Response-rate analysis

Several randomized trials have demonstrated that leuprolide and goserelin are effective agents when used alone in patients with advanced prostate cancer.19 Response rates around 80% have been reported, with a lower incidence of adverse effects compared with estrogens.19 There are no direct comparative trials of the currently available LHRH agonists or the dosage formulations, but a recent meta-analysis reported that there is no difference in efficacy or toxicity between leuprolide and goserelin. Therefore, the choice between the two usually is made based on cost and patient and physician preference for a dosing schedule. 

A pooled analysis of 14 875 adults (Hispanic, n = 361 White, n = 10 108 African American, n = 547 Asian, n = 112) who participated in 104 double-blind, placebo-controlled paroxetine trials for mood and anxiety disorders was performed to ascertain minority group differences (Roy-Byrne et al., 2005). There were significant differences in rates of response by ethnicity (p = 0.014) with the odds of responding being lower for the Asian and Hispanic subjects compared to the African American and White subjects. There was also a higher placebo response rate in Hispanic subjects. Rapidity of response and emergence of adverse effects were similar across groups. 

Sneed, Joel R., Bret R. Rutherford, David Rindskopf, David T. Lane, Harold A. Sackeim and Steven P. Roose, Design Makes a Difference A Meta-Analysis of Antidepressant Response Rates in Placebo-Controlled Versus Comparator Trials in Late-Life Depression , American Journal of Geriatric Psychiatry 16, no. 1 (2008) 65-73... 

Capecitabine monotherapy is suitable for first-line therapy in patients not likely to tolerate IV chemotherapy. Capecitabine produced superior response rates and comparable survival compared with 5-FU and leucovorin in a pooled analysis. Capecitabine is being evaluated in combination with irinote-can or oxaliplatin. 

The immunoconjugate of doxorubicin with a chimeric anti-Le -related, tumour-associated antigen expressed on most human carcinomas, was evaluated in phase I [132] and phase II [133] clinical trials. The phase II trial performed in patients with metastatic breast carcinoma showed low clinical response rates. These data together with tumour biopsy analysis suggest that the dose that could be safely administered was insufficient to maintain the intra-tu-... 

The use of weekly paclitaxel (45 mg/m2) and carboplatin (100 mg/m2) has been reported (135,136). This combination as used to treat 62 patients with stage III and IV squamous cell carcinoma of the head and neck concurrently with radical radiotherapy lead to a clinical complete response rate of 75 % both at the primary and in the neck with a median survival of 33 mo (135). The authors report a retrospective comparison to similar patients treated with concurrent carboplatin alone or concurrent carboplatin and bleomycin and show on multivariate analysis that complete response and treatment with paclitaxel were predictive for survival (136). This result while encouraging is retrospective in nature and is subject to potential bias. 

Another meta-analysis of placebo-controlled trials in depression published between 1980 and 2000 showed an increase in the response rates in the placebo arms of trials with a variety of antidepressants (Walsh et al.y 2002). Responses to placebo increased significantly in recent years, as shown by the high positive correlation with the year of publication. The association between response rate and year of publication was more statistically robust for placebo than for active medication. The change in placebo response rate did not appear to be explained directly by changes in study characteristics such as patient age, placebo lead-in or minimum required Hamilton Rating Scale for Depression score. A potential explanation could be the changing awareness of patients and the fact that many patients in recent clinical trials had been exposed to several previous treatments and thus expected to improve (see Box 5.4). 

The overall efficacy of ECT was 78%, which is significantly superior to that of tricyclic antidepressants, whose overall efficacy was 64%, as well as to placebo, simulated ECT, and the monoamine oxidase inhibitors, whose overall response rates ranged from 28% to 38%. This difference was particularly striking because many patients in the ECT-treated groups had failed previous drug trials. The adequacy of some of these, however, was questionable. Furthermore, in contrast to other reports, our analysis did not find a significant difference favoring BILAT over UND ECT (i.e., only a 7% overall difference). 

In a case-control study in the north of Sweden, Hallquist et al. (1993) compared 188 men and women aged 20-70 years who had thyroid cancer with age- and sex-matched controls (two per case) selected from a register of the local population. The cases were identified retrospectively from a cancer registry and excluded a proportion of patients (19%) who had died by the time of the study. Exposure to potential risk factors, including chlorophenols, was ascertained by postal questionnaire with a supplementary telephone interview if answers were incomplete. The response rates for the cases and controls were 95% and 90%, respectively. Of the 171 cases analysed, 107 had papillary tumours. Four cases and three controls reported exposure to chlorophenols (odds ratio, 2.8 95% CI, 0.5-18). [The Working Group noted that the method of statistical analysis was not the most appropriate for individually matched data, but this is unlikely to have produced serious bias.]... 

In spite of all their advantages, sensitivity and selectivity, bio-sensors, however, do possess disadvantages connected with thermal and timely instability, high cost of bio-receptors and the need to add substrates in the solution under analysis as signal-generating substances. Some attempts to synthesize and use as receptors chemical organic catalytic systems, which will ensure the required selectivity and response rate, have become the basis for developing enzyme-free sensors [11], or biomimetic sensors. 

Gefitinib is a tyrosine kinase inhibitor that targets the tumor protein, epidermal growth factor receptor (EGFR), and was approved by FDA for advanced non-small cell lung cancer in May 2003. The overall response rate in the United States was about 10% (w = 216). A subset analysis revealed... 

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