Carfilzomib in multiple myeloma patients with renal impairment: pharmacokinetics and safety.

This phase 2 study assessed the safety, pharmacokinetics, pharmacodynamics and efficacy of carfilzomib, a selective proteasome inhibitor, in patients with multiple myeloma and varying degrees of renal impairment, including patients on chronic hemodialysis. Patients were grouped by creatinine clearance: >80 ml/min, 50-80 ml/min, 30-49 ml/min, <30 ml/min and chronic hemodialysis. Carfilzomib was administered on days 1, 2, 8, 9, 15 and 16 in 28-day cycles: 15 mg/m(2) (Cycle 1), 20 mg/m(2) (Cycle 2) and 27 mg/m(2) (Cycles 3+). There were no differences in carfilzomib clearance or exposure among patients with normal renal function and any group with renal impairment. Grade 3/4 adverse events (AEs) included anemia (28.0%), thrombocytopenia (20.0%), lymphopenia (18.0%) and fatigue (14.0%). AEs were similar among groups. At 15 mg/m(2), proteasome inhibition up to 85% was observed and did not differ among groups. Although nearly 50% of patients were refractory to both bortezomib and lenalidomide, end of study partial response or better (overall response rate) was 25.5% with 7.9 months median duration of response. In conclusion, the pharmacokinetics and safety of carfilzomib were not influenced by the degree of baseline renal impairment, including in patients on dialysis, and carfilzomib was well tolerated and demonstrated promising efficacy.

Prevention of thalidomide- and lenalidomide-associated thrombosis in myeloma.

The incidence of venous thromboembolism (VTE) is more than 1 per thousand annually in the general population and increases further in cancer patients. The risk of VTE is higher in multiple myeloma (MM) patients who receive thalidomide or lenalidomide, especially in combination with dexamethasone or chemotherapy. Various VTE prophylaxis strategies, such as low-molecular-weight heparin (LMWH), warfarin or aspirin, have been investigated in small, uncontrolled clinical studies. This manuscript summarizes the available evidence and recommends a prophylaxis strategy according to a risk-assessment model. Individual risk factors for thrombosis associated with thalidomide/lenalidomide-based therapy include age, history of VTE, central venous catheter, comorbidities (infections, diabetes, cardiac disease), immobilization, surgery and inherited thrombophilia. Myeloma-related risk factors include diagnosis and hyperviscosity. VTE is very high in patients who receive high-dose dexamethasone, doxorubicin or multiagent chemotherapy in combination with thalidomide or lenalidomide, but not with bortezomib. The panel recommends aspirin for patients with < or = 1 risk factor for VTE. LMWH (equivalent to enoxaparin 40 mg per day) is recommended for those with two or more individual/myeloma-related risk factors. LMWH is also recommended for all patients receiving concurrent high-dose dexamethasone or doxorubicin. Full-dose warfarin targeting a therapeutic INR of 2-3 is an alternative to LMWH, although there are limited data in the literature with this strategy. In the absence of clear data from randomized studies as a foundation for recommendations, many of the following proposed strategies are the results of common sense or derive from the extrapolation of data from many studies not specifically designed to answer these questions. Further investigation is needed to define the best VTE prophylaxis.

A phase II trial of bryostatin 1 in the treatment of metastatic colorectal cancer.

Current chemotherapy for patients with advanced colorectal cancer is relatively ineffective and may be associated with significant toxicity. Bryostatin 1 (bryo 1) influences cell proliferation, intracellular metabolism and signaling, differentiation, and apoptosis in human cancer cell lines via modulation of protein kinase C (PKC) activity. This trial investigates the efficacy and toxicity of bryo 1 as a novel therapeutic agent for patients with advanced colorectal cancer who have had previous 5-fluorouracil therapy. The primary end point was tumor response to bryo 1. Toxicity was also assessed. Twenty-eight patients with advanced colorectal cancer were enrolled. The mean age was 59 years (range, 38-76), with 16 men and 12 women, and good minority representation (11 African-Americans). The first 10 patients initially received 25 microg/m2 of bryo 1 weekly as a 24-h infusion for 3 weeks of every 4-week cycle, with dose escalation to 35 microg/m2 starting with the second cycle. The remaining patients were started at 35 microg/m2 and escalated to 40 microg/m2, if toxicity was minimal. Twenty-five patients were evaluable for objective tumor response, and complete data on toxicity were collected on 26 patients. No partial or complete tumor responses were observed. All 25 patients had disease progression within four cycles. Myalgia was the most common toxicity. Myelosuppression was not seen. bryo 1 as a weekly 24-h continuous infusion lacks single-agent antitumor activity in advanced colorectal cancer. Toxicity differs from that of traditional chemotherapeutic drugs.