Using controlled clinical trials to learn more about acute drug-induced liver injury.

Drug-induced liver injury (DILI) is of major interest to hepatologists and clinicians in general, patients, government regulators, and the pharmaceutical industry. Understanding why this form of injury occurs only in certain individuals has major implications for the development and availability of drug therapies and in the prevention of these events. A single controlled clinical trial may be unlikely to show cases of such rare events, but in the aggregate, clinical trials offer a unique resource for learning more about individual susceptibility and developing truly predictive new biomarkers for DILI. We pose the question as to whether clinical trials could be modified or improved to provide data that would better answer some of the outstanding issues. At a recent (March 2008) public meeting, experts from academia, industry, and regulatory bodies discussed several major issues regarding liver safety in clinical trials including: what signals of liver injury should justify stopping administration of study drug or allowing it to continue; if deliberate rechallenge should be done and under what circumstances; whether patients with liver disease should be included in clinical trials; and what kinds of new biomarkers will be needed to answer these questions more clearly. Past clinical trials have not provided data to settle those issues, and reliance has defaulted to consensus of expert opinions. Modified and better clinical trials with standardized collection of data and biospecimens are probably the best source of new and potentially valuable information to supplant current rules based on consensus of expert opinions and to understand by what mechanisms and how to distinguish those individuals who are susceptible to severe DILI.

Lipid and apolipoprotein ratios: association with coronary artery disease and effects of rosuvastatin compared with atorvastatin, pravastatin, and simvastatin.

Plasma lipid and apolipoprotein ratios that include both an atherogenic and an antiatherogenic lipid component (eg, total cholesterol/high-density lipoprotein [HDL] cholesterol ratio, low-density lipoprotein [LDL] cholesterol/HDL cholesterol ratio, non-HDL cholesterol/HDL cholesterol ratio, and apolipoprotein [apo] B/apo A-I ratio) have been found to be strong predictors of coronary artery disease (CAD) risk. Three trials that compared the effects of rosuvastatin 10 mg versus atorvastatin 10 mg and 2 trials that compared the effects of rosuvastatin 10 mg versus simvastatin 20 mg and pravastatin 20 mg on lipid ratios in patients with hypercholesterolemia were prospectively designed for pooled analysis. At 12 weeks, in the 3-trial pooled analysis, rosuvastatin 10 mg (n = 389) showed significantly greater reductions in all 4 lipid ratios compared with atorvastatin 10 mg (n = 393) (p <0.001). The mean percent reduction from baseline in the LDL cholesterol/HDL cholesterol ratio was 51% in patients treated with rosuvastatin 10 mg versus 39% in patients treated with atorvastatin 10 mg. In the 2-trial pooled analysis, treatment with rosuvastatin 10 mg (n = 226) also resulted in significantly greater reductions in all 4 lipid ratios compared with both simvastatin 20 mg (n = 249) and pravastatin 20 mg (n = 252) (p <0.001). Mean percent reductions from baseline in the LDL cholesterol/HDL cholesterol ratio were 52%, 39%, and 30% for rosuvastatin 10 mg, simvastatin 20 mg, and pravastatin 20 mg, respectively, in these 2 trials.

Rosuvastatin-induced arrest in progression of renal disease.

Preclinical and limited clinical data suggest that statins decrease the progressive decline in renal function that occurs in patients with renal disease. Pooled analysis of data obtained from a population of hyperlipidemic patients enrolled in the rosuvastatin (Crestor) clinical development program permitted assessment of its effects on renal function both early and later in the course of treatment. Study participants were initially included in controlled clinical trials that evaluated the lipid-lowering efficacy and safety of rosuvastatin when compared with placebo or other lipid-lowering agents (i.e., atorvastatin, simvastatin, pravastatin, cholestyramine, fenofibrate or extended-release niacin). The median duration of treatment with the various doses of statins in these trials was approximately 8 weeks. Following completion of a controlled clinical trial, patients were permitted to enter an open-label extension trial and received rosuvastatin treatment. These data permitted assessment of renal function in a diverse group of over 10,000 patients who received rosuvastatin in its recommended dose range (5-40 mg) for up to 3.8 years. Mean serum creatinine concentrations were lower when compared with baseline both early and later in the course of rosuvastatin treatment. In contrast, no change in mean serum creatinine was observed with placebo. Mean glomerular filtration rates (GFR) predicted from the Modification of Diet in Renal Disease (MDRD) equation were higher when compared with baseline both early and later in the course of rosuvastatin treatment. No change in GFR was observed in the placebo group. Among patients who received long-term rosuvastatin treatment (> or =96 weeks), GFR was unchanged or tended to increase, rather than decrease, when compared with baseline irrespective of age, gender, hypertensive or diabetic status, level of renal function (GFR > or =60 vs. <60 ml/min/1.73 m(2)) at entry or urine dipstick protein status prior to or during the period of treatment. These findings suggest that rosuvastatin may arrest the progression of renal disease.