Oncology phase II clinical trials in 2011: Summary description and comparison to phase II trials in other subspecialties.

Abstract

e17568 Background: Phase II clinical trials in oncology have previously been reported to differ significantly in design compared to trials in other subspecialties. The purpose of this study is to provide a summary description of Phase II oncology clinical trials published in 2011, and to identify persistent major cross-specialty differences in clinical trial design. Methods: Records identified through a computerized literature search on PUBMED were reviewed manually using pre-defined criteria to identify abstracts of Phase II clinical trials published in 2011. The abstracts were classified according to variables including subspecialty, use of control group (active and/or placebo), randomization, blinding, and study conclusions. Trials with positive outcomes were defined as those in which the conclusion indicated that the intervention was safe and effective/worthy of further investigation. Statistical analysis was performed using the chi-squared test. Results: A total of 1,500 abstracts of Phase II clinical trials were identified, of which the majority (75%) describe trials on interventions for neoplastic diseases. Among oncology trials, the largest proportion of abstracts described trials evaluating intervention for hematologic neoplasms (16%), followed by upper and lower gastrointestinal (15%), lung (13%) and breast (11%) cancers. Compared to trials in other subspecialties, oncology trials are significantly less likely to include the use of randomization (17% vs 66%, p < 0.0001), blinding (3% vs 44%, p < 0.0001), and control (13% vs 70%, p < 0.0001). The majority of the abstracts reported positive outcomes (66% for oncology; 74% for the other subspecialties). Among oncology trials, trials utilizing a control group are less likely to report positive outcomes than those without a control group (53% vs 67%, p = 0.002). Conclusions: Major differences in design still exist between Phase II trials in oncology and other subspecialties. Only a minority of oncology trials report the use of randomization, blinding, or control groups. Whether the growing interest in randomized Phase II oncology trials will translate into a larger proportion of such trials in the future remains to be seen.