U.S. Food and Drug Administration approval summary: omacetaxine mepesuccinate as treatment for chronic myeloid leukemia.

On October 26, 2012, the U.S. Food and Drug Administration (FDA) granted accelerated approval to omacetaxine mepesuccinate (Synribo; Teva Pharmaceuticals USA, Inc., North Wales, PA, http://www.tevausa.com) for the treatment of adult patients with chronic phase (CP) or accelerated phase (AP) chronic myeloid leukemia (CML) with resistance and/or intolerance to two or more tyrosine kinase inhibitors (TKIs). The approval was based on the FDA review of data from 111 patients with CML in CP or in AP who had received two or more prior TKIs, including imatinib. Major cytogenetic response was achieved in 18% of patients with CP, with a median response duration of 12.5 months. Major hematologic response was achieved in 14% of patients with AP, with a median response duration of 4.7 months. The FDA safety evaluation was based on submitted data from 163 patients with CP or AP CML who had received at least one dose of omacetaxine mepesuccinate. The safety evaluation was limited by the single-arm design of the clinical trials as conducted in a small number of previously treated patients. The most common (≥20%) adverse reactions of any grade in enrolled patients included thrombocytopenia, anemia, neutropenia, diarrhea, nausea, fatigue, asthenia, injection site reaction, pyrexia, and infection. The FDA concluded that omacetaxine mepesuccinate has shown activity and a favorable benefit-to-risk profile for the studied population of adult patients with CML (CP or AP) with resistance and/or intolerance to two or more TKIs. Further evidence of response durability to verify clinical benefit is pending.

Postembolization paralysis in a man with a thoracolumbar giant cell tumor.

Giant cell tumors are hypervascular tumors that represent approximately 5% of all primary bone neoplasms. Vertebral tumors often require surgery to maintain spinal stability or to relieve spinal cord and nerve root compression. However, surgical resection of hypervascular tumors like giant cell tumors can be hazardous because of the risk of excessive intraoperative hemorrhage. Preoperative embolization can be useful to decrease perioperative blood loss in primary and metastatic vertebral tumors, and preoperative embolization for vertebral tumor surgery is relatively safe. We report a patient who had the unusual but serious complications of paralysis and paresthesia at the T12 vertebra and below as a result of preoperative embolization. At 6 months followup, the patient was disease-free but without neurologic function from T12 and below. Therefore, it is imperative physicians be aware of the possible preoperative embolization complication of cord infarction and the safety measures proposed in this article to avoid this complication.