Efficacy and safety of a 4-drug fixed-dose combination regimen compared with separate drugs for treatment of pulmonary tuberculosis: the Study C randomized controlled trial.

CONTEXT: Fixed-dose combinations (FDCs) of drugs for treatment of tuberculosis have been advocated to prevent the emergence of drug resistance. OBJECTIVE: To assess the efficacy and safety of a 4-drug FDC for the treatment of tuberculosis. DESIGN, SETTING, AND PATIENTS: The Study C trial, a parallel-group, open-label, noninferiority, randomized controlled trial conducted in 11 sites in Africa, Asia, and Latin America between 2003 and 2008. Patients were 1585 adults with newly diagnosed smear-positive pulmonary tuberculosis. INTERVENTIONS: Patients were randomized to receive daily treatment with 4 drugs (rifampicin, isoniazid, pyrazinamide, ethambutol) given as an FDC (n = 798 patients) or separately (n = 787) in the 8-week intensive phase of treatment. MAIN OUTCOME MEASURE: Favorable treatment outcome, defined as negative culture result at 18 months post randomization and not having already been classified as unfavorable. Noninferiority was dependent on consistent results from a per-protocol and modified intention-to-treat analysis, using 2 different models for the latter, classifying all changes of treatment or refusal to continue treatment (eg, bacteriological failure/relapse, adverse event, default, drug resistance) as unfavorable (model 1) and classifying changes of treatment for reasons other than therapeutic outcomes according to their 18-month bacteriological outcome if available (post hoc model 2). The prespecified noninferiority margin was 4%. RESULTS: In the per-protocol analysis, 555 of 591 patients (93.9%) had a favorable outcome in the FDC group vs 548 of 579 (94.6%) in the separate-drugs group (risk difference, -0.7% [90% confidence interval {CI}, -3.0% to 1.5%]). In the model 1 analysis, 570 of 684 patients (83.3%) had a favorable outcome in the FDC group vs 563 of 664 (84.8%) in the separate-drugs group (risk difference, -1.5% [90% CI, -4.7% to 1.8%]). In the post hoc model 2 analysis, 591 of 658 patients (89.8%) in the FDC group and 589 of 647 (91.0%) in the separate-drugs group had a favorable outcome (risk difference, -1.2% [90% CI, -3.9% to 1.5%]). Adverse events related to trial drugs were similarly distributed among treatment groups. CONCLUSIONS: Compared with a regimen of separately administered drugs, a 4-drug FDC regimen for treatment of tuberculosis satisfied prespecified noninferiority criteria in 2 of 3 analyses. Although the results do not demonstrate full noninferiority of the FDCs compared with single drugs given separately using the strict definition applied in this trial, use of FDCs is preferred because of potential advantages associated with the administration of FDCs compared with separate-drug formulations. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00216333.

Trends in drug-resistant Mycobacterium tuberculosis in New York City, 1991-2003.

BACKGROUND: Two drug-resistance surveys showed a very high prevalence of drug resistance among isolates obtained from patients with tuberculosis in 1991 and 1994 in New York, New York. METHODS: A cross-sectional survey in April 1997 and a survey of incident cases in April-June 2003 were conducted. The trend in the proportion of drug resistance in the 4 surveys was examined separately for prevalent and incident cases. Risk factors for drug resistance in incident cases were also assessed. RESULTS: The number of patients was 251 in the 1997 survey and 217 in the 2003 survey. Among prevalent cases, the percentage of cases with resistance to any antituberculosis drug decreased from 33.5% in 1991 to 23.8% in 1994 and to 21.5% in 1997 (P < .001, by test for trend); cases of multidrug-resistant tuberculosis also decreased significantly, from 19% in 1991 to 6.8% in 1997 (P < .001, by test for trend). Among incident cases in the 4 surveys, the decrease in resistance to any antituberculosis drugs was not statistically significant; however, the decrease in multidrug-resistant tuberculosis (from 9% in 1991 to 2.8% in 2003) was statistically significant (P = .002, by test for trend). However, in 2003, a worrisome increase in incident cases of multidrug-resistant tuberculosis (an increase of 23%) was seen among previously treated patients with pulmonary tuberculosis not born in the United States. Human immunodeficiency virus infection, a strong predictor for drug resistance in 1991 and 1994, was not associated with drug resistance in subsequent surveys. CONCLUSIONS: Intensive case management, including directly observed therapy, adherence monitoring, and periodic medical review to ensure appropriate treatment for each patient, should be sustained to prevent acquired drug resistance.