SummaryHirulog™ (BG8967) is a direct thrombin inhibitor built by rational design using the protein hirudin as a model (Maraganore et al. [1990]; Biochemistry 29: 7095–101). In order to evaluate the therapeutic potential for hirulog in the management of thrombotic disease, the tolerability and anticoagulant activity of the agent were examined in a study of human volunteers.In a randomized, placebo-controlled study (n = 54), the intravenous infusion of hirulog over 15 min showed a rapid, dose-dependent prolongation of activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). There was a corresponding dose-dependent increase in plasma hirulog levels. The peptide was rapidly cleared with a half-life of 36 min and a total body clearance rate for the peptide of 0.43 1 kg−1 h−1. Similar activity was observed following subcutaneous injection but with sustained pharmacodynamic and pharmacokinetic behavior. There was a significant correlation between pharmacokinetic and pharmacodynamic variables for both intravenous (r = 0.8, p <0.001) and subcutaneous administration (r = 0.7, p = 0.002).To evaluate the possible interactions of aspirin on the tolerability and anticoagulant activity of intravenous hirulog, a cross-over design was employed in eight subjects. Aspirin administration did not modify the peptide’s activity. At the administered dose of 0.6 mg kg−1 h−1 for 2 h, hirulog infusion prolonged APTT from 230 to 260% baseline. The infusion of hirulog in subjects who had received aspirin was not associated with any significant changes in the template bleeding time.The final phase of the study examined the activity and tolerability of hirulog in ten subjects during prolonged intravenous infusions for up to 24 h. The peptide (0.3 mg kg−1 h−1) exhibited sustained anticoagulant activity with no evidence for a cumulative effect. During hirulog infusion, APTT was prolonged from 210 to 250% baseline.In all phases of the study, hirulog administration was generally well-tolerated.Our observations show that hirulog is an active antithrombin agent with excellent tolerability in humans. As a direct thrombin inhibitor, hirulog provides a novel approach for the management of thrombotic disease.
A prospective randomized study was conducted to determine the relative effectiveness, toxicity and tolerance of methotrexate (MTX) versus cisplatin (DDP) in patients with recurrent head and neck squamous cell carcinoma. Forty‐four patients were randomized to receive either MTX, 40 mg escalated to 60 mg/m2 IV push weekly, or DDP, 50 mg/m2 6 hour infusion days 1 and 8 every 4 weeks. All patients had objectively measurable disease and a performance status greater than 60% (Karnofsky scale). All had been treated with surgery and/or radiotherapy. No patients had prior chemotherapy. Prior treatment, performance status, and site of primary disease were comparable in both groups. Complete and partial objective responses were achieved in 23.5% of the MTX group and 28.6% of the DDP group (P = 0.51). Median duration of response was 84 days in the MTX group and 92 days in the DDP group. Median survival of patients was 6.1 months with MTX and 6.3 months with DDP. Mucositis was noted in 38% of patients in the MTX group (P = 0.001) compared to none in the DDP group. Vomiting occurred in 87% of patients in the DDP group (P < .0001) compared to 10% of patients in the MTX group. This study demonstrates that in the treatment of recurrent head and neck squamous cell carcinoma, MTX and DDP are equally effective, although MTX appears to be better tolerated. Cancer 52:206‐210, 1983.
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Pure white cell aplasia (PWCA) is a rare manifestation of thymoma. It is characterized by agranulocytosis with absent myeloid precursors in the bone marrow and normal hematopoiesis for other cell lines. Here we describe a 65-year-old female patient who presented with three days of fever and night sweat. Chest CT revealed an anterior mediastinal mass. A biopsy of the mass confirmed a diagnosis of thymoma mixed type A and B2. The patient developed a severe neutropenia, and her bone marrow revealed significantly decreased neutrophil-lineage cells, rare to absent B cells, and defective T cells, consistent with PWCA. Following thymectomy, a complete resolution of PWCA was achieved via multimodality therapy of intravenous immunoglobulins, granulocyte colony-stimulating factor, and immunosuppressant. This report highlights the care complexity regarding treatment choices and decision to perform thymectomy in patients presenting with PWCA.
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