Long-term treatment with romiplostim in patients with chronic immune thrombocytopenia: safety and efficacy.

Romiplostim was effective, safe, and well-tolerated over 6-12 months of continuous treatment in Phase 3 trials in patients with immune thrombocytopenia (ITP). This report describes up to 5 years of weekly treatment with romiplostim in 292 adult ITP patients in a long-term, single-arm, open-label study. Outcome measures included adverse events (including bleeding, thrombosis, malignancy, and reticulin/fibrosis), platelet response (platelet count >50 × 10(9) per litre), and the proportion of patients requiring rescue treatments. Treatment-related serious adverse events were infrequent and did not increase with longer treatment. No new classes of adverse events emerged. Thrombotic events occurred in 6.5% of patients and were not associated with platelet count. Median platelet counts of 50-200 × 10(9) per litre were maintained with stable doses of romiplostim (mean 5-8 µg/kg; generally self-administered at home) throughout the study. A platelet response was achieved at least once by 95% of patients, with a platelet response maintained by all patients on a median 92% of study visits. There was a low rate of bleeding and infrequent need for rescue treatments. In conclusion, this study demonstrated that romiplostim was safe and well-tolerated over 614 patient-years of exposure in ITP patients, and that efficacy was maintained with stable dosing for up to 5 years of continuous treatment.

Elevated activated partial thromboplastin time during administration of first-generation adenoviral vectors for gene therapy for prostate cancer: identification of lupus anticoagulants.

OBJECTIVES: To evaluate the cause and significance of elevated activated partial thromboplastin time (aPTT) in a group of patients who received a first-generation adenoviral vector (Ad-OC-TK) delivering a toxic gene to prostate cancer cells as part of a Phase I clinical trial at the University of Virginia. METHODS: Eleven subjects were injected intratumorally to metastatic lesions of prostate cancer in the prostatic fossa, retroperitoneal lymph nodes, or bone (iliac, ischium, or vertebrae). After the initial laboratory evaluation, patients with elevated aPTT underwent a series of additional tests, including mixing studies, coagulation factor, prekallikrein, and high-molecular-weight kininogen, and lupus anticoagulant studies (modified Russell viper venom time) with phospholipid correction, and a Staclot LA assay. RESULTS: Of the 11 subjects who were enrolled in the trial, 6 had elevated aPTT values. Of the 6 patients, 3 had aPTT elevation of more than 10 seconds above normal. Two of the subjects with higher values demonstrated an inhibitory pattern with the factor VIII and XI assays, and the lupus anticoagulant studies were positive. No clinical sequelae to the elevated aPTT values were observed. CONCLUSIONS: This is, to our knowledge, the first formal report of a first-generation adenoviral vector causing a slight transient elevation of the aPTT through the induction of an antiphospholipid antibody. No clinical sequelae related to elevated aPTT values were observed. The adenoviral protocol was safe; similar protocols should be aware of this phenomenon.