'

Background: The drive for non-medical prescribing has progressed quickly since the late 1990s and involves a range of healthcare professionals including pharmacists. As part of a commissioned research project, this qualitative element of a larger case study focused on the views of patients of pharmacist prescribers. 

Objective: The aim of this study was to explore patients' perspectives of pharmacists as prescribers. 

Methods: Three pharmacists working as independent prescribers in the clinical areas of (i) hypertension, (ii) cardiovascular/diabetes management, (iii) anticoagulation were recruited to three case studies of pharmacist prescribing in Northern Ireland. One hundred and five patients were invited to participate in focus groups after they had been prescribed for by the pharmacist. Focus groups took place between November 2010 and March 2011 (ethical/governance approvals granted) were audio taped, transcribed verbatim, read independently by two authors and analysed using constant comparative analysis. 

Results: Thirty-four patients agreed to participate across seven focus groups. Analysis revealed the emergence of one overarching theme: team approach to patient care. A number of subthemes related to the role of the pharmacist, the role of the doctor and patient benefits. There was an overwhelming lack of awareness of pharmacist prescribing. Patients discussed the importance of a multidisciplinary approach to their care and recognized limitations of the current model of prescribing. 

Conclusion: Patients were positive about pharmacist prescribing and felt that a team approach to their care was the ideal model especially when treating those with more complex conditions. Despite positive attitudes, there was a general lack of awareness of this new mode of practice.